#Linear Models with R by Julian Faraway
#chapter 9 Pricipal Component Analysis

library(faraway)
# library(help=faraway)
# A Tecator Infratec Food and Feed Analyzer working
# in the wavelength range of 850 to 1050 nm by the near
# infrared transmission (NIT) principle was used to 
# collect data on samples of finely chopped pure meat.
# 215 samples were measured. For each sample, the fat 
# content was measured along with a 100 channel spectrum
# of absorbances. Since determining the fat content
# via analytical chemistry is time consuming,
# we would like to build a model to predict the fat content
# of new samples using the 100 absorbances
# which can be measured more easily. See Thodberg (1993).
# The true performance of any model is hard to determine
# based on just the fit to the available data. We need to
# see how well the model does on new data not used in the
# construction of the model. For this reason, we will
# partition the data into two parts—a training sample 
# consisting of the first 172 observations that will be
# used to build the models and a testing sample of the
# remaining 43 observations. Let’s start with the least 
# squares fit:
  
data("meatspec")
str(meatspec)
## 'data.frame':    215 obs. of  101 variables:
##  $ V1  : num  2.62 2.83 2.58 2.82 2.79 ...
##  $ V2  : num  2.62 2.84 2.58 2.82 2.79 ...
##  $ V3  : num  2.62 2.84 2.59 2.83 2.79 ...
##  $ V4  : num  2.62 2.85 2.59 2.83 2.79 ...
##  $ V5  : num  2.62 2.85 2.59 2.83 2.8 ...
##  $ V6  : num  2.62 2.86 2.59 2.83 2.8 ...
##  $ V7  : num  2.62 2.86 2.59 2.83 2.8 ...
##  $ V8  : num  2.62 2.87 2.6 2.84 2.8 ...
##  $ V9  : num  2.63 2.87 2.6 2.84 2.81 ...
##  $ V10 : num  2.63 2.88 2.6 2.84 2.81 ...
##  $ V11 : num  2.63 2.88 2.6 2.84 2.81 ...
##  $ V12 : num  2.63 2.89 2.61 2.85 2.82 ...
##  $ V13 : num  2.64 2.9 2.61 2.85 2.82 ...
##  $ V14 : num  2.64 2.9 2.61 2.85 2.83 ...
##  $ V15 : num  2.64 2.91 2.62 2.86 2.83 ...
##  $ V16 : num  2.65 2.92 2.62 2.86 2.84 ...
##  $ V17 : num  2.65 2.93 2.62 2.86 2.85 ...
##  $ V18 : num  2.66 2.94 2.63 2.87 2.85 ...
##  $ V19 : num  2.67 2.95 2.63 2.87 2.86 ...
##  $ V20 : num  2.67 2.96 2.64 2.88 2.87 ...
##  $ V21 : num  2.68 2.97 2.64 2.88 2.88 ...
##  $ V22 : num  2.69 2.98 2.65 2.89 2.89 ...
##  $ V23 : num  2.69 3 2.65 2.89 2.9 ...
##  $ V24 : num  2.7 3.01 2.66 2.9 2.91 ...
##  $ V25 : num  2.71 3.02 2.66 2.9 2.92 ...
##  $ V26 : num  2.71 3.03 2.67 2.91 2.93 ...
##  $ V27 : num  2.72 3.04 2.67 2.92 2.94 ...
##  $ V28 : num  2.73 3.05 2.68 2.92 2.95 ...
##  $ V29 : num  2.73 3.07 2.68 2.93 2.96 ...
##  $ V30 : num  2.74 3.08 2.69 2.93 2.97 ...
##  $ V31 : num  2.75 3.1 2.69 2.94 2.99 ...
##  $ V32 : num  2.77 3.12 2.7 2.94 3 ...
##  $ V33 : num  2.78 3.14 2.71 2.95 3.02 ...
##  $ V34 : num  2.79 3.16 2.71 2.95 3.03 ...
##  $ V35 : num  2.8 3.18 2.72 2.96 3.05 ...
##  $ V36 : num  2.81 3.2 2.72 2.96 3.06 ...
##  $ V37 : num  2.83 3.22 2.73 2.97 3.08 ...
##  $ V38 : num  2.84 3.24 2.74 2.98 3.1 ...
##  $ V39 : num  2.86 3.26 2.75 2.99 3.12 ...
##  $ V40 : num  2.88 3.28 2.77 3 3.14 ...
##  $ V41 : num  2.89 3.29 2.78 3.02 3.17 ...
##  $ V42 : num  2.91 3.3 2.79 3.03 3.18 ...
##  $ V43 : num  2.92 3.31 2.81 3.05 3.2 ...
##  $ V44 : num  2.93 3.3 2.82 3.06 3.21 ...
##  $ V45 : num  2.94 3.3 2.84 3.08 3.23 ...
##  $ V46 : num  2.95 3.29 2.85 3.1 3.24 ...
##  $ V47 : num  2.96 3.28 2.87 3.12 3.25 ...
##  $ V48 : num  2.98 3.29 2.89 3.14 3.26 ...
##  $ V49 : num  3 3.29 2.91 3.16 3.28 ...
##  $ V50 : num  3.04 3.31 2.94 3.19 3.31 ...
##  $ V51 : num  3.07 3.33 2.97 3.22 3.35 ...
##  $ V52 : num  3.12 3.36 3.01 3.26 3.39 ...
##  $ V53 : num  3.17 3.4 3.05 3.3 3.44 ...
##  $ V54 : num  3.22 3.43 3.09 3.35 3.5 ...
##  $ V55 : num  3.26 3.46 3.12 3.39 3.55 ...
##  $ V56 : num  3.3 3.49 3.15 3.43 3.61 ...
##  $ V57 : num  3.33 3.51 3.17 3.46 3.65 ...
##  $ V58 : num  3.35 3.53 3.18 3.48 3.68 ...
##  $ V59 : num  3.36 3.54 3.19 3.5 3.7 ...
##  $ V60 : num  3.37 3.55 3.19 3.51 3.72 ...
##  $ V61 : num  3.38 3.55 3.19 3.51 3.73 ...
##  $ V62 : num  3.39 3.56 3.19 3.51 3.74 ...
##  $ V63 : num  3.39 3.56 3.18 3.51 3.74 ...
##  $ V64 : num  3.39 3.56 3.18 3.51 3.74 ...
##  $ V65 : num  3.39 3.56 3.17 3.51 3.74 ...
##  $ V66 : num  3.39 3.56 3.17 3.5 3.74 ...
##  $ V67 : num  3.39 3.56 3.16 3.49 3.74 ...
##  $ V68 : num  3.39 3.55 3.15 3.48 3.73 ...
##  $ V69 : num  3.38 3.55 3.13 3.47 3.73 ...
##  $ V70 : num  3.37 3.54 3.12 3.46 3.72 ...
##  $ V71 : num  3.36 3.53 3.1 3.45 3.71 ...
##  $ V72 : num  3.35 3.52 3.09 3.43 3.69 ...
##  $ V73 : num  3.34 3.52 3.07 3.41 3.68 ...
##  $ V74 : num  3.32 3.51 3.05 3.39 3.66 ...
##  $ V75 : num  3.31 3.5 3.03 3.38 3.65 ...
##  $ V76 : num  3.29 3.49 3.02 3.35 3.63 ...
##  $ V77 : num  3.28 3.48 3 3.33 3.61 ...
##  $ V78 : num  3.26 3.47 2.98 3.31 3.59 ...
##  $ V79 : num  3.25 3.46 2.96 3.29 3.58 ...
##  $ V80 : num  3.23 3.44 2.94 3.27 3.56 ...
##  $ V81 : num  3.21 3.43 2.92 3.24 3.54 ...
##  $ V82 : num  3.19 3.42 2.9 3.22 3.52 ...
##  $ V83 : num  3.17 3.41 2.88 3.2 3.5 ...
##  $ V84 : num  3.16 3.4 2.86 3.17 3.48 ...
##  $ V85 : num  3.13 3.39 2.83 3.15 3.46 ...
##  $ V86 : num  3.11 3.38 2.81 3.12 3.44 ...
##  $ V87 : num  3.09 3.36 2.79 3.1 3.41 ...
##  $ V88 : num  3.07 3.35 2.77 3.07 3.39 ...
##  $ V89 : num  3.05 3.33 2.75 3.05 3.37 ...
##  $ V90 : num  3.02 3.32 2.73 3.02 3.34 ...
##  $ V91 : num  3 3.3 2.71 3 3.32 ...
##  $ V92 : num  2.98 3.29 2.69 2.97 3.3 ...
##  $ V93 : num  2.96 3.28 2.67 2.95 3.28 ...
##  $ V94 : num  2.94 3.27 2.65 2.93 3.26 ...
##  $ V95 : num  2.92 3.25 2.63 2.9 3.24 ...
##  $ V96 : num  2.9 3.24 2.61 2.88 3.22 ...
##  $ V97 : num  2.88 3.23 2.6 2.86 3.2 ...
##  $ V98 : num  2.86 3.21 2.58 2.84 3.18 ...
##  $ V99 : num  2.84 3.2 2.56 2.82 3.16 ...
##   [list output truncated]
names(meatspec)
##   [1] "V1"   "V2"   "V3"   "V4"   "V5"   "V6"   "V7"   "V8"   "V9"   "V10" 
##  [11] "V11"  "V12"  "V13"  "V14"  "V15"  "V16"  "V17"  "V18"  "V19"  "V20" 
##  [21] "V21"  "V22"  "V23"  "V24"  "V25"  "V26"  "V27"  "V28"  "V29"  "V30" 
##  [31] "V31"  "V32"  "V33"  "V34"  "V35"  "V36"  "V37"  "V38"  "V39"  "V40" 
##  [41] "V41"  "V42"  "V43"  "V44"  "V45"  "V46"  "V47"  "V48"  "V49"  "V50" 
##  [51] "V51"  "V52"  "V53"  "V54"  "V55"  "V56"  "V57"  "V58"  "V59"  "V60" 
##  [61] "V61"  "V62"  "V63"  "V64"  "V65"  "V66"  "V67"  "V68"  "V69"  "V70" 
##  [71] "V71"  "V72"  "V73"  "V74"  "V75"  "V76"  "V77"  "V78"  "V79"  "V80" 
##  [81] "V81"  "V82"  "V83"  "V84"  "V85"  "V86"  "V87"  "V88"  "V89"  "V90" 
##  [91] "V91"  "V92"  "V93"  "V94"  "V95"  "V96"  "V97"  "V98"  "V99"  "V100"
## [101] "fat"
model <- lm(fat~.,meatspec[1:172,])
summary(model)
## 
## Call:
## lm(formula = fat ~ ., data = meatspec[1:172, ])
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -2.09837 -0.35779  0.04555  0.38080  2.33860 
## 
## Coefficients:
##               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)      6.324      2.012   3.143 0.002439 ** 
## V1           12134.077   3659.798   3.316 0.001443 ** 
## V2          -12585.857   5971.891  -2.108 0.038605 *  
## V3           -5107.556   9390.265  -0.544 0.588200    
## V4           23880.493  17143.644   1.393 0.167977    
## V5          -40509.555  22129.359  -1.831 0.071360 .  
## V6           28469.416  19569.400   1.455 0.150134    
## V7          -20901.082  12501.639  -1.672 0.098952 .  
## V8            8369.465   7515.467   1.114 0.269193    
## V9           -1539.328   5397.505  -0.285 0.776327    
## V10           4706.267   7406.895   0.635 0.527217    
## V11           7012.943  11720.620   0.598 0.551516    
## V12          14891.444  20169.170   0.738 0.462749    
## V13         -30963.902  26186.839  -1.182 0.240983    
## V14          34338.612  22323.830   1.538 0.128444    
## V15         -22235.237  13842.268  -1.606 0.112640    
## V16          -7466.797   8558.172  -0.872 0.385890    
## V17           6716.653   6561.805   1.024 0.309500    
## V18          -2033.071   6741.330  -0.302 0.763851    
## V19           8541.212   9419.998   0.907 0.367627    
## V20          -1667.207  17300.433  -0.096 0.923500    
## V21         -31972.494  24622.615  -1.299 0.198317    
## V22          59526.389  27730.712   2.147 0.035244 *  
## V23         -49241.388  23117.226  -2.130 0.036632 *  
## V24          16184.597  16679.609   0.970 0.335180    
## V25          12077.951  10751.912   1.123 0.265081    
## V26         -12632.330   6774.573  -1.865 0.066361 .  
## V27          -6298.837   7032.334  -0.896 0.373442    
## V28          29625.988   9011.227   3.288 0.001573 ** 
## V29         -39374.835  13561.228  -2.903 0.004914 ** 
## V30          31251.427  18742.000   1.667 0.099829 .  
## V31         -27238.189  21335.756  -1.277 0.205887    
## V32          23009.543  19776.156   1.163 0.248522    
## V33          -4584.373  14572.471  -0.315 0.753995    
## V34          -5437.943  10344.728  -0.526 0.600754    
## V35          -6128.931   8762.663  -0.699 0.486564    
## V36           5599.605   6652.640   0.842 0.402776    
## V37          -5569.160   6670.198  -0.835 0.406557    
## V38             97.451   9291.480   0.010 0.991661    
## V39          36021.407  12574.711   2.865 0.005488 ** 
## V40         -54273.400  17144.384  -3.166 0.002280 ** 
## V41          52084.876  21758.024   2.394 0.019318 *  
## V42         -48458.089  23950.549  -2.023 0.046813 *  
## V43          29334.488  20232.617   1.450 0.151500    
## V44         -18282.834  13508.157  -1.353 0.180200    
## V45          22110.934   9725.348   2.274 0.026020 *  
## V46         -11735.692   6631.245  -1.770 0.081061 .  
## V47           -514.521   3800.612  -0.135 0.892696    
## V48           2551.480   6131.893   0.416 0.678592    
## V49           3707.639   8970.401   0.413 0.680618    
## V50         -25762.703  10934.783  -2.356 0.021236 *  
## V51          46844.468  15367.852   3.048 0.003233 ** 
## V52         -47783.626  18069.344  -2.644 0.010065 *  
## V53          26233.604  18822.491   1.394 0.167744    
## V54             87.825  17403.836   0.005 0.995988    
## V55          -8475.119  13232.005  -0.641 0.523908    
## V56           3488.507   7228.428   0.483 0.630858    
## V57          -1520.733   4988.093  -0.305 0.761355    
## V58           2275.175   5495.630   0.414 0.680124    
## V59          -5415.427   5721.475  -0.947 0.347099    
## V60           7152.015   4754.317   1.504 0.136935    
## V61          -4494.234   4512.937  -0.996 0.322702    
## V62           3662.045   4811.634   0.761 0.449129    
## V63          13993.987   7098.106   1.972 0.052563 .  
## V64         -23252.133   8973.839  -2.591 0.011604 *  
## V65           4373.731  10048.591   0.435 0.664695    
## V66           4580.913  10146.146   0.451 0.653011    
## V67           -837.676  10747.974  -0.078 0.938097    
## V68          -7074.425  10852.430  -0.652 0.516587    
## V69           9506.571   9739.256   0.976 0.332325    
## V70          -2765.099   9519.031  -0.290 0.772295    
## V71          -1125.135   8586.061  -0.131 0.896113    
## V72          -7295.096   7489.488  -0.974 0.333341    
## V73          17059.811   6522.093   2.616 0.010870 *  
## V74          -9889.553   6543.945  -1.511 0.135162    
## V75           -325.615   6125.973  -0.053 0.957759    
## V76            782.219   5421.002   0.144 0.885677    
## V77           8058.935   5793.416   1.391 0.168554    
## V78         -15869.978   6448.208  -2.461 0.016282 *  
## V79          21768.619   6435.678   3.382 0.001172 ** 
## V80         -28338.145   8180.874  -3.464 0.000906 ***
## V81           8523.317  10053.153   0.848 0.399384    
## V82          22319.451  12098.046   1.845 0.069226 .  
## V83         -17244.722  13991.685  -1.232 0.221829    
## V84         -18325.836  14959.964  -1.225 0.224627    
## V85          33345.457  13868.197   2.404 0.018808 *  
## V86          -7955.157  14571.278  -0.546 0.586813    
## V87          -7837.966  16141.553  -0.486 0.628762    
## V88          -1815.552  17261.928  -0.105 0.916532    
## V89            631.595  15684.751   0.040 0.967992    
## V90          -2701.955  16187.612  -0.167 0.867911    
## V91           4375.678  19400.005   0.226 0.822199    
## V92          12925.188  16456.244   0.785 0.434816    
## V93          -7441.235  12417.883  -0.599 0.550923    
## V94          -2464.532  11815.234  -0.209 0.835366    
## V95          -2090.635   9666.576  -0.216 0.829394    
## V96          10912.352   9950.716   1.097 0.276505    
## V97         -20331.405  11022.234  -1.845 0.069270 .  
## V98           3948.443   8227.133   0.480 0.632753    
## V99           6358.930   8652.372   0.735 0.464800    
## V100          -263.365   4104.463  -0.064 0.949019    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 1.074 on 71 degrees of freedom
## Multiple R-squared:  0.997,  Adjusted R-squared:  0.9928 
## F-statistic: 237.5 on 100 and 71 DF,  p-value: < 2.2e-16
# We see that the fit of this model is already 
# very good in terms of R2. How well does this 
# model do in predicting the observations in 
# the test sample? We need a measure of performance—we
# use root mean square error (RMSE): 

rmse <- function(x,y) sqrt(mean((x-y)^2))
rmse(model$fit,meatspec$fat[1:172])
## [1] 0.6903167
rmse(predict(model,meatspec[173:215,]),meatspec$fat[173:215])
## [1] 3.814
# We see that the performance is much worse for the test
# sample. This is not unusual, as the fit to the data we 
# have almost always gives an overoptimistic sense of how 
# well the model will do with future data. In this case,
# the actual error is about five times greater than the
# model itself suggests. 
# Now, it is quite likely that not all 100 predictors are
# necessary to make a good prediction. In fact, some of 
# them might just be adding noise to the prediction and 
# we could improve matters by eliminating some of them.
# We use the default stepwise model selection:
model2 <- step(model)
## Start:  AIC=74.51
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V9 + V10 + V11 + 
##     V12 + V13 + V14 + V15 + V16 + V17 + V18 + V19 + V20 + V21 + 
##     V22 + V23 + V24 + V25 + V26 + V27 + V28 + V29 + V30 + V31 + 
##     V32 + V33 + V34 + V35 + V36 + V37 + V38 + V39 + V40 + V41 + 
##     V42 + V43 + V44 + V45 + V46 + V47 + V48 + V49 + V50 + V51 + 
##     V52 + V53 + V54 + V55 + V56 + V57 + V58 + V59 + V60 + V61 + 
##     V62 + V63 + V64 + V65 + V66 + V67 + V68 + V69 + V70 + V71 + 
##     V72 + V73 + V74 + V75 + V76 + V77 + V78 + V79 + V80 + V81 + 
##     V82 + V83 + V84 + V85 + V86 + V87 + V88 + V89 + V90 + V91 + 
##     V92 + V93 + V94 + V95 + V96 + V97 + V98 + V99 + V100
## 
##        Df Sum of Sq    RSS    AIC
## - V54   1    0.0000 81.964 72.512
## - V38   1    0.0001 81.965 72.512
## - V89   1    0.0019 81.966 72.516
## - V75   1    0.0033 81.968 72.519
## - V100  1    0.0048 81.969 72.522
## - V67   1    0.0070 81.971 72.527
## - V20   1    0.0107 81.975 72.534
## - V88   1    0.0128 81.977 72.539
## - V71   1    0.0198 81.984 72.554
## - V47   1    0.0212 81.986 72.556
## - V76   1    0.0240 81.988 72.562
## - V90   1    0.0322 81.997 72.579
## - V94   1    0.0502 82.015 72.617
## - V95   1    0.0540 82.018 72.625
## - V91   1    0.0587 82.023 72.635
## - V9    1    0.0939 82.058 72.709
## - V70   1    0.0974 82.062 72.716
## - V18   1    0.1050 82.069 72.732
## - V57   1    0.1073 82.072 72.737
## - V33   1    0.1143 82.079 72.752
## - V49   1    0.1972 82.162 72.925
## - V58   1    0.1979 82.162 72.927
## - V48   1    0.1999 82.164 72.931
## - V65   1    0.2187 82.183 72.970
## - V66   1    0.2353 82.200 73.005
## - V98   1    0.2659 82.230 73.069
## - V56   1    0.2689 82.233 73.075
## - V87   1    0.2722 82.237 73.082
## - V34   1    0.3190 82.283 73.180
## - V3    1    0.3415 82.306 73.227
## - V86   1    0.3441 82.308 73.233
## - V11   1    0.4133 82.378 73.377
## - V93   1    0.4145 82.379 73.380
## - V10   1    0.4661 82.430 73.487
## - V55   1    0.4736 82.438 73.503
## - V68   1    0.4906 82.455 73.538
## - V35   1    0.5648 82.529 73.693
## - V99   1    0.6235 82.588 73.815
## - V12   1    0.6293 82.594 73.828
## - V62   1    0.6687 82.633 73.910
## - V92   1    0.7122 82.677 74.000
## - V37   1    0.8048 82.769 74.192
## - V36   1    0.8179 82.782 74.220
## - V81   1    0.8298 82.794 74.245
## - V16   1    0.8788 82.843 74.346
## - V27   1    0.9262 82.891 74.445
## - V19   1    0.9491 82.913 74.492
## <none>              81.964 74.512
## - V59   1    1.0342 82.999 74.669
## - V24   1    1.0869 83.051 74.778
## - V72   1    1.0953 83.060 74.795
## - V69   1    1.0999 83.064 74.805
## - V61   1    1.1449 83.109 74.898
## - V17   1    1.2096 83.174 75.032
## - V96   1    1.3883 83.353 75.401
## - V8    1    1.4317 83.396 75.490
## - V25   1    1.4567 83.421 75.542
## - V32   1    1.5628 83.527 75.761
## - V13   1    1.6140 83.578 75.866
## - V84   1    1.7323 83.697 76.109
## - V83   1    1.7536 83.718 76.153
## - V31   1    1.8815 83.846 76.416
## - V21   1    1.9465 83.911 76.549
## - V44   1    2.1148 84.079 76.893
## - V77   1    2.2338 84.198 77.137
## - V4    1    2.2400 84.204 77.149
## - V53   1    2.2425 84.207 77.155
## - V43   1    2.4267 84.391 77.530
## - V6    1    2.4433 84.408 77.564
## - V60   1    2.6124 84.577 77.909
## - V74   1    2.6366 84.601 77.958
## - V14   1    2.7315 84.696 78.150
## - V15   1    2.9788 84.943 78.652
## - V30   1    3.2098 85.174 79.119
## - V7    1    3.2268 85.191 79.153
## - V46   1    3.6157 85.580 79.937
## - V5    1    3.8685 85.833 80.444
## - V97   1    3.9279 85.892 80.563
## - V82   1    3.9292 85.894 80.566
## - V26   1    4.0139 85.978 80.735
## - V63   1    4.4871 86.451 81.679
## - V42   1    4.7257 86.690 82.153
## - V2    1    5.1275 87.092 82.949
## - V23   1    5.2379 87.202 83.167
## - V22   1    5.3194 87.284 83.327
## - V45   1    5.9672 87.932 84.599
## - V50   1    6.4081 88.372 85.459
## - V41   1    6.6153 88.580 85.862
## - V85   1    6.6742 88.639 85.977
## - V78   1    6.9926 88.957 86.593
## - V64   1    7.7506 89.715 88.053
## - V73   1    7.8984 89.863 88.336
## - V52   1    8.0731 90.037 88.670
## - V39   1    9.4731 91.437 91.324
## - V29   1    9.7321 91.696 91.810
## - V51   1   10.7265 92.691 93.665
## - V40   1   11.5690 93.533 95.222
## - V28   1   12.4780 94.442 96.885
## - V1    1   12.6901 94.655 97.271
## - V79   1   13.2081 95.172 98.210
## - V80   1   13.8519 95.816 99.369
## 
## Step:  AIC=72.51
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V9 + V10 + V11 + 
##     V12 + V13 + V14 + V15 + V16 + V17 + V18 + V19 + V20 + V21 + 
##     V22 + V23 + V24 + V25 + V26 + V27 + V28 + V29 + V30 + V31 + 
##     V32 + V33 + V34 + V35 + V36 + V37 + V38 + V39 + V40 + V41 + 
##     V42 + V43 + V44 + V45 + V46 + V47 + V48 + V49 + V50 + V51 + 
##     V52 + V53 + V55 + V56 + V57 + V58 + V59 + V60 + V61 + V62 + 
##     V63 + V64 + V65 + V66 + V67 + V68 + V69 + V70 + V71 + V72 + 
##     V73 + V74 + V75 + V76 + V77 + V78 + V79 + V80 + V81 + V82 + 
##     V83 + V84 + V85 + V86 + V87 + V88 + V89 + V90 + V91 + V92 + 
##     V93 + V94 + V95 + V96 + V97 + V98 + V99 + V100
## 
##        Df Sum of Sq    RSS     AIC
## - V38   1    0.0001 81.965  70.512
## - V89   1    0.0019 81.966  70.516
## - V75   1    0.0035 81.968  70.519
## - V100  1    0.0047 81.969  70.522
## - V67   1    0.0076 81.972  70.528
## - V20   1    0.0107 81.975  70.534
## - V88   1    0.0131 81.978  70.539
## - V71   1    0.0201 81.984  70.554
## - V47   1    0.0216 81.986  70.557
## - V76   1    0.0243 81.989  70.563
## - V90   1    0.0322 81.997  70.580
## - V94   1    0.0504 82.015  70.618
## - V95   1    0.0552 82.020  70.628
## - V91   1    0.0587 82.023  70.635
## - V9    1    0.0939 82.058  70.709
## - V70   1    0.0989 82.063  70.719
## - V18   1    0.1050 82.069  70.732
## - V33   1    0.1146 82.079  70.752
## - V57   1    0.1235 82.088  70.771
## - V49   1    0.2012 82.166  70.934
## - V58   1    0.2141 82.179  70.961
## - V48   1    0.2208 82.185  70.975
## - V65   1    0.2279 82.192  70.990
## - V66   1    0.2357 82.200  71.006
## - V98   1    0.2666 82.231  71.071
## - V87   1    0.2740 82.238  71.086
## - V34   1    0.3267 82.291  71.196
## - V3    1    0.3416 82.306  71.227
## - V86   1    0.3533 82.318  71.252
## - V93   1    0.4165 82.381  71.384
## - V11   1    0.4243 82.389  71.400
## - V10   1    0.4786 82.443  71.513
## - V68   1    0.5216 82.486  71.603
## - V56   1    0.5245 82.489  71.609
## - V35   1    0.5726 82.537  71.710
## - V99   1    0.6251 82.590  71.819
## - V12   1    0.6552 82.620  71.882
## - V62   1    0.6719 82.636  71.916
## - V92   1    0.7164 82.681  72.009
## - V36   1    0.8229 82.787  72.230
## - V37   1    0.8348 82.799  72.255
## - V81   1    0.8712 82.836  72.331
## - V16   1    0.8799 82.844  72.349
## - V27   1    0.9321 82.896  72.457
## - V19   1    0.9498 82.914  72.494
## <none>              81.964  72.512
## - V59   1    1.0844 83.049  72.773
## - V72   1    1.0953 83.060  72.795
## - V24   1    1.1239 83.088  72.854
## - V69   1    1.1381 83.103  72.884
## - V61   1    1.1535 83.118  72.916
## - V17   1    1.2141 83.178  73.041
## - V96   1    1.3968 83.361  73.419
## - V8    1    1.4323 83.397  73.492
## - V25   1    1.4567 83.421  73.542
## - V32   1    1.5629 83.527  73.761
## - V13   1    1.6700 83.634  73.981
## - V83   1    1.8674 83.832  74.387
## - V31   1    1.8897 83.854  74.432
## - V21   1    1.9874 83.952  74.633
## - V84   1    2.0185 83.983  74.697
## - V44   1    2.1226 84.087  74.910
## - V4    1    2.2570 84.221  75.184
## - V77   1    2.2666 84.231  75.204
## - V43   1    2.4424 84.407  75.563
## - V6    1    2.4437 84.408  75.565
## - V60   1    2.7257 84.690  76.139
## - V74   1    2.7516 84.716  76.191
## - V55   1    2.7969 84.761  76.283
## - V14   1    2.8230 84.787  76.336
## - V15   1    3.0649 85.029  76.826
## - V7    1    3.2288 85.193  77.157
## - V30   1    3.2705 85.235  77.242
## - V5    1    3.8742 85.839  78.456
## - V46   1    3.8934 85.858  78.494
## - V97   1    3.9367 85.901  78.581
## - V26   1    4.0179 85.982  78.743
## - V82   1    4.0803 86.045  78.868
## - V63   1    4.4945 86.459  79.694
## - V42   1    4.9341 86.899  80.566
## - V2    1    5.1467 87.111  80.987
## - V22   1    5.7115 87.676  82.098
## - V23   1    5.8132 87.778  82.298
## - V45   1    5.9677 87.932  82.600
## - V50   1    6.8210 88.785  84.261
## - V78   1    6.9928 88.957  84.594
## - V41   1    7.0263 88.991  84.658
## - V85   1    7.5581 89.523  85.683
## - V64   1    8.0604 90.025  86.646
## - V73   1    8.1744 90.139  86.863
## - V39   1    9.8990 91.863  90.123
## - V29   1    9.9135 91.878  90.150
## - V53   1   11.0348 92.999  92.237
## - V40   1   12.1604 94.125  94.306
## - V28   1   12.5323 94.497  94.984
## - V1    1   13.1906 95.155  96.178
## - V79   1   13.2682 95.233  96.318
## - V51   1   14.1805 96.145  97.958
## - V80   1   14.3616 96.326  98.282
## - V52   1   15.3320 97.296 100.006
## 
## Step:  AIC=70.51
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V9 + V10 + V11 + 
##     V12 + V13 + V14 + V15 + V16 + V17 + V18 + V19 + V20 + V21 + 
##     V22 + V23 + V24 + V25 + V26 + V27 + V28 + V29 + V30 + V31 + 
##     V32 + V33 + V34 + V35 + V36 + V37 + V39 + V40 + V41 + V42 + 
##     V43 + V44 + V45 + V46 + V47 + V48 + V49 + V50 + V51 + V52 + 
##     V53 + V55 + V56 + V57 + V58 + V59 + V60 + V61 + V62 + V63 + 
##     V64 + V65 + V66 + V67 + V68 + V69 + V70 + V71 + V72 + V73 + 
##     V74 + V75 + V76 + V77 + V78 + V79 + V80 + V81 + V82 + V83 + 
##     V84 + V85 + V86 + V87 + V88 + V89 + V90 + V91 + V92 + V93 + 
##     V94 + V95 + V96 + V97 + V98 + V99 + V100
## 
##        Df Sum of Sq     RSS     AIC
## - V89   1    0.0019  81.966  68.516
## - V75   1    0.0034  81.968  68.519
## - V100  1    0.0046  81.969  68.522
## - V67   1    0.0077  81.972  68.528
## - V20   1    0.0106  81.975  68.534
## - V88   1    0.0130  81.978  68.540
## - V71   1    0.0205  81.985  68.555
## - V47   1    0.0217  81.986  68.558
## - V76   1    0.0249  81.989  68.565
## - V90   1    0.0332  81.998  68.582
## - V94   1    0.0503  82.015  68.618
## - V95   1    0.0551  82.020  68.628
## - V91   1    0.0599  82.024  68.638
## - V9    1    0.0942  82.059  68.710
## - V70   1    0.0997  82.064  68.721
## - V18   1    0.1049  82.069  68.732
## - V33   1    0.1151  82.080  68.754
## - V57   1    0.1249  82.089  68.774
## - V49   1    0.2104  82.175  68.953
## - V58   1    0.2238  82.188  68.981
## - V65   1    0.2329  82.197  69.000
## - V66   1    0.2426  82.207  69.021
## - V48   1    0.2488  82.213  69.034
## - V98   1    0.2708  82.235  69.080
## - V87   1    0.2741  82.239  69.086
## - V34   1    0.3286  82.293  69.200
## - V3    1    0.3416  82.306  69.228
## - V86   1    0.3535  82.318  69.252
## - V93   1    0.4164  82.381  69.384
## - V11   1    0.4269  82.391  69.406
## - V10   1    0.4794  82.444  69.515
## - V68   1    0.5218  82.486  69.604
## - V56   1    0.5310  82.496  69.623
## - V35   1    0.5752  82.540  69.715
## - V99   1    0.6271  82.592  69.823
## - V12   1    0.6560  82.621  69.883
## - V62   1    0.6757  82.640  69.924
## - V92   1    0.7228  82.687  70.022
## - V36   1    0.8432  82.808  70.273
## - V81   1    0.8739  82.838  70.336
## - V16   1    0.9059  82.870  70.403
## - V27   1    0.9334  82.898  70.460
## - V19   1    0.9534  82.918  70.501
## <none>               81.965  70.512
## - V59   1    1.1038  83.068  70.813
## - V37   1    1.1046  83.069  70.815
## - V24   1    1.1282  83.093  70.864
## - V72   1    1.1391  83.104  70.886
## - V69   1    1.1403  83.105  70.889
## - V61   1    1.1550  83.120  70.919
## - V17   1    1.2857  83.250  71.189
## - V8    1    1.4347  83.399  71.497
## - V25   1    1.4594  83.424  71.548
## - V96   1    1.5537  83.518  71.742
## - V32   1    1.5943  83.559  71.826
## - V13   1    1.6718  83.636  71.985
## - V83   1    1.8783  83.843  72.409
## - V31   1    1.9178  83.882  72.490
## - V21   1    1.9989  83.963  72.657
## - V84   1    2.1479  84.112  72.961
## - V77   1    2.2688  84.233  73.209
## - V4    1    2.2692  84.234  73.209
## - V6    1    2.4470  84.412  73.572
## - V44   1    2.5258  84.490  73.733
## - V60   1    2.7256  84.690  74.139
## - V43   1    2.8040  84.769  74.298
## - V14   1    2.8229  84.787  74.336
## - V55   1    2.8611  84.826  74.414
## - V74   1    2.9463  84.911  74.586
## - V15   1    3.0680  85.033  74.833
## - V7    1    3.2436  85.208  75.188
## - V30   1    3.2818  85.246  75.265
## - V5    1    3.8888  85.853  76.485
## - V46   1    3.8942  85.859  76.496
## - V26   1    4.0203  85.985  76.748
## - V82   1    4.1207  86.085  76.949
## - V63   1    4.4984  86.463  77.702
## - V97   1    4.5127  86.477  77.730
## - V2    1    5.2677  87.232  79.226
## - V42   1    5.5005  87.465  79.684
## - V22   1    5.7384  87.703  80.151
## - V23   1    5.8296  87.794  80.330
## - V45   1    6.4226  88.387  81.488
## - V50   1    6.8406  88.805  82.299
## - V78   1    6.9943  88.959  82.597
## - V41   1    7.4652  89.430  83.505
## - V85   1    7.7699  89.734  84.090
## - V64   1    8.0886  90.053  84.700
## - V73   1    8.9320  90.897  86.303
## - V29   1    9.9348  91.899  88.190
## - V53   1   11.0740  93.039  90.309
## - V28   1   12.6219  94.586  93.147
## - V40   1   13.0363  95.001  93.899
## - V79   1   13.2892  95.254  94.357
## - V1    1   13.8603  95.825  95.385
## - V51   1   14.2041  96.169  96.001
## - V80   1   14.3801  96.345  96.315
## - V52   1   15.3320  97.297  98.006
## - V39   1   18.9076 100.872 104.214
## 
## Step:  AIC=68.52
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V9 + V10 + V11 + 
##     V12 + V13 + V14 + V15 + V16 + V17 + V18 + V19 + V20 + V21 + 
##     V22 + V23 + V24 + V25 + V26 + V27 + V28 + V29 + V30 + V31 + 
##     V32 + V33 + V34 + V35 + V36 + V37 + V39 + V40 + V41 + V42 + 
##     V43 + V44 + V45 + V46 + V47 + V48 + V49 + V50 + V51 + V52 + 
##     V53 + V55 + V56 + V57 + V58 + V59 + V60 + V61 + V62 + V63 + 
##     V64 + V65 + V66 + V67 + V68 + V69 + V70 + V71 + V72 + V73 + 
##     V74 + V75 + V76 + V77 + V78 + V79 + V80 + V81 + V82 + V83 + 
##     V84 + V85 + V86 + V87 + V88 + V90 + V91 + V92 + V93 + V94 + 
##     V95 + V96 + V97 + V98 + V99 + V100
## 
##        Df Sum of Sq     RSS     AIC
## - V100  1    0.0032  81.970  66.523
## - V67   1    0.0065  81.973  66.530
## - V75   1    0.0076  81.974  66.532
## - V20   1    0.0105  81.977  66.538
## - V88   1    0.0174  81.984  66.553
## - V47   1    0.0224  81.989  66.563
## - V71   1    0.0256  81.992  66.570
## - V76   1    0.0353  82.002  66.590
## - V90   1    0.0410  82.007  66.602
## - V94   1    0.0490  82.015  66.619
## - V91   1    0.0581  82.025  66.638
## - V95   1    0.0598  82.026  66.642
## - V9    1    0.0967  82.063  66.719
## - V70   1    0.1013  82.068  66.729
## - V18   1    0.1059  82.072  66.738
## - V33   1    0.1137  82.080  66.755
## - V57   1    0.1278  82.094  66.784
## - V49   1    0.2210  82.188  66.980
## - V58   1    0.2245  82.191  66.987
## - V48   1    0.2468  82.213  67.034
## - V66   1    0.2525  82.219  67.045
## - V98   1    0.2699  82.236  67.082
## - V65   1    0.2801  82.247  67.103
## - V34   1    0.3268  82.293  67.201
## - V87   1    0.3431  82.310  67.235
## - V86   1    0.3538  82.320  67.257
## - V3    1    0.3581  82.325  67.266
## - V93   1    0.4174  82.384  67.390
## - V11   1    0.4307  82.397  67.418
## - V68   1    0.5199  82.486  67.604
## - V10   1    0.5207  82.487  67.606
## - V56   1    0.5731  82.540  67.715
## - V35   1    0.6351  82.602  67.844
## - V99   1    0.6554  82.622  67.886
## - V12   1    0.6681  82.635  67.913
## - V92   1    0.7303  82.697  68.042
## - V62   1    0.7332  82.700  68.048
## - V81   1    0.9059  82.872  68.407
## - V36   1    0.9127  82.879  68.421
## - V16   1    0.9207  82.887  68.438
## - V27   1    0.9317  82.898  68.460
## - V19   1    0.9523  82.919  68.503
## <none>               81.966  68.516
## - V72   1    1.1671  83.134  68.948
## - V59   1    1.1683  83.135  68.951
## - V37   1    1.1761  83.143  68.967
## - V24   1    1.1796  83.146  68.974
## - V69   1    1.1914  83.158  68.998
## - V17   1    1.2867  83.253  69.195
## - V61   1    1.3244  83.291  69.273
## - V8    1    1.4546  83.421  69.542
## - V25   1    1.5069  83.473  69.650
## - V96   1    1.5562  83.523  69.751
## - V32   1    1.6299  83.596  69.903
## - V13   1    1.6772  83.644  70.000
## - V31   1    1.9230  83.890  70.505
## - V83   1    1.9877  83.954  70.638
## - V21   1    2.0072  83.974  70.678
## - V84   1    2.2039  84.170  71.080
## - V4    1    2.2676  84.234  71.210
## - V77   1    2.3346  84.301  71.347
## - V6    1    2.4485  84.415  71.579
## - V44   1    2.5488  84.515  71.783
## - V14   1    2.8672  84.834  72.430
## - V43   1    2.8852  84.852  72.467
## - V60   1    2.9567  84.923  72.611
## - V55   1    2.9683  84.935  72.635
## - V74   1    3.0512  85.018  72.803
## - V15   1    3.0980  85.064  72.897
## - V7    1    3.2672  85.234  73.239
## - V30   1    3.2860  85.253  73.277
## - V5    1    3.8927  85.859  74.497
## - V26   1    4.0230  85.990  74.758
## - V46   1    4.0626  86.029  74.837
## - V82   1    4.1212  86.088  74.954
## - V63   1    4.4998  86.466  75.709
## - V97   1    4.6092  86.576  75.926
## - V2    1    5.3271  87.294  77.347
## - V42   1    5.5483  87.515  77.782
## - V22   1    5.8074  87.774  78.290
## - V23   1    5.9365  87.903  78.543
## - V45   1    6.6466  88.613  79.927
## - V50   1    6.8802  88.847  80.380
## - V41   1    7.4965  89.463  81.569
## - V78   1    7.6168  89.583  81.800
## - V85   1    7.7755  89.742  82.104
## - V64   1    8.2128  90.179  82.941
## - V73   1    8.9331  90.900  84.309
## - V29   1    9.9482  91.915  86.219
## - V53   1   11.2189  93.185  88.581
## - V28   1   12.6379  94.604  91.180
## - V40   1   13.0617  95.028  91.949
## - V79   1   13.4159  95.382  92.589
## - V1    1   14.2044  96.171  94.005
## - V51   1   14.2098  96.176  94.014
## - V80   1   15.0325  96.999  95.480
## - V52   1   15.4047  97.371  96.138
## - V39   1   19.0264 100.993 102.420
## 
## Step:  AIC=66.52
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V9 + V10 + V11 + 
##     V12 + V13 + V14 + V15 + V16 + V17 + V18 + V19 + V20 + V21 + 
##     V22 + V23 + V24 + V25 + V26 + V27 + V28 + V29 + V30 + V31 + 
##     V32 + V33 + V34 + V35 + V36 + V37 + V39 + V40 + V41 + V42 + 
##     V43 + V44 + V45 + V46 + V47 + V48 + V49 + V50 + V51 + V52 + 
##     V53 + V55 + V56 + V57 + V58 + V59 + V60 + V61 + V62 + V63 + 
##     V64 + V65 + V66 + V67 + V68 + V69 + V70 + V71 + V72 + V73 + 
##     V74 + V75 + V76 + V77 + V78 + V79 + V80 + V81 + V82 + V83 + 
##     V84 + V85 + V86 + V87 + V88 + V90 + V91 + V92 + V93 + V94 + 
##     V95 + V96 + V97 + V98 + V99
## 
##        Df Sum of Sq     RSS     AIC
## - V67   1    0.0064  81.976  64.537
## - V75   1    0.0093  81.979  64.543
## - V20   1    0.0119  81.982  64.548
## - V88   1    0.0184  81.988  64.562
## - V47   1    0.0253  81.995  64.576
## - V71   1    0.0254  81.995  64.576
## - V76   1    0.0414  82.011  64.610
## - V90   1    0.0418  82.012  64.611
## - V94   1    0.0470  82.017  64.622
## - V91   1    0.0608  82.030  64.651
## - V95   1    0.0627  82.032  64.655
## - V9    1    0.0966  82.066  64.726
## - V70   1    0.0990  82.069  64.731
## - V18   1    0.1084  82.078  64.750
## - V33   1    0.1108  82.081  64.755
## - V57   1    0.1246  82.094  64.784
## - V58   1    0.2213  82.191  64.987
## - V49   1    0.2345  82.204  65.014
## - V48   1    0.2450  82.215  65.036
## - V66   1    0.2564  82.226  65.060
## - V65   1    0.2781  82.248  65.106
## - V34   1    0.3344  82.304  65.223
## - V87   1    0.3402  82.310  65.235
## - V98   1    0.3651  82.335  65.287
## - V86   1    0.3670  82.337  65.291
## - V3    1    0.3772  82.347  65.313
## - V93   1    0.4222  82.392  65.407
## - V11   1    0.4533  82.423  65.472
## - V68   1    0.5173  82.487  65.605
## - V10   1    0.5192  82.489  65.609
## - V56   1    0.5706  82.540  65.716
## - V35   1    0.6328  82.602  65.846
## - V12   1    0.6963  82.666  65.978
## - V92   1    0.7275  82.697  66.043
## - V62   1    0.7300  82.700  66.048
## - V81   1    0.9030  82.873  66.408
## - V36   1    0.9113  82.881  66.425
## - V16   1    0.9197  82.889  66.442
## - V27   1    0.9385  82.908  66.481
## <none>               81.970  66.523
## - V19   1    0.9780  82.948  66.563
## - V59   1    1.1683  83.138  66.957
## - V72   1    1.1709  83.141  66.963
## - V37   1    1.1740  83.144  66.969
## - V24   1    1.1783  83.148  66.978
## - V69   1    1.1988  83.168  67.020
## - V17   1    1.2957  83.265  67.221
## - V61   1    1.4040  83.374  67.444
## - V8    1    1.4556  83.425  67.551
## - V25   1    1.5147  83.484  67.672
## - V96   1    1.5666  83.536  67.779
## - V32   1    1.6269  83.597  67.904
## - V13   1    1.8338  83.804  68.329
## - V31   1    1.9222  83.892  68.510
## - V21   1    2.0181  83.988  68.706
## - V83   1    2.0446  84.014  68.761
## - V84   1    2.2015  84.171  69.082
## - V4    1    2.2810  84.251  69.244
## - V6    1    2.4472  84.417  69.583
## - V44   1    2.5619  84.532  69.817
## - V77   1    2.8580  84.828  70.418
## - V55   1    2.9724  84.942  70.650
## - V43   1    3.0050  84.975  70.716
## - V60   1    3.0424  85.012  70.792
## - V74   1    3.0666  85.036  70.840
## - V14   1    3.0944  85.064  70.897
## - V15   1    3.1758  85.146  71.061
## - V7    1    3.2665  85.236  71.244
## - V30   1    3.2861  85.256  71.284
## - V5    1    3.8924  85.862  72.503
## - V99   1    3.9454  85.915  72.609
## - V26   1    4.0935  86.063  72.905
## - V46   1    4.1553  86.125  73.029
## - V82   1    4.2376  86.207  73.193
## - V63   1    4.5671  86.537  73.849
## - V97   1    4.6060  86.576  73.926
## - V2    1    5.4522  87.422  75.599
## - V42   1    5.7048  87.674  76.095
## - V22   1    5.8885  87.858  76.456
## - V23   1    5.9912  87.961  76.657
## - V45   1    6.6907  88.660  78.019
## - V50   1    6.9116  88.881  78.447
## - V41   1    7.5028  89.472  79.587
## - V85   1    7.8119  89.782  80.180
## - V64   1    8.4222  90.392  81.346
## - V78   1    8.6146  90.584  81.711
## - V73   1    8.9705  90.940  82.386
## - V29   1    9.9820  91.952  84.288
## - V53   1   11.2851  93.255  86.709
## - V28   1   12.6356  94.605  89.182
## - V40   1   13.1117  95.081  90.045
## - V79   1   13.4182  95.388  90.599
## - V1    1   14.2357  96.205  92.066
## - V51   1   14.5657  96.535  92.655
## - V80   1   15.0418  97.011  93.502
## - V52   1   15.4249  97.395  94.179
## - V39   1   19.0886 101.058 100.531
## 
## Step:  AIC=64.54
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V9 + V10 + V11 + 
##     V12 + V13 + V14 + V15 + V16 + V17 + V18 + V19 + V20 + V21 + 
##     V22 + V23 + V24 + V25 + V26 + V27 + V28 + V29 + V30 + V31 + 
##     V32 + V33 + V34 + V35 + V36 + V37 + V39 + V40 + V41 + V42 + 
##     V43 + V44 + V45 + V46 + V47 + V48 + V49 + V50 + V51 + V52 + 
##     V53 + V55 + V56 + V57 + V58 + V59 + V60 + V61 + V62 + V63 + 
##     V64 + V65 + V66 + V68 + V69 + V70 + V71 + V72 + V73 + V74 + 
##     V75 + V76 + V77 + V78 + V79 + V80 + V81 + V82 + V83 + V84 + 
##     V85 + V86 + V87 + V88 + V90 + V91 + V92 + V93 + V94 + V95 + 
##     V96 + V97 + V98 + V99
## 
##        Df Sum of Sq     RSS    AIC
## - V75   1    0.0097  81.986 62.557
## - V71   1    0.0193  81.995 62.577
## - V20   1    0.0208  81.997 62.580
## - V88   1    0.0239  82.000 62.587
## - V47   1    0.0292  82.005 62.598
## - V76   1    0.0363  82.012 62.613
## - V90   1    0.0369  82.013 62.614
## - V94   1    0.0493  82.025 62.640
## - V91   1    0.0571  82.033 62.656
## - V95   1    0.0657  82.042 62.674
## - V9    1    0.1024  82.079 62.751
## - V18   1    0.1121  82.088 62.772
## - V33   1    0.1123  82.088 62.772
## - V70   1    0.1281  82.104 62.805
## - V57   1    0.1483  82.124 62.847
## - V49   1    0.2306  82.207 63.020
## - V48   1    0.3029  82.279 63.171
## - V58   1    0.3078  82.284 63.181
## - V34   1    0.3307  82.307 63.229
## - V87   1    0.3361  82.312 63.240
## - V98   1    0.3637  82.340 63.298
## - V86   1    0.3638  82.340 63.298
## - V3    1    0.3747  82.351 63.321
## - V65   1    0.4047  82.381 63.384
## - V93   1    0.4175  82.394 63.410
## - V11   1    0.4484  82.425 63.475
## - V10   1    0.5228  82.499 63.630
## - V66   1    0.5945  82.571 63.779
## - V35   1    0.6267  82.603 63.847
## - V56   1    0.6558  82.632 63.907
## - V12   1    0.6917  82.668 63.982
## - V62   1    0.7305  82.707 64.062
## - V92   1    0.7366  82.713 64.075
## - V36   1    0.9086  82.885 64.433
## - V16   1    0.9160  82.892 64.448
## - V27   1    0.9359  82.912 64.489
## <none>               81.976 64.537
## - V81   1    1.0040  82.980 64.630
## - V19   1    1.0305  83.007 64.685
## - V24   1    1.2014  83.178 65.039
## - V37   1    1.2389  83.215 65.116
## - V72   1    1.3042  83.280 65.251
## - V17   1    1.4435  83.420 65.539
## - V8    1    1.4622  83.438 65.577
## - V61   1    1.5450  83.521 65.748
## - V69   1    1.5712  83.547 65.802
## - V59   1    1.5767  83.553 65.813
## - V96   1    1.5961  83.572 65.853
## - V32   1    1.6210  83.597 65.904
## - V25   1    1.7143  83.690 66.096
## - V68   1    1.7741  83.750 66.219
## - V13   1    1.8280  83.804 66.330
## - V31   1    1.9166  83.893 66.512
## - V21   1    2.1750  84.151 67.041
## - V4    1    2.3039  84.280 67.304
## - V83   1    2.3469  84.323 67.392
## - V84   1    2.4343  84.410 67.570
## - V6    1    2.4868  84.463 67.677
## - V44   1    2.5757  84.552 67.858
## - V77   1    2.8657  84.842 68.447
## - V43   1    3.0123  84.988 68.744
## - V14   1    3.0954  85.072 68.912
## - V55   1    3.1324  85.109 68.986
## - V15   1    3.1957  85.172 69.114
## - V74   1    3.2504  85.227 69.225
## - V30   1    3.2821  85.258 69.289
## - V7    1    3.2991  85.275 69.323
## - V60   1    3.4256  85.402 69.578
## - V5    1    3.9241  85.900 70.579
## - V99   1    4.1102  86.086 70.951
## - V46   1    4.2509  86.227 71.232
## - V26   1    4.2893  86.265 71.309
## - V63   1    4.6199  86.596 71.967
## - V97   1    4.6640  86.640 72.054
## - V82   1    4.6954  86.672 72.117
## - V2    1    5.5520  87.528 73.808
## - V42   1    5.7647  87.741 74.225
## - V23   1    6.2460  88.222 75.166
## - V22   1    6.2777  88.254 75.228
## - V50   1    6.9412  88.917 76.517
## - V45   1    7.0149  88.991 76.659
## - V41   1    7.5265  89.503 77.645
## - V85   1    7.8470  89.823 78.260
## - V64   1    8.5874  90.563 79.672
## - V78   1    8.6093  90.585 79.713
## - V73   1    8.9812  90.957 80.418
## - V29   1    9.9986  91.975 82.331
## - V53   1   11.2919  93.268 84.733
## - V28   1   12.8147  94.791 87.519
## - V40   1   13.1137  95.090 88.060
## - V79   1   13.6048  95.581 88.946
## - V1    1   14.2484  96.225 90.101
## - V80   1   15.0970  97.073 91.611
## - V51   1   15.1825  97.159 91.762
## - V52   1   15.5837  97.560 92.471
## - V39   1   19.2152 101.191 98.757
## 
## Step:  AIC=62.56
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V9 + V10 + V11 + 
##     V12 + V13 + V14 + V15 + V16 + V17 + V18 + V19 + V20 + V21 + 
##     V22 + V23 + V24 + V25 + V26 + V27 + V28 + V29 + V30 + V31 + 
##     V32 + V33 + V34 + V35 + V36 + V37 + V39 + V40 + V41 + V42 + 
##     V43 + V44 + V45 + V46 + V47 + V48 + V49 + V50 + V51 + V52 + 
##     V53 + V55 + V56 + V57 + V58 + V59 + V60 + V61 + V62 + V63 + 
##     V64 + V65 + V66 + V68 + V69 + V70 + V71 + V72 + V73 + V74 + 
##     V76 + V77 + V78 + V79 + V80 + V81 + V82 + V83 + V84 + V85 + 
##     V86 + V87 + V88 + V90 + V91 + V92 + V93 + V94 + V95 + V96 + 
##     V97 + V98 + V99
## 
##        Df Sum of Sq     RSS    AIC
## - V20   1    0.0165  82.002 60.592
## - V88   1    0.0239  82.010 60.607
## - V47   1    0.0255  82.011 60.611
## - V71   1    0.0268  82.013 60.613
## - V76   1    0.0270  82.013 60.614
## - V94   1    0.0405  82.026 60.642
## - V90   1    0.0474  82.033 60.656
## - V91   1    0.0725  82.058 60.709
## - V95   1    0.0732  82.059 60.710
## - V9    1    0.0965  82.082 60.759
## - V18   1    0.1061  82.092 60.779
## - V33   1    0.1113  82.097 60.790
## - V70   1    0.1372  82.123 60.844
## - V57   1    0.1520  82.138 60.876
## - V49   1    0.2571  82.243 61.096
## - V48   1    0.2974  82.283 61.180
## - V87   1    0.3296  82.315 61.247
## - V58   1    0.3340  82.320 61.256
## - V34   1    0.3655  82.351 61.322
## - V86   1    0.3668  82.353 61.325
## - V98   1    0.3687  82.355 61.329
## - V3    1    0.3753  82.361 61.342
## - V65   1    0.4067  82.393 61.408
## - V11   1    0.4559  82.442 61.511
## - V93   1    0.4608  82.447 61.521
## - V10   1    0.5202  82.506 61.645
## - V66   1    0.5910  82.577 61.792
## - V35   1    0.6254  82.611 61.864
## - V56   1    0.6524  82.638 61.920
## - V12   1    0.6822  82.668 61.982
## - V92   1    0.7270  82.713 62.075
## - V62   1    0.8559  82.842 62.343
## - V36   1    0.8997  82.886 62.434
## - V16   1    0.9279  82.914 62.493
## <none>               81.986 62.557
## - V19   1    1.0264  83.012 62.697
## - V81   1    1.0265  83.012 62.697
## - V27   1    1.0775  83.063 62.803
## - V37   1    1.2343  83.220 63.127
## - V24   1    1.2379  83.224 63.135
## - V72   1    1.4404  83.426 63.553
## - V8    1    1.4527  83.439 63.578
## - V17   1    1.4597  83.446 63.592
## - V61   1    1.5707  83.557 63.821
## - V96   1    1.5991  83.585 63.880
## - V59   1    1.6020  83.588 63.885
## - V32   1    1.6196  83.605 63.922
## - V25   1    1.7052  83.691 64.098
## - V13   1    1.8221  83.808 64.338
## - V69   1    1.8515  83.837 64.398
## - V31   1    1.9071  83.893 64.512
## - V68   1    1.9881  83.974 64.678
## - V4    1    2.3273  84.313 65.371
## - V21   1    2.3300  84.316 65.377
## - V83   1    2.3650  84.351 65.448
## - V84   1    2.4303  84.416 65.581
## - V6    1    2.4779  84.464 65.678
## - V44   1    2.6689  84.655 66.067
## - V77   1    2.8562  84.842 66.447
## - V43   1    3.0390  85.025 66.817
## - V14   1    3.1278  85.114 66.997
## - V55   1    3.1415  85.127 67.024
## - V15   1    3.2203  85.206 67.184
## - V7    1    3.2943  85.280 67.333
## - V30   1    3.3103  85.296 67.365
## - V60   1    3.4163  85.402 67.579
## - V5    1    3.9232  85.909 68.597
## - V99   1    4.1070  86.093 68.964
## - V46   1    4.2457  86.232 69.241
## - V26   1    4.3223  86.308 69.394
## - V63   1    4.6700  86.656 70.085
## - V97   1    4.6705  86.656 70.086
## - V82   1    4.7208  86.707 70.186
## - V2    1    5.5716  87.557 71.866
## - V42   1    5.7562  87.742 72.228
## - V23   1    6.4248  88.411 73.534
## - V22   1    6.5343  88.520 73.747
## - V74   1    7.0580  89.044 74.761
## - V45   1    7.0955  89.081 74.833
## - V50   1    7.1804  89.166 74.997
## - V41   1    7.5746  89.560 75.756
## - V85   1    7.8390  89.825 76.263
## - V64   1    8.5798  90.566 77.676
## - V78   1    8.6846  90.670 77.875
## - V73   1    9.0123  90.998 78.495
## - V29   1   10.2780  92.264 80.871
## - V53   1   11.4895  93.475 83.115
## - V28   1   12.8213  94.807 85.548
## - V40   1   13.4115  95.397 86.616
## - V79   1   13.6257  95.612 87.001
## - V1    1   14.8571  96.843 89.202
## - V80   1   15.2247  97.211 89.854
## - V51   1   15.7472  97.733 90.776
## - V52   1   16.0553  98.041 91.318
## - V39   1   20.1624 102.148 98.376
## 
## Step:  AIC=60.59
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V9 + V10 + V11 + 
##     V12 + V13 + V14 + V15 + V16 + V17 + V18 + V19 + V21 + V22 + 
##     V23 + V24 + V25 + V26 + V27 + V28 + V29 + V30 + V31 + V32 + 
##     V33 + V34 + V35 + V36 + V37 + V39 + V40 + V41 + V42 + V43 + 
##     V44 + V45 + V46 + V47 + V48 + V49 + V50 + V51 + V52 + V53 + 
##     V55 + V56 + V57 + V58 + V59 + V60 + V61 + V62 + V63 + V64 + 
##     V65 + V66 + V68 + V69 + V70 + V71 + V72 + V73 + V74 + V76 + 
##     V77 + V78 + V79 + V80 + V81 + V82 + V83 + V84 + V85 + V86 + 
##     V87 + V88 + V90 + V91 + V92 + V93 + V94 + V95 + V96 + V97 + 
##     V98 + V99
## 
##        Df Sum of Sq     RSS    AIC
## - V88   1    0.0247  82.027 58.643
## - V47   1    0.0264  82.029 58.647
## - V76   1    0.0271  82.029 58.648
## - V71   1    0.0291  82.031 58.653
## - V94   1    0.0513  82.054 58.699
## - V90   1    0.0651  82.067 58.728
## - V95   1    0.0750  82.077 58.749
## - V9    1    0.0925  82.095 58.786
## - V91   1    0.0937  82.096 58.788
## - V33   1    0.0979  82.100 58.797
## - V18   1    0.1067  82.109 58.815
## - V70   1    0.1288  82.131 58.862
## - V57   1    0.1953  82.198 59.001
## - V48   1    0.2963  82.299 59.212
## - V49   1    0.2963  82.299 59.212
## - V87   1    0.3144  82.317 59.250
## - V58   1    0.3347  82.337 59.292
## - V98   1    0.3612  82.364 59.348
## - V3    1    0.3774  82.380 59.381
## - V65   1    0.3920  82.394 59.412
## - V86   1    0.4152  82.418 59.460
## - V34   1    0.4331  82.435 59.498
## - V93   1    0.4467  82.449 59.526
## - V11   1    0.4844  82.487 59.605
## - V10   1    0.5763  82.579 59.796
## - V35   1    0.6115  82.614 59.869
## - V66   1    0.6194  82.622 59.886
## - V12   1    0.6868  82.689 60.026
## - V92   1    0.7148  82.717 60.084
## - V56   1    0.7435  82.746 60.144
## - V36   1    0.8832  82.886 60.434
## - V62   1    0.9571  82.959 60.587
## <none>               82.002 60.592
## - V81   1    1.0159  83.018 60.709
## - V16   1    1.0215  83.024 60.721
## - V27   1    1.0756  83.078 60.833
## - V37   1    1.2639  83.266 61.222
## - V72   1    1.4377  83.440 61.581
## - V8    1    1.4534  83.456 61.613
## - V61   1    1.5562  83.559 61.825
## - V59   1    1.5890  83.591 61.893
## - V32   1    1.6319  83.634 61.981
## - V96   1    1.6506  83.653 62.019
## - V17   1    1.6984  83.701 62.118
## - V24   1    1.7109  83.713 62.143
## - V69   1    1.8359  83.838 62.400
## - V25   1    1.8993  83.902 62.530
## - V13   1    1.9280  83.930 62.589
## - V31   1    1.9340  83.936 62.601
## - V68   1    1.9983  84.001 62.733
## - V19   1    2.2187  84.221 63.184
## - V4    1    2.3183  84.321 63.387
## - V84   1    2.4440  84.446 63.643
## - V6    1    2.4653  84.468 63.686
## - V44   1    2.7296  84.732 64.224
## - V77   1    2.8544  84.857 64.477
## - V83   1    2.8698  84.872 64.508
## - V43   1    3.1260  85.128 65.026
## - V55   1    3.1836  85.186 65.143
## - V15   1    3.2193  85.222 65.215
## - V14   1    3.2234  85.226 65.223
## - V7    1    3.3146  85.317 65.407
## - V30   1    3.3340  85.336 65.446
## - V60   1    3.4515  85.454 65.683
## - V5    1    3.9248  85.927 66.633
## - V99   1    4.1005  86.103 66.984
## - V46   1    4.3113  86.314 67.405
## - V26   1    4.3131  86.315 67.408
## - V97   1    4.6595  86.662 68.097
## - V63   1    4.8328  86.835 68.441
## - V82   1    5.2930  87.295 69.350
## - V2    1    5.5557  87.558 69.867
## - V42   1    5.8763  87.879 70.495
## - V45   1    7.0793  89.082 72.834
## - V74   1    7.2057  89.208 73.078
## - V41   1    7.5648  89.567 73.769
## - V85   1    7.8850  89.887 74.383
## - V50   1    8.1661  90.168 74.920
## - V64   1    8.7159  90.718 75.965
## - V78   1    8.7593  90.762 76.048
## - V73   1    8.9965  90.999 76.497
## - V23   1    9.4714  91.474 77.392
## - V29   1   10.2619  92.264 78.872
## - V53   1   11.5156  93.518 81.193
## - V21   1   12.1671  94.169 82.387
## - V28   1   13.0019  95.004 83.905
## - V22   1   13.4689  95.471 84.749
## - V79   1   13.6868  95.689 85.141
## - V40   1   13.8176  95.820 85.376
## - V1    1   15.0412  97.044 87.558
## - V80   1   15.4128  97.415 88.216
## - V52   1   16.2926  98.295 89.762
## - V51   1   16.7762  98.779 90.606
## - V39   1   22.0713 104.074 99.588
## 
## Step:  AIC=58.64
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V9 + V10 + V11 + 
##     V12 + V13 + V14 + V15 + V16 + V17 + V18 + V19 + V21 + V22 + 
##     V23 + V24 + V25 + V26 + V27 + V28 + V29 + V30 + V31 + V32 + 
##     V33 + V34 + V35 + V36 + V37 + V39 + V40 + V41 + V42 + V43 + 
##     V44 + V45 + V46 + V47 + V48 + V49 + V50 + V51 + V52 + V53 + 
##     V55 + V56 + V57 + V58 + V59 + V60 + V61 + V62 + V63 + V64 + 
##     V65 + V66 + V68 + V69 + V70 + V71 + V72 + V73 + V74 + V76 + 
##     V77 + V78 + V79 + V80 + V81 + V82 + V83 + V84 + V85 + V86 + 
##     V87 + V90 + V91 + V92 + V93 + V94 + V95 + V96 + V97 + V98 + 
##     V99
## 
##        Df Sum of Sq     RSS    AIC
## - V47   1    0.0300  82.057 56.706
## - V71   1    0.0365  82.064 56.720
## - V76   1    0.0383  82.065 56.724
## - V94   1    0.0583  82.085 56.766
## - V95   1    0.0625  82.090 56.774
## - V33   1    0.0889  82.116 56.830
## - V9    1    0.0981  82.125 56.849
## - V70   1    0.1148  82.142 56.884
## - V18   1    0.1201  82.147 56.895
## - V91   1    0.1480  82.175 56.953
## - V57   1    0.1804  82.207 57.021
## - V90   1    0.2020  82.229 57.066
## - V48   1    0.2948  82.322 57.260
## - V49   1    0.3227  82.350 57.319
## - V58   1    0.3384  82.365 57.351
## - V98   1    0.3602  82.387 57.397
## - V3    1    0.3608  82.388 57.398
## - V86   1    0.4174  82.444 57.516
## - V65   1    0.4210  82.448 57.524
## - V34   1    0.4331  82.460 57.549
## - V93   1    0.4365  82.464 57.556
## - V11   1    0.4751  82.502 57.637
## - V10   1    0.5822  82.609 57.860
## - V66   1    0.5949  82.622 57.886
## - V35   1    0.6328  82.660 57.965
## - V12   1    0.6781  82.705 58.059
## - V92   1    0.6917  82.719 58.088
## - V56   1    0.7201  82.747 58.147
## <none>               82.027 58.643
## - V36   1    0.9661  82.993 58.657
## - V62   1    0.9865  83.014 58.700
## - V16   1    1.0001  83.027 58.728
## - V81   1    1.0471  83.074 58.825
## - V27   1    1.0755  83.103 58.884
## - V72   1    1.4131  83.440 59.581
## - V37   1    1.4291  83.456 59.614
## - V8    1    1.4311  83.458 59.618
## - V61   1    1.5819  83.609 59.929
## - V32   1    1.6130  83.640 59.993
## - V59   1    1.6242  83.651 60.016
## - V96   1    1.6360  83.663 60.040
## - V17   1    1.6740  83.701 60.118
## - V24   1    1.6862  83.713 60.143
## - V69   1    1.8318  83.859 60.442
## - V87   1    1.8752  83.902 60.531
## - V13   1    1.9050  83.932 60.592
## - V31   1    1.9138  83.941 60.610
## - V68   1    1.9993  84.026 60.785
## - V25   1    2.0555  84.083 60.900
## - V4    1    2.3041  84.331 61.408
## - V19   1    2.3467  84.374 61.495
## - V6    1    2.5144  84.541 61.837
## - V84   1    2.5350  84.562 61.878
## - V77   1    2.8370  84.864 62.492
## - V44   1    2.8391  84.866 62.496
## - V83   1    2.8570  84.884 62.532
## - V55   1    3.1718  85.199 63.169
## - V15   1    3.1961  85.223 63.218
## - V14   1    3.2100  85.237 63.246
## - V30   1    3.3111  85.338 63.450
## - V7    1    3.3954  85.422 63.620
## - V43   1    3.4139  85.441 63.657
## - V60   1    3.4874  85.514 63.805
## - V5    1    4.0113  86.038 64.855
## - V99   1    4.0833  86.110 64.999
## - V46   1    4.3569  86.384 65.545
## - V26   1    4.4850  86.512 65.800
## - V97   1    4.6468  86.674 66.121
## - V63   1    4.8110  86.838 66.447
## - V82   1    5.3790  87.406 67.568
## - V2    1    5.5322  87.559 67.869
## - V42   1    6.7924  88.819 70.327
## - V45   1    7.2206  89.248 71.154
## - V74   1    7.2426  89.270 71.197
## - V85   1    7.8645  89.891 72.391
## - V50   1    8.4463  90.473 73.500
## - V41   1    8.5480  90.575 73.694
## - V78   1    8.7381  90.765 74.054
## - V64   1    8.7611  90.788 74.098
## - V73   1    8.9720  90.999 74.497
## - V23   1    9.4796  91.507 75.454
## - V29   1   10.2630  92.290 76.920
## - V53   1   11.6296  93.657 79.448
## - V21   1   12.3561  94.383 80.777
## - V28   1   12.9814  95.008 81.913
## - V22   1   13.6901  95.717 83.191
## - V79   1   13.8674  95.894 83.510
## - V40   1   14.4471  96.474 84.546
## - V1    1   15.1621  97.189 85.816
## - V80   1   15.4064  97.433 86.248
## - V52   1   16.4790  98.506 88.131
## - V51   1   17.0384  99.065 89.105
## - V39   1   22.7350 104.762 98.722
## 
## Step:  AIC=56.71
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V9 + V10 + V11 + 
##     V12 + V13 + V14 + V15 + V16 + V17 + V18 + V19 + V21 + V22 + 
##     V23 + V24 + V25 + V26 + V27 + V28 + V29 + V30 + V31 + V32 + 
##     V33 + V34 + V35 + V36 + V37 + V39 + V40 + V41 + V42 + V43 + 
##     V44 + V45 + V46 + V48 + V49 + V50 + V51 + V52 + V53 + V55 + 
##     V56 + V57 + V58 + V59 + V60 + V61 + V62 + V63 + V64 + V65 + 
##     V66 + V68 + V69 + V70 + V71 + V72 + V73 + V74 + V76 + V77 + 
##     V78 + V79 + V80 + V81 + V82 + V83 + V84 + V85 + V86 + V87 + 
##     V90 + V91 + V92 + V93 + V94 + V95 + V96 + V97 + V98 + V99
## 
##        Df Sum of Sq     RSS    AIC
## - V71   1    0.0337  82.091 54.777
## - V76   1    0.0392  82.096 54.788
## - V94   1    0.0502  82.107 54.811
## - V95   1    0.0716  82.129 54.856
## - V33   1    0.0852  82.142 54.885
## - V9    1    0.0944  82.151 54.904
## - V70   1    0.1080  82.165 54.932
## - V18   1    0.1202  82.177 54.958
## - V91   1    0.1682  82.225 55.059
## - V57   1    0.1794  82.236 55.082
## - V90   1    0.2337  82.291 55.195
## - V48   1    0.2654  82.322 55.262
## - V49   1    0.3110  82.368 55.357
## - V3    1    0.3390  82.396 55.415
## - V58   1    0.3758  82.433 55.492
## - V98   1    0.3762  82.433 55.493
## - V65   1    0.3925  82.449 55.527
## - V34   1    0.4178  82.475 55.580
## - V86   1    0.4192  82.476 55.583
## - V93   1    0.4349  82.492 55.616
## - V11   1    0.4804  82.537 55.710
## - V66   1    0.6043  82.661 55.968
## - V35   1    0.6298  82.687 56.021
## - V10   1    0.6604  82.717 56.085
## - V12   1    0.6667  82.724 56.098
## - V92   1    0.6732  82.730 56.112
## - V56   1    0.6907  82.748 56.148
## - V36   1    0.9404  82.997 56.666
## <none>               82.057 56.706
## - V16   1    0.9762  83.033 56.740
## - V81   1    1.0347  83.092 56.861
## - V27   1    1.1089  83.166 57.015
## - V62   1    1.1981  83.255 57.199
## - V37   1    1.4033  83.460 57.623
## - V8    1    1.4063  83.463 57.629
## - V72   1    1.4432  83.500 57.705
## - V32   1    1.5905  83.648 58.008
## - V61   1    1.6196  83.677 58.068
## - V59   1    1.6296  83.687 58.089
## - V17   1    1.6474  83.704 58.125
## - V96   1    1.6593  83.716 58.150
## - V69   1    1.8049  83.862 58.448
## - V87   1    1.8490  83.906 58.539
## - V31   1    1.8947  83.952 58.633
## - V13   1    1.9092  83.966 58.662
## - V24   1    1.9600  84.017 58.766
## - V68   1    1.9837  84.041 58.815
## - V25   1    2.0268  84.084 58.903
## - V4    1    2.2742  84.331 59.408
## - V6    1    2.4855  84.543 59.839
## - V84   1    2.5069  84.564 59.882
## - V19   1    2.5120  84.569 59.893
## - V44   1    2.8408  84.898 60.560
## - V83   1    2.8804  84.937 60.640
## - V77   1    2.8950  84.952 60.670
## - V55   1    3.1421  85.199 61.170
## - V14   1    3.2242  85.281 61.335
## - V30   1    3.2856  85.343 61.459
## - V15   1    3.2870  85.344 61.462
## - V7    1    3.3660  85.423 61.621
## - V60   1    3.4638  85.521 61.818
## - V43   1    3.5013  85.558 61.893
## - V5    1    3.9835  86.041 62.860
## - V99   1    4.0563  86.113 63.005
## - V26   1    4.5052  86.562 63.899
## - V97   1    4.6861  86.743 64.259
## - V63   1    5.1789  87.236 65.233
## - V82   1    5.4303  87.487 65.728
## - V2    1    5.5064  87.563 65.877
## - V42   1    6.8303  88.887 68.459
## - V45   1    7.3739  89.431 69.507
## - V74   1    7.4946  89.552 69.739
## - V46   1    7.5983  89.655 69.938
## - V85   1    7.8591  89.916 70.438
## - V50   1    8.4640  90.521 71.591
## - V41   1    8.5200  90.577 71.698
## - V78   1    9.0958  91.153 72.787
## - V64   1    9.1386  91.196 72.868
## - V73   1    9.2069  91.264 72.997
## - V29   1   10.5055  92.563 75.427
## - V23   1   10.5634  92.620 75.535
## - V53   1   11.6221  93.679 77.490
## - V28   1   12.9521  95.009 79.914
## - V21   1   13.1506  95.208 80.273
## - V79   1   14.0203  96.077 81.837
## - V40   1   14.4257  96.483 82.562
## - V22   1   14.7259  96.783 83.096
## - V80   1   15.3773  97.434 84.250
## - V1    1   15.4147  97.472 84.316
## - V52   1   16.4576  98.515 86.146
## - V51   1   17.0339  99.091 87.150
## - V39   1   22.7319 104.789 96.766
## 
## Step:  AIC=54.78
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V9 + V10 + V11 + 
##     V12 + V13 + V14 + V15 + V16 + V17 + V18 + V19 + V21 + V22 + 
##     V23 + V24 + V25 + V26 + V27 + V28 + V29 + V30 + V31 + V32 + 
##     V33 + V34 + V35 + V36 + V37 + V39 + V40 + V41 + V42 + V43 + 
##     V44 + V45 + V46 + V48 + V49 + V50 + V51 + V52 + V53 + V55 + 
##     V56 + V57 + V58 + V59 + V60 + V61 + V62 + V63 + V64 + V65 + 
##     V66 + V68 + V69 + V70 + V72 + V73 + V74 + V76 + V77 + V78 + 
##     V79 + V80 + V81 + V82 + V83 + V84 + V85 + V86 + V87 + V90 + 
##     V91 + V92 + V93 + V94 + V95 + V96 + V97 + V98 + V99
## 
##        Df Sum of Sq     RSS    AIC
## - V76   1    0.0267  82.117 52.833
## - V95   1    0.0683  82.159 52.920
## - V94   1    0.0796  82.170 52.944
## - V33   1    0.0881  82.179 52.961
## - V9    1    0.1085  82.199 53.004
## - V91   1    0.1369  82.228 53.064
## - V18   1    0.1425  82.233 53.075
## - V57   1    0.1848  82.276 53.164
## - V90   1    0.2010  82.292 53.198
## - V49   1    0.2837  82.374 53.370
## - V48   1    0.3135  82.404 53.433
## - V3    1    0.3386  82.429 53.485
## - V65   1    0.3768  82.468 53.565
## - V86   1    0.3915  82.482 53.595
## - V93   1    0.4115  82.502 53.637
## - V58   1    0.4331  82.524 53.682
## - V34   1    0.4350  82.526 53.686
## - V98   1    0.4933  82.584 53.807
## - V11   1    0.5183  82.609 53.859
## - V35   1    0.5992  82.690 54.028
## - V66   1    0.6285  82.719 54.089
## - V12   1    0.6340  82.725 54.100
## - V10   1    0.6435  82.734 54.120
## - V56   1    0.6841  82.775 54.204
## - V92   1    0.7856  82.876 54.415
## - V70   1    0.7981  82.889 54.441
## - V36   1    0.9078  82.999 54.668
## - V16   1    0.9425  83.033 54.740
## <none>               82.091 54.777
## - V27   1    1.0924  83.183 55.051
## - V81   1    1.2134  83.304 55.301
## - V37   1    1.3700  83.461 55.624
## - V62   1    1.4535  83.544 55.796
## - V8    1    1.5088  83.600 55.909
## - V32   1    1.6310  83.722 56.161
## - V17   1    1.6909  83.782 56.284
## - V59   1    1.7283  83.819 56.360
## - V61   1    1.8560  83.947 56.622
## - V13   1    1.8761  83.967 56.664
## - V31   1    1.9529  84.044 56.821
## - V24   1    1.9712  84.062 56.858
## - V68   1    2.0454  84.136 57.010
## - V87   1    2.0729  84.164 57.066
## - V96   1    2.1148  84.206 57.152
## - V25   1    2.1693  84.260 57.263
## - V4    1    2.3015  84.392 57.533
## - V69   1    2.4946  84.585 57.926
## - V84   1    2.5196  84.610 57.977
## - V19   1    2.5318  84.623 58.002
## - V6    1    2.6645  84.755 58.271
## - V44   1    2.8712  84.962 58.690
## - V83   1    2.9073  84.998 58.763
## - V72   1    3.0417  85.132 59.035
## - V55   1    3.1518  85.243 59.257
## - V14   1    3.2001  85.291 59.354
## - V15   1    3.3535  85.444 59.664
## - V30   1    3.3709  85.462 59.699
## - V7    1    3.4703  85.561 59.898
## - V60   1    3.5376  85.628 60.034
## - V77   1    3.5493  85.640 60.057
## - V43   1    3.8687  85.959 60.698
## - V99   1    4.0229  86.114 61.006
## - V5    1    4.1212  86.212 61.202
## - V26   1    5.0151  87.106 62.976
## - V63   1    5.1917  87.282 63.325
## - V82   1    5.4058  87.497 63.746
## - V2    1    5.6003  87.691 64.128
## - V97   1    6.3668  88.458 65.625
## - V42   1    7.3000  89.391 67.430
## - V45   1    7.6270  89.718 68.058
## - V74   1    7.6876  89.778 68.174
## - V85   1    7.8294  89.920 68.446
## - V46   1    7.8792  89.970 68.541
## - V50   1    8.4513  90.542 69.631
## - V41   1    8.8468  90.938 70.381
## - V64   1    9.1214  91.212 70.899
## - V78   1    9.2690  91.360 71.177
## - V73   1    9.9183  92.009 72.396
## - V29   1   10.5118  92.603 73.501
## - V23   1   10.7401  92.831 73.925
## - V53   1   11.6681  93.759 75.636
## - V21   1   13.1207  95.211 78.280
## - V28   1   13.2410  95.332 78.497
## - V79   1   14.0275  96.118 79.911
## - V22   1   14.7237  96.814 81.152
## - V40   1   14.8165  96.907 81.317
## - V1    1   15.4892  97.580 82.506
## - V52   1   16.5782  98.669 84.416
## - V80   1   16.8780  98.969 84.937
## - V51   1   17.2514  99.342 85.585
## - V39   1   22.8604 104.951 95.032
## 
## Step:  AIC=52.83
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V9 + V10 + V11 + 
##     V12 + V13 + V14 + V15 + V16 + V17 + V18 + V19 + V21 + V22 + 
##     V23 + V24 + V25 + V26 + V27 + V28 + V29 + V30 + V31 + V32 + 
##     V33 + V34 + V35 + V36 + V37 + V39 + V40 + V41 + V42 + V43 + 
##     V44 + V45 + V46 + V48 + V49 + V50 + V51 + V52 + V53 + V55 + 
##     V56 + V57 + V58 + V59 + V60 + V61 + V62 + V63 + V64 + V65 + 
##     V66 + V68 + V69 + V70 + V72 + V73 + V74 + V77 + V78 + V79 + 
##     V80 + V81 + V82 + V83 + V84 + V85 + V86 + V87 + V90 + V91 + 
##     V92 + V93 + V94 + V95 + V96 + V97 + V98 + V99
## 
##        Df Sum of Sq     RSS    AIC
## - V95   1    0.0721  82.189 50.984
## - V94   1    0.0805  82.198 51.001
## - V33   1    0.0990  82.216 51.040
## - V91   1    0.1247  82.242 51.094
## - V18   1    0.1308  82.248 51.106
## - V9    1    0.1375  82.255 51.120
## - V90   1    0.1800  82.297 51.209
## - V57   1    0.1868  82.304 51.224
## - V49   1    0.2683  82.386 51.394
## - V48   1    0.3139  82.431 51.489
## - V3    1    0.3318  82.449 51.526
## - V86   1    0.3798  82.497 51.626
## - V65   1    0.4121  82.529 51.694
## - V34   1    0.4129  82.530 51.695
## - V93   1    0.4160  82.533 51.702
## - V58   1    0.4186  82.536 51.707
## - V98   1    0.4867  82.604 51.849
## - V11   1    0.4946  82.612 51.866
## - V35   1    0.5979  82.715 52.081
## - V66   1    0.6033  82.721 52.092
## - V12   1    0.6497  82.767 52.188
## - V56   1    0.7374  82.855 52.370
## - V10   1    0.7684  82.886 52.435
## - V70   1    0.7723  82.890 52.443
## - V92   1    0.7981  82.915 52.496
## - V36   1    0.8823  83.000 52.671
## - V16   1    0.9261  83.043 52.762
## <none>               82.117 52.833
## - V27   1    1.0783  83.196 53.077
## - V37   1    1.3577  83.475 53.653
## - V81   1    1.4484  83.566 53.840
## - V8    1    1.5276  83.645 54.003
## - V62   1    1.6051  83.723 54.162
## - V32   1    1.6235  83.741 54.200
## - V59   1    1.7220  83.839 54.402
## - V17   1    1.7419  83.859 54.443
## - V13   1    1.8929  84.010 54.753
## - V31   1    1.9303  84.048 54.829
## - V61   1    1.9325  84.050 54.834
## - V24   1    1.9550  84.072 54.880
## - V68   1    2.0450  84.162 55.064
## - V87   1    2.1195  84.237 55.216
## - V96   1    2.1801  84.298 55.340
## - V4    1    2.2749  84.392 55.533
## - V25   1    2.2967  84.414 55.577
## - V69   1    2.5434  84.661 56.079
## - V84   1    2.5493  84.667 56.091
## - V19   1    2.5606  84.678 56.114
## - V6    1    2.6676  84.785 56.331
## - V44   1    2.9068  85.024 56.816
## - V83   1    2.9595  85.077 56.923
## - V72   1    3.0333  85.151 57.072
## - V14   1    3.2459  85.363 57.501
## - V55   1    3.3358  85.453 57.682
## - V30   1    3.3795  85.497 57.770
## - V15   1    3.4630  85.580 57.938
## - V7    1    3.5318  85.649 58.076
## - V60   1    3.5359  85.653 58.084
## - V43   1    3.8513  85.969 58.716
## - V99   1    4.0933  86.211 59.200
## - V5    1    4.0947  86.212 59.202
## - V26   1    5.0423  87.160 61.083
## - V63   1    5.3705  87.488 61.729
## - V2    1    5.5740  87.691 62.129
## - V82   1    5.7843  87.902 62.541
## - V97   1    6.4045  88.522 63.750
## - V42   1    7.2841  89.402 65.451
## - V85   1    7.8040  89.921 66.448
## - V77   1    7.8938  90.011 66.620
## - V45   1    8.3479  90.465 67.485
## - V50   1    8.4544  90.572 67.688
## - V46   1    8.6418  90.759 68.043
## - V41   1    8.8207  90.938 68.382
## - V74   1    8.8712  90.989 68.477
## - V64   1    9.1171  91.235 68.942
## - V73   1   10.1198  92.237 70.822
## - V78   1   10.6283  92.746 71.767
## - V29   1   10.7515  92.869 71.995
## - V23   1   10.8231  92.940 72.128
## - V53   1   11.7495  93.867 73.834
## - V28   1   13.2593  95.377 76.579
## - V21   1   13.2594  95.377 76.579
## - V79   1   14.1076  96.225 78.102
## - V22   1   14.8109  96.928 79.354
## - V40   1   14.9002  97.018 79.512
## - V1    1   15.4772  97.595 80.532
## - V52   1   16.5588  98.676 82.428
## - V80   1   17.0463  99.164 83.276
## - V51   1   17.2438  99.361 83.618
## - V39   1   23.2089 105.326 93.646
## 
## Step:  AIC=50.98
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V9 + V10 + V11 + 
##     V12 + V13 + V14 + V15 + V16 + V17 + V18 + V19 + V21 + V22 + 
##     V23 + V24 + V25 + V26 + V27 + V28 + V29 + V30 + V31 + V32 + 
##     V33 + V34 + V35 + V36 + V37 + V39 + V40 + V41 + V42 + V43 + 
##     V44 + V45 + V46 + V48 + V49 + V50 + V51 + V52 + V53 + V55 + 
##     V56 + V57 + V58 + V59 + V60 + V61 + V62 + V63 + V64 + V65 + 
##     V66 + V68 + V69 + V70 + V72 + V73 + V74 + V77 + V78 + V79 + 
##     V80 + V81 + V82 + V83 + V84 + V85 + V86 + V87 + V90 + V91 + 
##     V92 + V93 + V94 + V96 + V97 + V98 + V99
## 
##        Df Sum of Sq     RSS    AIC
## - V91   1    0.0993  82.289 49.191
## - V18   1    0.1056  82.295 49.204
## - V9    1    0.1248  82.314 49.245
## - V33   1    0.1253  82.315 49.246
## - V90   1    0.1609  82.350 49.320
## - V57   1    0.2266  82.416 49.457
## - V48   1    0.2821  82.472 49.573
## - V49   1    0.3224  82.512 49.657
## - V3    1    0.3557  82.545 49.726
## - V65   1    0.3684  82.558 49.753
## - V94   1    0.3839  82.573 49.785
## - V93   1    0.3938  82.583 49.806
## - V86   1    0.3939  82.583 49.806
## - V34   1    0.4038  82.593 49.827
## - V98   1    0.4519  82.641 49.927
## - V11   1    0.4564  82.646 49.936
## - V58   1    0.4574  82.647 49.938
## - V35   1    0.5752  82.765 50.183
## - V66   1    0.6362  82.826 50.310
## - V12   1    0.6790  82.868 50.399
## - V56   1    0.7646  82.954 50.576
## - V10   1    0.7657  82.955 50.579
## - V70   1    0.7805  82.970 50.609
## - V92   1    0.9169  83.106 50.892
## - V36   1    0.9221  83.112 50.903
## <none>               82.189 50.984
## - V27   1    1.0413  83.231 51.149
## - V16   1    1.0468  83.236 51.160
## - V37   1    1.4350  83.625 51.961
## - V81   1    1.5291  83.719 52.154
## - V8    1    1.5716  83.761 52.242
## - V62   1    1.5845  83.774 52.268
## - V32   1    1.7003  83.890 52.506
## - V17   1    1.7755  83.965 52.660
## - V59   1    1.7898  83.979 52.689
## - V24   1    1.8952  84.085 52.905
## - V61   1    1.9095  84.099 52.934
## - V31   1    1.9305  84.120 52.977
## - V13   1    1.9420  84.131 53.000
## - V68   1    2.0121  84.202 53.144
## - V87   1    2.1081  84.298 53.340
## - V4    1    2.2871  84.477 53.705
## - V25   1    2.3071  84.497 53.745
## - V84   1    2.5011  84.691 54.140
## - V69   1    2.5111  84.701 54.160
## - V19   1    2.5257  84.715 54.190
## - V6    1    2.6188  84.808 54.379
## - V44   1    2.8490  85.039 54.845
## - V96   1    2.8591  85.049 54.865
## - V83   1    2.9687  85.158 55.087
## - V72   1    3.0137  85.203 55.177
## - V55   1    3.2794  85.469 55.713
## - V14   1    3.2807  85.470 55.716
## - V30   1    3.3408  85.530 55.837
## - V15   1    3.4143  85.604 55.984
## - V7    1    3.4696  85.659 56.095
## - V60   1    3.5986  85.788 56.354
## - V43   1    3.8275  86.017 56.813
## - V5    1    4.0690  86.258 57.295
## - V99   1    4.2861  86.476 57.727
## - V26   1    4.9761  87.166 59.094
## - V63   1    5.3189  87.508 59.769
## - V2    1    5.6512  87.841 60.421
## - V82   1    5.7136  87.903 60.543
## - V97   1    6.3638  88.553 61.811
## - V42   1    7.2298  89.419 63.485
## - V85   1    7.8147  90.004 64.606
## - V77   1    7.8229  90.012 64.622
## - V45   1    8.3074  90.497 65.545
## - V50   1    8.5838  90.773 66.070
## - V41   1    8.8056  90.995 66.489
## - V46   1    8.8760  91.065 66.623
## - V74   1    8.9458  91.135 66.754
## - V64   1    9.0681  91.258 66.985
## - V73   1   10.1993  92.389 69.104
## - V29   1   10.6975  92.887 70.029
## - V78   1   10.7346  92.924 70.098
## - V23   1   10.7537  92.943 70.133
## - V53   1   11.7914  93.981 72.043
## - V28   1   13.1889  95.378 74.581
## - V21   1   13.4463  95.636 75.045
## - V79   1   14.1024  96.292 76.221
## - V22   1   14.8377  97.027 77.529
## - V40   1   15.1217  97.311 78.032
## - V1    1   15.9557  98.145 79.500
## - V52   1   16.6476  98.837 80.708
## - V51   1   17.1743  99.364 81.622
## - V80   1   17.1824  99.372 81.636
## - V39   1   23.4575 105.647 92.169
## 
## Step:  AIC=49.19
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V9 + V10 + V11 + 
##     V12 + V13 + V14 + V15 + V16 + V17 + V18 + V19 + V21 + V22 + 
##     V23 + V24 + V25 + V26 + V27 + V28 + V29 + V30 + V31 + V32 + 
##     V33 + V34 + V35 + V36 + V37 + V39 + V40 + V41 + V42 + V43 + 
##     V44 + V45 + V46 + V48 + V49 + V50 + V51 + V52 + V53 + V55 + 
##     V56 + V57 + V58 + V59 + V60 + V61 + V62 + V63 + V64 + V65 + 
##     V66 + V68 + V69 + V70 + V72 + V73 + V74 + V77 + V78 + V79 + 
##     V80 + V81 + V82 + V83 + V84 + V85 + V86 + V87 + V90 + V92 + 
##     V93 + V94 + V96 + V97 + V98 + V99
## 
##        Df Sum of Sq     RSS    AIC
## - V90   1    0.0770  82.366 47.352
## - V33   1    0.1115  82.400 47.424
## - V18   1    0.1169  82.406 47.436
## - V57   1    0.1726  82.461 47.552
## - V9    1    0.1806  82.469 47.568
## - V49   1    0.2392  82.528 47.691
## - V86   1    0.3078  82.597 47.833
## - V3    1    0.3747  82.663 47.973
## - V94   1    0.3798  82.669 47.983
## - V58   1    0.3803  82.669 47.984
## - V48   1    0.4210  82.710 48.069
## - V11   1    0.4247  82.713 48.077
## - V65   1    0.4375  82.726 48.103
## - V34   1    0.4839  82.773 48.200
## - V35   1    0.4960  82.785 48.225
## - V98   1    0.5268  82.816 48.289
## - V93   1    0.6635  82.952 48.573
## - V66   1    0.6747  82.963 48.596
## - V56   1    0.7216  83.010 48.693
## - V12   1    0.7229  83.012 48.696
## - V10   1    0.7909  83.080 48.837
## - V36   1    0.8354  83.124 48.929
## - V70   1    0.8481  83.137 48.955
## - V27   1    0.9575  83.246 49.181
## <none>               82.289 49.191
## - V16   1    1.0517  83.340 49.376
## - V37   1    1.3923  83.681 50.077
## - V62   1    1.5083  83.797 50.315
## - V32   1    1.6777  83.966 50.663
## - V59   1    1.6937  83.982 50.696
## - V81   1    1.7248  84.014 50.759
## - V17   1    1.7785  84.067 50.869
## - V24   1    1.7975  84.086 50.908
## - V8    1    1.8201  84.109 50.954
## - V31   1    1.9000  84.189 51.118
## - V13   1    1.9547  84.243 51.229
## - V61   1    1.9763  84.265 51.273
## - V68   1    2.3519  84.641 52.038
## - V25   1    2.3984  84.687 52.133
## - V19   1    2.4981  84.787 52.335
## - V4    1    2.5263  84.815 52.392
## - V84   1    2.6781  84.967 52.700
## - V44   1    2.7507  85.039 52.847
## - V83   1    2.8901  85.179 53.128
## - V69   1    3.0430  85.332 53.437
## - V72   1    3.1063  85.395 53.565
## - V6    1    3.1091  85.398 53.570
## - V14   1    3.2326  85.521 53.819
## - V55   1    3.2979  85.587 53.950
## - V30   1    3.3164  85.605 53.987
## - V15   1    3.3418  85.631 54.038
## - V87   1    3.3484  85.637 54.051
## - V96   1    3.3874  85.676 54.130
## - V60   1    3.5862  85.875 54.528
## - V43   1    3.7340  86.023 54.824
## - V7    1    3.9761  86.265 55.308
## - V99   1    4.2666  86.555 55.886
## - V5    1    4.5873  86.876 56.522
## - V26   1    4.8839  87.173 57.108
## - V82   1    5.6893  87.978 58.690
## - V2    1    5.9218  88.211 59.144
## - V92   1    6.0351  88.324 59.365
## - V63   1    6.0616  88.350 59.416
## - V42   1    7.1427  89.431 61.508
## - V97   1    7.3595  89.648 61.925
## - V85   1    7.7158  90.005 62.607
## - V77   1    7.8871  90.176 62.934
## - V45   1    8.2154  90.504 63.559
## - V41   1    8.7098  90.999 64.496
## - V46   1    8.8107  91.099 64.687
## - V50   1    8.8457  91.134 64.753
## - V74   1    9.6975  91.986 66.353
## - V73   1   10.5112  92.800 67.868
## - V64   1   10.5417  92.830 67.924
## - V29   1   10.5983  92.887 68.029
## - V78   1   10.6605  92.949 68.144
## - V23   1   11.1394  93.428 69.028
## - V53   1   11.7025  93.991 70.062
## - V21   1   13.5038  95.793 73.327
## - V28   1   13.8449  96.134 73.938
## - V79   1   14.0481  96.337 74.301
## - V40   1   15.0409  97.330 76.065
## - V22   1   15.1855  97.474 76.320
## - V1    1   16.3292  98.618 78.327
## - V52   1   16.6828  98.972 78.942
## - V80   1   17.4817  99.770 80.325
## - V51   1   17.5772  99.866 80.490
## - V39   1   23.3806 105.669 90.205
## 
## Step:  AIC=47.35
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V9 + V10 + V11 + 
##     V12 + V13 + V14 + V15 + V16 + V17 + V18 + V19 + V21 + V22 + 
##     V23 + V24 + V25 + V26 + V27 + V28 + V29 + V30 + V31 + V32 + 
##     V33 + V34 + V35 + V36 + V37 + V39 + V40 + V41 + V42 + V43 + 
##     V44 + V45 + V46 + V48 + V49 + V50 + V51 + V52 + V53 + V55 + 
##     V56 + V57 + V58 + V59 + V60 + V61 + V62 + V63 + V64 + V65 + 
##     V66 + V68 + V69 + V70 + V72 + V73 + V74 + V77 + V78 + V79 + 
##     V80 + V81 + V82 + V83 + V84 + V85 + V86 + V87 + V92 + V93 + 
##     V94 + V96 + V97 + V98 + V99
## 
##        Df Sum of Sq     RSS    AIC
## - V18   1    0.0965  82.462 45.554
## - V33   1    0.1368  82.502 45.637
## - V57   1    0.1815  82.547 45.731
## - V9    1    0.1910  82.557 45.750
## - V49   1    0.2154  82.581 45.801
## - V86   1    0.2349  82.601 45.842
## - V48   1    0.3935  82.759 46.172
## - V65   1    0.3982  82.764 46.182
## - V3    1    0.4019  82.768 46.189
## - V94   1    0.4491  82.815 46.287
## - V34   1    0.4593  82.825 46.309
## - V35   1    0.4676  82.833 46.326
## - V58   1    0.4848  82.851 46.361
## - V11   1    0.5083  82.874 46.410
## - V98   1    0.5615  82.927 46.521
## - V93   1    0.5885  82.954 46.577
## - V12   1    0.6617  83.027 46.728
## - V56   1    0.7150  83.081 46.839
## - V66   1    0.7398  83.106 46.890
## - V10   1    0.7722  83.138 46.957
## - V36   1    0.8030  83.169 47.021
## - V70   1    0.8934  83.259 47.208
## - V27   1    0.9464  83.312 47.317
## <none>               82.366 47.352
## - V16   1    1.0089  83.375 47.446
## - V37   1    1.3612  83.727 48.171
## - V62   1    1.4501  83.816 48.354
## - V81   1    1.6485  84.014 48.761
## - V32   1    1.6997  84.065 48.865
## - V17   1    1.7208  84.086 48.908
## - V24   1    1.7410  84.107 48.950
## - V8    1    1.8292  84.195 49.130
## - V59   1    1.8436  84.209 49.160
## - V31   1    1.8686  84.234 49.211
## - V13   1    1.8889  84.255 49.252
## - V61   1    1.9850  84.351 49.448
## - V68   1    2.3230  84.689 50.136
## - V19   1    2.4313  84.797 50.356
## - V25   1    2.4448  84.811 50.383
## - V84   1    2.6087  84.974 50.715
## - V4    1    2.7152  85.081 50.931
## - V83   1    2.8396  85.205 51.182
## - V44   1    2.9681  85.334 51.441
## - V69   1    3.1260  85.492 51.759
## - V14   1    3.1995  85.565 51.907
## - V30   1    3.2664  85.632 52.041
## - V96   1    3.3404  85.706 52.190
## - V6    1    3.3478  85.714 52.205
## - V55   1    3.3498  85.715 52.209
## - V15   1    3.3934  85.759 52.296
## - V72   1    3.5365  85.902 52.583
## - V60   1    3.6297  85.995 52.770
## - V99   1    4.1902  86.556 53.887
## - V7    1    4.2734  86.639 54.052
## - V43   1    4.3016  86.667 54.108
## - V26   1    4.8175  87.183 55.129
## - V5    1    4.8476  87.213 55.188
## - V87   1    5.6350  88.001 56.734
## - V82   1    5.6518  88.018 56.767
## - V2    1    5.9066  88.272 57.264
## - V63   1    6.0438  88.410 57.532
## - V97   1    7.3050  89.671 59.968
## - V77   1    7.8105  90.176 60.935
## - V42   1    7.8122  90.178 60.938
## - V85   1    7.8873  90.253 61.081
## - V45   1    8.1384  90.504 61.559
## - V46   1    8.8892  91.255 62.980
## - V50   1    8.9494  91.315 63.093
## - V41   1    9.0691  91.435 63.319
## - V74   1    9.8542  92.220 64.789
## - V92   1   10.3494  92.715 65.710
## - V64   1   10.4648  92.830 65.924
## - V29   1   10.5214  92.887 66.029
## - V78   1   10.8880  93.254 66.707
## - V23   1   11.0726  93.438 67.047
## - V53   1   11.7413  94.107 68.273
## - V73   1   11.7418  94.108 68.274
## - V21   1   13.5030  95.869 71.464
## - V28   1   13.8473  96.213 72.080
## - V79   1   14.0452  96.411 72.433
## - V40   1   15.0873  97.453 74.283
## - V22   1   15.1887  97.554 74.462
## - V1    1   16.2671  98.633 76.352
## - V52   1   16.6090  98.975 76.948
## - V51   1   17.6790 100.045 78.797
## - V80   1   17.7371 100.103 78.897
## - V39   1   23.3148 105.681 88.223
## 
## Step:  AIC=45.55
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V9 + V10 + V11 + 
##     V12 + V13 + V14 + V15 + V16 + V17 + V19 + V21 + V22 + V23 + 
##     V24 + V25 + V26 + V27 + V28 + V29 + V30 + V31 + V32 + V33 + 
##     V34 + V35 + V36 + V37 + V39 + V40 + V41 + V42 + V43 + V44 + 
##     V45 + V46 + V48 + V49 + V50 + V51 + V52 + V53 + V55 + V56 + 
##     V57 + V58 + V59 + V60 + V61 + V62 + V63 + V64 + V65 + V66 + 
##     V68 + V69 + V70 + V72 + V73 + V74 + V77 + V78 + V79 + V80 + 
##     V81 + V82 + V83 + V84 + V85 + V86 + V87 + V92 + V93 + V94 + 
##     V96 + V97 + V98 + V99
## 
##        Df Sum of Sq     RSS    AIC
## - V9    1    0.1492  82.611 43.864
## - V33   1    0.1646  82.627 43.896
## - V57   1    0.1692  82.631 43.906
## - V86   1    0.2104  82.673 43.992
## - V49   1    0.2746  82.737 44.125
## - V48   1    0.3172  82.780 44.214
## - V65   1    0.3480  82.810 44.278
## - V34   1    0.3872  82.849 44.359
## - V94   1    0.4122  82.874 44.411
## - V3    1    0.4276  82.890 44.443
## - V11   1    0.4424  82.905 44.474
## - V58   1    0.4628  82.925 44.516
## - V98   1    0.5207  82.983 44.636
## - V35   1    0.6102  83.072 44.822
## - V93   1    0.6542  83.116 44.913
## - V56   1    0.7002  83.162 45.008
## - V12   1    0.7949  83.257 45.204
## - V10   1    0.8358  83.298 45.288
## - V66   1    0.8363  83.299 45.289
## - V36   1    0.8387  83.301 45.294
## - V70   1    0.8839  83.346 45.387
## <none>               82.462 45.554
## - V27   1    1.1027  83.565 45.838
## - V16   1    1.3034  83.766 46.251
## - V37   1    1.3355  83.798 46.317
## - V62   1    1.4269  83.889 46.504
## - V81   1    1.6871  84.149 47.037
## - V24   1    1.7419  84.204 47.149
## - V17   1    1.7835  84.246 47.234
## - V32   1    1.7945  84.257 47.256
## - V8    1    1.8943  84.357 47.460
## - V59   1    1.9117  84.374 47.496
## - V61   1    1.9547  84.417 47.583
## - V31   1    2.0074  84.470 47.691
## - V13   1    2.1081  84.570 47.895
## - V25   1    2.3753  84.838 48.438
## - V84   1    2.5129  84.975 48.717
## - V68   1    2.5211  84.983 48.733
## - V83   1    2.8778  85.340 49.454
## - V44   1    2.9226  85.385 49.544
## - V19   1    3.0114  85.474 49.723
## - V4    1    3.0172  85.479 49.734
## - V69   1    3.2380  85.700 50.178
## - V96   1    3.2540  85.716 50.210
## - V14   1    3.2819  85.744 50.266
## - V15   1    3.2981  85.760 50.299
## - V55   1    3.3763  85.839 50.455
## - V30   1    3.3818  85.844 50.467
## - V6    1    3.6517  86.114 51.007
## - V60   1    3.8339  86.296 51.370
## - V72   1    3.9601  86.422 51.621
## - V43   1    4.2865  86.749 52.270
## - V99   1    4.4179  86.880 52.530
## - V26   1    4.7691  87.231 53.224
## - V7    1    4.7730  87.235 53.232
## - V5    1    5.3852  87.847 54.435
## - V82   1    5.5638  88.026 54.784
## - V87   1    5.7084  88.171 55.066
## - V63   1    5.9485  88.411 55.534
## - V2    1    5.9755  88.438 55.586
## - V97   1    7.2259  89.688 58.001
## - V77   1    7.7844  90.247 59.069
## - V85   1    7.8012  90.263 59.101
## - V42   1    8.0688  90.531 59.610
## - V45   1    8.1021  90.564 59.673
## - V46   1    8.7928  91.255 60.980
## - V50   1    8.8609  91.323 61.109
## - V41   1    9.4788  91.941 62.268
## - V74   1    9.8496  92.312 62.961
## - V64   1   10.4982  92.960 64.165
## - V29   1   10.5290  92.991 64.222
## - V92   1   10.6852  93.147 64.511
## - V78   1   10.8281  93.290 64.774
## - V23   1   11.0437  93.506 65.171
## - V53   1   11.8918  94.354 66.724
## - V73   1   12.2871  94.749 67.443
## - V21   1   13.5372  96.000 69.698
## - V28   1   13.9129  96.375 70.370
## - V79   1   13.9775  96.440 70.485
## - V22   1   15.2076  97.670 72.665
## - V40   1   15.2852  97.747 72.801
## - V1    1   16.5291  98.991 74.977
## - V52   1   16.5672  99.029 75.043
## - V51   1   17.6285 100.091 76.876
## - V80   1   17.6408 100.103 76.897
## - V39   1   23.3338 105.796 86.411
## 
## Step:  AIC=43.86
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V10 + V11 + V12 + 
##     V13 + V14 + V15 + V16 + V17 + V19 + V21 + V22 + V23 + V24 + 
##     V25 + V26 + V27 + V28 + V29 + V30 + V31 + V32 + V33 + V34 + 
##     V35 + V36 + V37 + V39 + V40 + V41 + V42 + V43 + V44 + V45 + 
##     V46 + V48 + V49 + V50 + V51 + V52 + V53 + V55 + V56 + V57 + 
##     V58 + V59 + V60 + V61 + V62 + V63 + V64 + V65 + V66 + V68 + 
##     V69 + V70 + V72 + V73 + V74 + V77 + V78 + V79 + V80 + V81 + 
##     V82 + V83 + V84 + V85 + V86 + V87 + V92 + V93 + V94 + V96 + 
##     V97 + V98 + V99
## 
##        Df Sum of Sq     RSS    AIC
## - V57   1    0.1428  82.754 42.162
## - V86   1    0.1502  82.762 42.177
## - V33   1    0.1605  82.772 42.198
## - V49   1    0.2398  82.851 42.363
## - V65   1    0.3443  82.956 42.580
## - V48   1    0.3599  82.971 42.612
## - V58   1    0.3645  82.976 42.622
## - V34   1    0.3715  82.983 42.636
## - V94   1    0.3991  83.011 42.693
## - V11   1    0.4962  83.108 42.895
## - V3    1    0.5681  83.180 43.043
## - V98   1    0.5689  83.180 43.045
## - V35   1    0.6609  83.272 43.235
## - V93   1    0.6704  83.282 43.255
## - V56   1    0.6788  83.290 43.272
## - V10   1    0.6876  83.299 43.290
## - V12   1    0.7565  83.368 43.432
## - V66   1    0.9038  83.515 43.736
## <none>               82.611 43.864
## - V36   1    1.0099  83.621 43.954
## - V70   1    1.0118  83.623 43.958
## - V27   1    1.2206  83.832 44.387
## - V62   1    1.3896  84.001 44.734
## - V16   1    1.4015  84.013 44.758
## - V37   1    1.5848  84.196 45.133
## - V24   1    1.6067  84.218 45.178
## - V81   1    1.7282  84.340 45.425
## - V59   1    1.7627  84.374 45.496
## - V17   1    1.7761  84.388 45.523
## - V32   1    1.7819  84.393 45.535
## - V8    1    1.8174  84.429 45.607
## - V61   1    1.8825  84.494 45.740
## - V13   1    2.0253  84.637 46.030
## - V31   1    2.0808  84.692 46.143
## - V84   1    2.5891  85.201 47.172
## - V25   1    2.5997  85.211 47.194
## - V83   1    2.7529  85.364 47.503
## - V68   1    2.9827  85.594 47.965
## - V4    1    3.0329  85.644 48.066
## - V44   1    3.0584  85.670 48.117
## - V19   1    3.0945  85.706 48.190
## - V14   1    3.1858  85.797 48.373
## - V15   1    3.2315  85.843 48.464
## - V96   1    3.2773  85.889 48.556
## - V55   1    3.3068  85.918 48.615
## - V6    1    3.5341  86.146 49.069
## - V30   1    3.6580  86.269 49.317
## - V60   1    3.6864  86.298 49.373
## - V69   1    3.7248  86.336 49.450
## - V72   1    3.9973  86.609 49.992
## - V43   1    4.3040  86.915 50.600
## - V99   1    4.4127  87.024 50.815
## - V7    1    4.6243  87.236 51.233
## - V26   1    4.6962  87.308 51.374
## - V5    1    5.2854  87.897 52.531
## - V82   1    5.4726  88.084 52.897
## - V2    1    5.8908  88.502 53.712
## - V63   1    6.0012  88.613 53.926
## - V87   1    6.6244  89.236 55.132
## - V97   1    7.4411  90.053 56.699
## - V85   1    7.6775  90.289 57.149
## - V77   1    7.7362  90.348 57.261
## - V42   1    7.9343  90.546 57.638
## - V45   1    8.3849  90.996 58.492
## - V50   1    8.7196  91.331 59.123
## - V46   1    9.2656  91.877 60.149
## - V41   1    9.3308  91.942 60.271
## - V74   1   10.1560  92.767 61.807
## - V64   1   10.5283  93.140 62.496
## - V78   1   10.6818  93.293 62.780
## - V92   1   10.7280  93.339 62.865
## - V23   1   10.9024  93.514 63.186
## - V29   1   11.6351  94.247 64.528
## - V53   1   11.8159  94.427 64.858
## - V73   1   12.6744  95.286 66.415
## - V21   1   13.4328  96.044 67.778
## - V79   1   13.8523  96.464 68.528
## - V22   1   15.0649  97.676 70.676
## - V40   1   15.1573  97.769 70.839
## - V28   1   15.2563  97.868 71.013
## - V52   1   16.4743  99.086 73.140
## - V51   1   17.4832 100.095 74.883
## - V80   1   17.5866 100.198 75.061
## - V1    1   17.6163 100.228 75.111
## - V39   1   23.7327 106.344 85.300
## 
## Step:  AIC=42.16
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V10 + V11 + V12 + 
##     V13 + V14 + V15 + V16 + V17 + V19 + V21 + V22 + V23 + V24 + 
##     V25 + V26 + V27 + V28 + V29 + V30 + V31 + V32 + V33 + V34 + 
##     V35 + V36 + V37 + V39 + V40 + V41 + V42 + V43 + V44 + V45 + 
##     V46 + V48 + V49 + V50 + V51 + V52 + V53 + V55 + V56 + V58 + 
##     V59 + V60 + V61 + V62 + V63 + V64 + V65 + V66 + V68 + V69 + 
##     V70 + V72 + V73 + V74 + V77 + V78 + V79 + V80 + V81 + V82 + 
##     V83 + V84 + V85 + V86 + V87 + V92 + V93 + V94 + V96 + V97 + 
##     V98 + V99
## 
##        Df Sum of Sq     RSS    AIC
## - V33   1    0.1246  82.879 40.420
## - V49   1    0.1466  82.901 40.466
## - V86   1    0.1518  82.906 40.477
## - V58   1    0.2226  82.977 40.624
## - V65   1    0.3051  83.059 40.795
## - V94   1    0.3963  83.151 40.983
## - V11   1    0.4214  83.176 41.035
## - V34   1    0.4246  83.179 41.042
## - V98   1    0.5054  83.260 41.209
## - V3    1    0.5279  83.282 41.255
## - V48   1    0.5735  83.328 41.349
## - V56   1    0.5774  83.332 41.357
## - V35   1    0.6568  83.411 41.521
## - V93   1    0.7110  83.465 41.633
## - V12   1    0.7784  83.533 41.772
## - V10   1    0.8211  83.575 41.860
## <none>               82.754 42.162
## - V70   1    1.0525  83.807 42.335
## - V66   1    1.1725  83.927 42.581
## - V27   1    1.2139  83.968 42.666
## - V36   1    1.2465  84.001 42.733
## - V62   1    1.2690  84.023 42.779
## - V24   1    1.4773  84.232 43.205
## - V16   1    1.5514  84.306 43.356
## - V32   1    1.6784  84.433 43.615
## - V59   1    1.7224  84.477 43.705
## - V8    1    1.7619  84.516 43.785
## - V17   1    1.8177  84.572 43.899
## - V31   1    1.9883  84.743 44.245
## - V13   1    1.9952  84.749 44.259
## - V37   1    2.0822  84.837 44.436
## - V81   1    2.1001  84.854 44.472
## - V61   1    2.1381  84.892 44.549
## - V83   1    2.6110  85.365 45.505
## - V25   1    2.7515  85.506 45.787
## - V4    1    2.9320  85.686 46.150
## - V44   1    2.9367  85.691 46.160
## - V84   1    2.9976  85.752 46.282
## - V19   1    3.0260  85.780 46.339
## - V15   1    3.1059  85.860 46.499
## - V14   1    3.1227  85.877 46.532
## - V96   1    3.1525  85.907 46.592
## - V55   1    3.1641  85.918 46.615
## - V6    1    3.5062  86.261 47.299
## - V68   1    3.5140  86.268 47.314
## - V30   1    3.5762  86.331 47.438
## - V72   1    4.0533  86.808 48.386
## - V69   1    4.1417  86.896 48.561
## - V60   1    4.2420  86.996 48.760
## - V43   1    4.3632  87.117 48.999
## - V99   1    4.5391  87.293 49.346
## - V7    1    4.5562  87.310 49.380
## - V26   1    4.7387  87.493 49.739
## - V5    1    5.2039  87.958 50.651
## - V82   1    5.4217  88.176 51.076
## - V2    1    6.4333  89.188 53.039
## - V87   1    6.7854  89.540 53.716
## - V63   1    7.1772  89.931 54.467
## - V97   1    7.3043  90.059 54.710
## - V77   1    7.9824  90.737 56.000
## - V85   1    8.1457  90.900 56.310
## - V42   1    8.2311  90.985 56.471
## - V45   1    8.2426  90.997 56.493
## - V50   1    8.6068  91.361 57.180
## - V46   1    9.3312  92.086 58.538
## - V41   1    9.3321  92.086 58.540
## - V74   1   10.0421  92.796 59.861
## - V78   1   10.6558  93.410 60.995
## - V23   1   10.8308  93.585 61.317
## - V64   1   11.0109  93.765 61.648
## - V92   1   11.4202  94.174 62.397
## - V29   1   11.6109  94.365 62.745
## - V53   1   11.8539  94.608 63.187
## - V73   1   12.5359  95.290 64.422
## - V21   1   13.3379  96.092 65.864
## - V79   1   13.7450  96.499 66.591
## - V22   1   14.9222  97.676 68.677
## - V40   1   15.0152  97.769 68.840
## - V28   1   15.3770  98.131 69.476
## - V52   1   16.8047  99.559 71.960
## - V51   1   17.6038 100.358 73.335
## - V80   1   18.2498 101.004 74.439
## - V1    1   19.8496 102.604 77.142
## - V39   1   23.7442 106.498 83.549
## 
## Step:  AIC=40.42
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V10 + V11 + V12 + 
##     V13 + V14 + V15 + V16 + V17 + V19 + V21 + V22 + V23 + V24 + 
##     V25 + V26 + V27 + V28 + V29 + V30 + V31 + V32 + V34 + V35 + 
##     V36 + V37 + V39 + V40 + V41 + V42 + V43 + V44 + V45 + V46 + 
##     V48 + V49 + V50 + V51 + V52 + V53 + V55 + V56 + V58 + V59 + 
##     V60 + V61 + V62 + V63 + V64 + V65 + V66 + V68 + V69 + V70 + 
##     V72 + V73 + V74 + V77 + V78 + V79 + V80 + V81 + V82 + V83 + 
##     V84 + V85 + V86 + V87 + V92 + V93 + V94 + V96 + V97 + V98 + 
##     V99
## 
##        Df Sum of Sq     RSS    AIC
## - V49   1    0.1259  83.005 38.681
## - V86   1    0.1557  83.035 38.743
## - V58   1    0.1764  83.055 38.786
## - V65   1    0.3459  83.225 39.137
## - V11   1    0.3471  83.226 39.139
## - V94   1    0.4278  83.307 39.306
## - V98   1    0.4462  83.325 39.344
## - V3    1    0.4949  83.374 39.444
## - V48   1    0.5522  83.431 39.563
## - V35   1    0.6159  83.495 39.694
## - V93   1    0.6513  83.530 39.767
## - V56   1    0.6541  83.533 39.773
## - V12   1    0.8106  83.689 40.094
## <none>               82.879 40.420
## - V10   1    0.9967  83.876 40.476
## - V70   1    1.0336  83.912 40.552
## - V66   1    1.1230  84.002 40.735
## - V27   1    1.1936  84.072 40.880
## - V36   1    1.2873  84.166 41.071
## - V62   1    1.2962  84.175 41.089
## - V34   1    1.4407  84.320 41.385
## - V24   1    1.5479  84.427 41.603
## - V16   1    1.5806  84.459 41.670
## - V59   1    1.6611  84.540 41.833
## - V8    1    1.6697  84.549 41.851
## - V13   1    1.9538  84.833 42.428
## - V17   1    1.9705  84.849 42.462
## - V61   1    2.0550  84.934 42.633
## - V37   1    2.0849  84.964 42.694
## - V81   1    2.1439  85.023 42.813
## - V31   1    2.3722  85.251 43.274
## - V83   1    2.6439  85.523 43.822
## - V25   1    2.6623  85.541 43.859
## - V4    1    2.8464  85.725 44.228
## - V19   1    2.9209  85.800 44.378
## - V84   1    2.9407  85.820 44.417
## - V14   1    3.0447  85.924 44.626
## - V15   1    3.0469  85.926 44.630
## - V96   1    3.0522  85.931 44.641
## - V44   1    3.0996  85.978 44.736
## - V55   1    3.2511  86.130 45.038
## - V6    1    3.4503  86.329 45.436
## - V68   1    3.5788  86.458 45.692
## - V30   1    3.7133  86.592 45.959
## - V32   1    3.9628  86.842 46.454
## - V60   1    4.1685  87.047 46.861
## - V69   1    4.2269  87.106 46.976
## - V43   1    4.4376  87.316 47.392
## - V7    1    4.4545  87.333 47.425
## - V72   1    4.4681  87.347 47.452
## - V26   1    4.6806  87.559 47.870
## - V99   1    4.8505  87.729 48.203
## - V5    1    5.1060  87.985 48.703
## - V82   1    5.4037  88.283 49.284
## - V2    1    6.6865  89.565 51.765
## - V87   1    6.7508  89.630 51.889
## - V63   1    7.0603  89.939 52.482
## - V97   1    7.1806  90.059 52.712
## - V85   1    8.0709  90.950 54.404
## - V77   1    8.2433  91.122 54.729
## - V42   1    8.2825  91.161 54.804
## - V50   1    8.4840  91.363 55.183
## - V45   1    8.6455  91.524 55.487
## - V41   1    9.3953  92.274 56.890
## - V46   1    9.4495  92.328 56.991
## - V78   1   10.5446  93.423 59.019
## - V23   1   10.7782  93.657 59.449
## - V74   1   10.8479  93.727 59.577
## - V64   1   11.0131  93.892 59.880
## - V92   1   11.3145  94.193 60.431
## - V29   1   11.7474  94.626 61.220
## - V53   1   11.9038  94.783 61.504
## - V21   1   13.2449  96.124 63.920
## - V73   1   13.4256  96.304 64.243
## - V79   1   13.6235  96.502 64.597
## - V22   1   14.8151  97.694 66.707
## - V40   1   15.1785  98.057 67.346
## - V28   1   15.2559  98.135 67.482
## - V52   1   16.7912  99.670 70.152
## - V51   1   17.4863 100.365 71.347
## - V80   1   18.2654 101.144 72.677
## - V1    1   20.2683 103.147 76.050
## - V39   1   24.0723 106.951 82.279
## 
## Step:  AIC=38.68
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V10 + V11 + V12 + 
##     V13 + V14 + V15 + V16 + V17 + V19 + V21 + V22 + V23 + V24 + 
##     V25 + V26 + V27 + V28 + V29 + V30 + V31 + V32 + V34 + V35 + 
##     V36 + V37 + V39 + V40 + V41 + V42 + V43 + V44 + V45 + V46 + 
##     V48 + V50 + V51 + V52 + V53 + V55 + V56 + V58 + V59 + V60 + 
##     V61 + V62 + V63 + V64 + V65 + V66 + V68 + V69 + V70 + V72 + 
##     V73 + V74 + V77 + V78 + V79 + V80 + V81 + V82 + V83 + V84 + 
##     V85 + V86 + V87 + V92 + V93 + V94 + V96 + V97 + V98 + V99
## 
##        Df Sum of Sq     RSS    AIC
## - V86   1    0.1133  83.118 36.916
## - V58   1    0.1727  83.177 37.039
## - V11   1    0.3331  83.338 37.370
## - V65   1    0.3838  83.388 37.475
## - V94   1    0.4256  83.430 37.561
## - V3    1    0.5315  83.536 37.779
## - V98   1    0.6043  83.609 37.929
## - V93   1    0.6091  83.614 37.939
## - V35   1    0.6523  83.657 38.028
## - V12   1    0.7811  83.786 38.292
## - V56   1    0.8090  83.814 38.350
## <none>               83.005 38.681
## - V10   1    1.0309  84.036 38.804
## - V66   1    1.1298  84.134 39.007
## - V27   1    1.2448  84.250 39.242
## - V70   1    1.2660  84.271 39.285
## - V36   1    1.2833  84.288 39.320
## - V62   1    1.2878  84.293 39.329
## - V34   1    1.3704  84.375 39.498
## - V24   1    1.4518  84.457 39.664
## - V16   1    1.5224  84.527 39.807
## - V59   1    1.6688  84.673 40.105
## - V8    1    1.7070  84.712 40.183
## - V13   1    1.8709  84.876 40.515
## - V17   1    1.9430  84.948 40.661
## - V37   1    2.1469  85.152 41.073
## - V61   1    2.1671  85.172 41.114
## - V81   1    2.3607  85.365 41.505
## - V83   1    2.5440  85.549 41.874
## - V31   1    2.5915  85.596 41.969
## - V19   1    2.7951  85.800 42.378
## - V4    1    2.9017  85.906 42.592
## - V14   1    2.9440  85.949 42.676
## - V84   1    2.9810  85.986 42.750
## - V15   1    2.9813  85.986 42.751
## - V25   1    3.0935  86.098 42.975
## - V96   1    3.2302  86.235 43.248
## - V44   1    3.2316  86.236 43.251
## - V48   1    3.2616  86.266 43.310
## - V55   1    3.5213  86.526 43.827
## - V6    1    3.5872  86.592 43.958
## - V32   1    4.0355  87.040 44.847
## - V68   1    4.0708  87.076 44.916
## - V60   1    4.1283  87.133 45.030
## - V72   1    4.3454  87.350 45.458
## - V30   1    4.3556  87.360 45.478
## - V43   1    4.4183  87.423 45.602
## - V7    1    4.6056  87.610 45.970
## - V69   1    4.7090  87.714 46.172
## - V99   1    4.7309  87.736 46.215
## - V26   1    4.9110  87.916 46.568
## - V5    1    5.2263  88.231 47.184
## - V82   1    5.2881  88.293 47.304
## - V2    1    6.5783  89.583 49.800
## - V63   1    7.3681  90.373 51.309
## - V87   1    7.4118  90.417 51.392
## - V85   1    7.9730  90.978 52.457
## - V97   1    7.9817  90.986 52.473
## - V77   1    8.1284  91.133 52.750
## - V42   1    8.1818  91.187 52.851
## - V45   1    9.1176  92.122 54.607
## - V41   1    9.2760  92.281 54.903
## - V46   1   10.3192  93.324 56.836
## - V78   1   10.5794  93.584 57.315
## - V23   1   10.6719  93.677 57.485
## - V74   1   10.7293  93.734 57.590
## - V92   1   11.2119  94.217 58.474
## - V64   1   11.2127  94.217 58.475
## - V53   1   12.0207  95.025 59.944
## - V21   1   13.1268  96.132 61.934
## - V29   1   13.2360  96.241 62.130
## - V73   1   13.3302  96.335 62.298
## - V79   1   13.6008  96.606 62.780
## - V50   1   13.8420  96.847 63.209
## - V22   1   14.7432  97.748 64.802
## - V40   1   15.0671  98.072 65.371
## - V28   1   15.7750  98.780 66.609
## - V52   1   16.7003  99.705 68.212
## - V51   1   17.8794 100.884 70.234
## - V80   1   18.3040 101.309 70.957
## - V1    1   20.1702 103.175 74.096
## - V39   1   24.1059 107.111 80.535
## 
## Step:  AIC=36.92
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V10 + V11 + V12 + 
##     V13 + V14 + V15 + V16 + V17 + V19 + V21 + V22 + V23 + V24 + 
##     V25 + V26 + V27 + V28 + V29 + V30 + V31 + V32 + V34 + V35 + 
##     V36 + V37 + V39 + V40 + V41 + V42 + V43 + V44 + V45 + V46 + 
##     V48 + V50 + V51 + V52 + V53 + V55 + V56 + V58 + V59 + V60 + 
##     V61 + V62 + V63 + V64 + V65 + V66 + V68 + V69 + V70 + V72 + 
##     V73 + V74 + V77 + V78 + V79 + V80 + V81 + V82 + V83 + V84 + 
##     V85 + V87 + V92 + V93 + V94 + V96 + V97 + V98 + V99
## 
##        Df Sum of Sq     RSS     AIC
## - V58   1     0.178  83.296  35.284
## - V65   1     0.363  83.481  35.666
## - V11   1     0.383  83.501  35.707
## - V94   1     0.505  83.623  35.957
## - V93   1     0.535  83.653  36.019
## - V3    1     0.596  83.714  36.144
## - V98   1     0.604  83.722  36.161
## - V35   1     0.619  83.737  36.192
## - V12   1     0.715  83.833  36.390
## - V56   1     0.891  84.010  36.751
## <none>               83.118  36.916
## - V10   1     1.060  84.178  37.095
## - V66   1     1.123  84.241  37.224
## - V36   1     1.207  84.325  37.395
## - V70   1     1.333  84.451  37.653
## - V27   1     1.378  84.496  37.745
## - V34   1     1.417  84.535  37.823
## - V62   1     1.464  84.582  37.920
## - V24   1     1.558  84.676  38.110
## - V16   1     1.667  84.785  38.330
## - V8    1     1.678  84.796  38.353
## - V59   1     1.813  84.931  38.627
## - V13   1     1.819  84.937  38.638
## - V17   1     1.909  85.027  38.821
## - V37   1     2.062  85.180  39.131
## - V61   1     2.136  85.254  39.281
## - V81   1     2.274  85.392  39.558
## - V31   1     2.601  85.719  40.215
## - V19   1     2.841  85.959  40.696
## - V15   1     2.877  85.995  40.769
## - V14   1     2.894  86.012  40.803
## - V25   1     2.991  86.110  40.998
## - V83   1     3.053  86.171  41.120
## - V84   1     3.134  86.252  41.282
## - V4    1     3.233  86.351  41.479
## - V44   1     3.243  86.361  41.499
## - V48   1     3.383  86.501  41.778
## - V96   1     3.681  86.799  42.369
## - V55   1     3.764  86.882  42.533
## - V6    1     3.815  86.933  42.634
## - V32   1     4.075  87.193  43.148
## - V68   1     4.095  87.213  43.187
## - V60   1     4.203  87.321  43.400
## - V30   1     4.268  87.386  43.529
## - V72   1     4.436  87.554  43.858
## - V43   1     4.531  87.649  44.046
## - V69   1     4.756  87.874  44.487
## - V26   1     4.822  87.940  44.615
## - V7    1     4.832  87.950  44.636
## - V99   1     4.876  87.994  44.721
## - V5    1     5.555  88.673  46.042
## - V82   1     6.201  89.319  47.292
## - V2    1     6.649  89.767  48.152
## - V63   1     7.284  90.402  49.365
## - V77   1     8.035  91.153  50.787
## - V42   1     8.283  91.401  51.256
## - V97   1     8.524  91.642  51.709
## - V45   1     9.150  92.268  52.879
## - V41   1     9.228  92.346  53.024
## - V78   1    10.479  93.597  55.338
## - V23   1    10.642  93.760  55.638
## - V74   1    10.672  93.790  55.693
## - V46   1    10.786  93.904  55.902
## - V92   1    11.103  94.221  56.482
## - V64   1    11.157  94.275  56.580
## - V53   1    12.331  95.449  58.709
## - V21   1    13.047  96.165  59.994
## - V29   1    13.131  96.249  60.145
## - V79   1    13.765  96.883  61.273
## - V73   1    13.776  96.894  61.294
## - V50   1    14.170  97.288  61.991
## - V22   1    14.639  97.757  62.818
## - V40   1    14.979  98.098  63.416
## - V28   1    15.983  99.101  65.167
## - V52   1    16.593  99.711  66.222
## - V51   1    18.269 101.387  69.089
## - V80   1    18.790 101.908  69.972
## - V1    1    20.178 103.296  72.297
## - V85   1    20.223 103.341  72.372
## - V39   1    24.054 107.172  78.633
## - V87   1    48.019 131.137 113.345
## 
## Step:  AIC=35.28
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V10 + V11 + V12 + 
##     V13 + V14 + V15 + V16 + V17 + V19 + V21 + V22 + V23 + V24 + 
##     V25 + V26 + V27 + V28 + V29 + V30 + V31 + V32 + V34 + V35 + 
##     V36 + V37 + V39 + V40 + V41 + V42 + V43 + V44 + V45 + V46 + 
##     V48 + V50 + V51 + V52 + V53 + V55 + V56 + V59 + V60 + V61 + 
##     V62 + V63 + V64 + V65 + V66 + V68 + V69 + V70 + V72 + V73 + 
##     V74 + V77 + V78 + V79 + V80 + V81 + V82 + V83 + V84 + V85 + 
##     V87 + V92 + V93 + V94 + V96 + V97 + V98 + V99
## 
##        Df Sum of Sq     RSS     AIC
## - V11   1     0.304  83.600  33.910
## - V65   1     0.348  83.644  34.002
## - V98   1     0.468  83.764  34.248
## - V94   1     0.481  83.777  34.275
## - V93   1     0.558  83.854  34.432
## - V35   1     0.599  83.895  34.516
## - V3    1     0.718  84.014  34.761
## - V12   1     0.773  84.069  34.874
## <none>               83.296  35.284
## - V10   1     1.177  84.473  35.697
## - V56   1     1.234  84.530  35.813
## - V36   1     1.257  84.553  35.859
## - V66   1     1.268  84.564  35.882
## - V70   1     1.298  84.594  35.943
## - V34   1     1.442  84.738  36.235
## - V27   1     1.525  84.821  36.404
## - V24   1     1.555  84.851  36.466
## - V16   1     1.754  85.050  36.868
## - V13   1     1.787  85.083  36.935
## - V17   1     1.854  85.150  37.070
## - V8    1     1.881  85.177  37.124
## - V62   1     1.946  85.242  37.257
## - V61   1     2.066  85.362  37.498
## - V37   1     2.473  85.769  38.317
## - V31   1     2.575  85.871  38.521
## - V81   1     2.577  85.873  38.524
## - V25   1     2.829  86.125  39.029
## - V15   1     2.837  86.133  39.045
## - V14   1     2.852  86.148  39.075
## - V59   1     2.931  86.227  39.231
## - V84   1     2.964  86.260  39.298
## - V19   1     2.998  86.294  39.365
## - V44   1     3.335  86.631  40.036
## - V48   1     3.385  86.682  40.136
## - V4    1     3.401  86.697  40.167
## - V96   1     3.510  86.806  40.382
## - V83   1     3.711  87.007  40.781
## - V55   1     3.727  87.023  40.813
## - V6    1     3.818  87.114  40.992
## - V30   1     4.145  87.441  41.637
## - V32   1     4.149  87.445  41.645
## - V60   1     4.226  87.522  41.796
## - V68   1     4.297  87.593  41.935
## - V43   1     4.644  87.941  42.617
## - V26   1     4.659  87.955  42.644
## - V7    1     4.913  88.209  43.140
## - V72   1     4.920  88.216  43.155
## - V69   1     4.925  88.221  43.165
## - V99   1     5.345  88.641  43.982
## - V5    1     5.677  88.973  44.625
## - V2    1     6.554  89.850  46.311
## - V82   1     6.605  89.901  46.409
## - V63   1     7.106  90.402  47.365
## - V77   1     7.896  91.192  48.862
## - V42   1     8.525  91.821  50.043
## - V97   1     8.774  92.070  50.509
## - V41   1     9.208  92.504  51.318
## - V45   1    10.045  93.341  52.868
## - V23   1    10.508  93.804  53.718
## - V78   1    10.619  93.915  53.922
## - V64   1    11.209  94.505  54.999
## - V92   1    11.266  94.562  55.102
## - V74   1    11.463  94.759  55.461
## - V53   1    12.244  95.540  56.873
## - V46   1    12.290  95.586  56.956
## - V29   1    12.956  96.252  58.151
## - V21   1    13.382  96.678  58.909
## - V73   1    14.108  97.404  60.196
## - V50   1    14.187  97.483  60.335
## - V79   1    14.187  97.483  60.336
## - V22   1    14.694  97.990  61.229
## - V40   1    14.844  98.140  61.491
## - V28   1    15.826  99.122  63.203
## - V52   1    16.814 100.110  64.909
## - V51   1    18.735 102.031  68.179
## - V85   1    20.083 103.379  70.436
## - V1    1    20.725 104.021  71.501
## - V80   1    21.272 104.568  72.403
## - V39   1    24.357 107.653  77.403
## - V87   1    52.981 136.277 117.958
## 
## Step:  AIC=33.91
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V10 + V12 + V13 + 
##     V14 + V15 + V16 + V17 + V19 + V21 + V22 + V23 + V24 + V25 + 
##     V26 + V27 + V28 + V29 + V30 + V31 + V32 + V34 + V35 + V36 + 
##     V37 + V39 + V40 + V41 + V42 + V43 + V44 + V45 + V46 + V48 + 
##     V50 + V51 + V52 + V53 + V55 + V56 + V59 + V60 + V61 + V62 + 
##     V63 + V64 + V65 + V66 + V68 + V69 + V70 + V72 + V73 + V74 + 
##     V77 + V78 + V79 + V80 + V81 + V82 + V83 + V84 + V85 + V87 + 
##     V92 + V93 + V94 + V96 + V97 + V98 + V99
## 
##        Df Sum of Sq     RSS     AIC
## - V65   1     0.241  83.841  32.406
## - V93   1     0.413  84.013  32.759
## - V98   1     0.471  84.071  32.877
## - V94   1     0.584  84.184  33.108
## - V35   1     0.720  84.320  33.385
## - V3    1     0.858  84.458  33.666
## <none>               83.600  33.910
## - V36   1     1.136  84.736  34.232
## - V34   1     1.200  84.800  34.361
## - V70   1     1.291  84.891  34.547
## - V27   1     1.398  84.998  34.763
## - V56   1     1.508  85.108  34.985
## - V16   1     1.559  85.159  35.089
## - V66   1     1.768  85.368  35.510
## - V17   1     1.878  85.478  35.732
## - V62   1     1.909  85.509  35.794
## - V24   1     1.960  85.560  35.896
## - V61   1     2.077  85.677  36.131
## - V8    1     2.149  85.749  36.276
## - V37   1     2.317  85.917  36.612
## - V31   1     2.421  86.020  36.820
## - V25   1     2.549  86.149  37.077
## - V81   1     2.727  86.327  37.432
## - V84   1     2.731  86.331  37.439
## - V19   1     2.935  86.535  37.846
## - V48   1     3.243  86.843  38.457
## - V44   1     3.251  86.851  38.473
## - V96   1     3.375  86.975  38.718
## - V59   1     3.710  87.310  39.379
## - V32   1     3.867  87.467  39.688
## - V4    1     3.942  87.542  39.836
## - V83   1     4.042  87.641  40.031
## - V30   1     4.086  87.686  40.119
## - V10   1     4.142  87.742  40.228
## - V15   1     4.315  87.915  40.566
## - V13   1     4.339  87.939  40.615
## - V55   1     4.341  87.941  40.618
## - V6    1     4.366  87.966  40.666
## - V43   1     4.428  88.028  40.788
## - V26   1     4.489  88.089  40.906
## - V60   1     4.886  88.486  41.681
## - V14   1     4.914  88.514  41.734
## - V99   1     5.110  88.710  42.115
## - V72   1     5.170  88.770  42.231
## - V68   1     5.212  88.812  42.314
## - V69   1     5.314  88.914  42.511
## - V7    1     5.630  89.230  43.120
## - V12   1     5.702  89.302  43.258
## - V82   1     6.526  90.126  44.839
## - V5    1     6.596  90.196  44.973
## - V2    1     6.597  90.197  44.973
## - V63   1     7.010  90.610  45.760
## - V77   1     8.190  91.790  47.986
## - V42   1     8.281  91.880  48.155
## - V97   1     8.501  92.101  48.568
## - V41   1     8.951  92.551  49.405
## - V45   1    10.248  93.848  51.799
## - V78   1    10.491  94.091  52.244
## - V64   1    10.933  94.533  53.050
## - V92   1    11.193  94.793  53.522
## - V74   1    11.408  95.008  53.913
## - V23   1    11.428  95.028  53.948
## - V46   1    12.294  95.894  55.509
## - V29   1    12.759  96.359  56.341
## - V53   1    13.912  97.512  58.386
## - V73   1    14.001  97.601  58.543
## - V21   1    14.124  97.724  58.760
## - V50   1    14.183  97.783  58.864
## - V79   1    14.496  98.096  59.414
## - V40   1    14.541  98.141  59.492
## - V28   1    15.532  99.132  61.221
## - V22   1    15.749  99.349  61.598
## - V52   1    18.325 101.925  65.999
## - V51   1    19.332 102.932  67.691
## - V85   1    19.785 103.385  68.447
## - V1    1    21.586 105.186  71.416
## - V80   1    21.807 105.407  71.778
## - V39   1    24.054 107.654  75.405
## - V87   1    52.961 136.561 116.315
## 
## Step:  AIC=32.41
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V10 + V12 + V13 + 
##     V14 + V15 + V16 + V17 + V19 + V21 + V22 + V23 + V24 + V25 + 
##     V26 + V27 + V28 + V29 + V30 + V31 + V32 + V34 + V35 + V36 + 
##     V37 + V39 + V40 + V41 + V42 + V43 + V44 + V45 + V46 + V48 + 
##     V50 + V51 + V52 + V53 + V55 + V56 + V59 + V60 + V61 + V62 + 
##     V63 + V64 + V66 + V68 + V69 + V70 + V72 + V73 + V74 + V77 + 
##     V78 + V79 + V80 + V81 + V82 + V83 + V84 + V85 + V87 + V92 + 
##     V93 + V94 + V96 + V97 + V98 + V99
## 
##        Df Sum of Sq     RSS     AIC
## - V93   1     0.308  84.150  31.038
## - V98   1     0.489  84.330  31.406
## - V94   1     0.682  84.523  31.800
## - V35   1     0.699  84.541  31.835
## <none>               83.841  32.406
## - V3    1     1.037  84.878  32.520
## - V36   1     1.079  84.921  32.606
## - V70   1     1.148  84.989  32.744
## - V34   1     1.163  85.005  32.776
## - V16   1     1.431  85.272  33.317
## - V27   1     1.447  85.289  33.350
## - V17   1     1.799  85.641  34.058
## - V61   1     2.031  85.872  34.523
## - V8    1     2.048  85.889  34.557
## - V62   1     2.073  85.914  34.607
## - V56   1     2.263  86.104  34.987
## - V37   1     2.276  86.117  35.012
## - V25   1     2.308  86.150  35.078
## - V31   1     2.329  86.170  35.119
## - V24   1     2.364  86.206  35.190
## - V81   1     2.486  86.327  35.432
## - V84   1     2.492  86.333  35.444
## - V19   1     2.788  86.629  36.033
## - V48   1     3.006  86.848  36.466
## - V96   1     3.279  87.121  37.005
## - V44   1     3.430  87.271  37.302
## - V32   1     3.690  87.531  37.814
## - V59   1     4.098  87.939  38.613
## - V13   1     4.098  87.940  38.615
## - V30   1     4.157  87.998  38.729
## - V4    1     4.190  88.032  38.795
## - V15   1     4.403  88.244  39.210
## - V6    1     4.411  88.253  39.226
## - V26   1     4.414  88.255  39.231
## - V43   1     4.455  88.296  39.311
## - V14   1     4.699  88.540  39.786
## - V10   1     4.766  88.607  39.916
## - V99   1     4.874  88.715  40.125
## - V83   1     4.909  88.750  40.193
## - V60   1     5.129  88.970  40.619
## - V69   1     5.400  89.241  41.142
## - V12   1     5.464  89.305  41.266
## - V7    1     5.596  89.437  41.519
## - V55   1     5.977  89.818  42.250
## - V68   1     6.068  89.909  42.424
## - V2    1     6.375  90.216  43.011
## - V72   1     6.489  90.330  43.228
## - V5    1     6.780  90.621  43.782
## - V82   1     7.260  91.101  44.690
## - V63   1     8.092  91.934  46.254
## - V42   1     8.163  92.004  46.387
## - V77   1     8.187  92.028  46.432
## - V97   1     8.282  92.124  46.610
## - V41   1     8.837  92.679  47.643
## - V66   1     9.085  92.926  48.101
## - V45   1    10.661  94.503  50.995
## - V78   1    10.726  94.568  51.113
## - V92   1    11.072  94.913  51.740
## - V23   1    11.803  95.645  53.061
## - V46   1    12.321  96.162  53.989
## - V74   1    13.108  96.949  55.391
## - V29   1    13.625  97.466  56.306
## - V50   1    13.971  97.813  56.916
## - V21   1    14.049  97.890  57.052
## - V40   1    14.568  98.409  57.962
## - V79   1    14.739  98.580  58.260
## - V22   1    15.978  99.820  60.410
## - V73   1    16.771 100.612  61.770
## - V28   1    17.556 101.398  63.107
## - V53   1    17.821 101.662  63.555
## - V51   1    20.130 103.971  67.418
## - V85   1    20.931 104.773  68.739
## - V52   1    21.488 105.329  69.650
## - V1    1    21.643 105.484  69.904
## - V80   1    21.996 105.837  70.478
## - V39   1    24.186 108.027  74.001
## - V64   1    28.585 112.426  80.866
## - V87   1    55.255 139.096 117.479
## 
## Step:  AIC=31.04
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V10 + V12 + V13 + 
##     V14 + V15 + V16 + V17 + V19 + V21 + V22 + V23 + V24 + V25 + 
##     V26 + V27 + V28 + V29 + V30 + V31 + V32 + V34 + V35 + V36 + 
##     V37 + V39 + V40 + V41 + V42 + V43 + V44 + V45 + V46 + V48 + 
##     V50 + V51 + V52 + V53 + V55 + V56 + V59 + V60 + V61 + V62 + 
##     V63 + V64 + V66 + V68 + V69 + V70 + V72 + V73 + V74 + V77 + 
##     V78 + V79 + V80 + V81 + V82 + V83 + V84 + V85 + V87 + V92 + 
##     V94 + V96 + V97 + V98 + V99
## 
##        Df Sum of Sq     RSS     AIC
## - V98   1     0.361  84.510  29.773
## - V35   1     0.663  84.813  30.388
## - V36   1     0.965  85.115  31.000
## <none>               84.150  31.038
## - V34   1     1.069  85.218  31.208
## - V70   1     1.095  85.245  31.261
## - V16   1     1.165  85.315  31.403
## - V3    1     1.212  85.362  31.498
## - V27   1     1.272  85.422  31.619
## - V17   1     1.617  85.766  32.311
## - V8    1     1.853  86.003  32.785
## - V56   1     2.137  86.286  33.350
## - V25   1     2.159  86.309  33.396
## - V62   1     2.171  86.321  33.419
## - V31   1     2.187  86.337  33.451
## - V24   1     2.297  86.447  33.670
## - V37   1     2.297  86.447  33.671
## - V61   1     2.400  86.550  33.875
## - V84   1     2.524  86.674  34.120
## - V81   1     2.817  86.967  34.701
## - V19   1     2.935  87.085  34.935
## - V44   1     3.223  87.373  35.503
## - V48   1     3.307  87.457  35.668
## - V32   1     3.489  87.639  36.025
## - V30   1     4.019  88.168  37.062
## - V26   1     4.189  88.339  37.394
## - V13   1     4.367  88.517  37.740
## - V43   1     4.392  88.542  37.788
## - V4    1     4.433  88.582  37.868
## - V6    1     4.501  88.651  38.000
## - V10   1     4.665  88.814  38.317
## - V83   1     4.727  88.877  38.438
## - V59   1     4.899  89.048  38.770
## - V14   1     5.229  89.379  39.407
## - V15   1     5.345  89.495  39.630
## - V96   1     5.364  89.514  39.666
## - V7    1     5.414  89.564  39.763
## - V12   1     5.602  89.752  40.124
## - V69   1     5.623  89.773  40.163
## - V55   1     5.752  89.902  40.410
## - V99   1     5.832  89.982  40.564
## - V2    1     6.144  90.294  41.159
## - V68   1     6.363  90.513  41.576
## - V60   1     6.554  90.704  41.938
## - V72   1     6.729  90.879  42.270
## - V5    1     6.963  91.113  42.712
## - V82   1     6.989  91.138  42.760
## - V63   1     8.055  92.205  44.761
## - V77   1     8.141  92.290  44.920
## - V42   1     8.248  92.397  45.120
## - V97   1     8.495  92.645  45.580
## - V41   1     8.997  93.147  46.510
## - V66   1     9.535  93.684  47.499
## - V45   1    10.373  94.523  49.032
## - V78   1    10.608  94.758  49.459
## - V23   1    11.679  95.829  51.392
## - V46   1    12.351  96.501  52.594
## - V94   1    13.018  97.167  53.778
## - V29   1    13.561  97.710  54.736
## - V74   1    13.711  97.861  55.001
## - V50   1    13.900  98.050  55.333
## - V21   1    14.048  98.198  55.592
## - V40   1    14.956  99.105  57.174
## - V79   1    15.150  99.299  57.511
## - V22   1    15.890 100.040  58.788
## - V73   1    16.972 101.122  60.639
## - V28   1    17.263 101.412  61.133
## - V53   1    17.513 101.663  61.557
## - V51   1    19.849 103.999  65.464
## - V85   1    20.804 104.954  67.037
## - V52   1    21.179 105.329  67.651
## - V1    1    21.362 105.512  67.949
## - V80   1    23.173 107.323  70.876
## - V39   1    25.029 109.179  73.824
## - V92   1    28.190 112.340  78.734
## - V64   1    29.006 113.156  79.978
## - V87   1    55.292 139.442 115.906
## 
## Step:  AIC=29.77
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V10 + V12 + V13 + 
##     V14 + V15 + V16 + V17 + V19 + V21 + V22 + V23 + V24 + V25 + 
##     V26 + V27 + V28 + V29 + V30 + V31 + V32 + V34 + V35 + V36 + 
##     V37 + V39 + V40 + V41 + V42 + V43 + V44 + V45 + V46 + V48 + 
##     V50 + V51 + V52 + V53 + V55 + V56 + V59 + V60 + V61 + V62 + 
##     V63 + V64 + V66 + V68 + V69 + V70 + V72 + V73 + V74 + V77 + 
##     V78 + V79 + V80 + V81 + V82 + V83 + V84 + V85 + V87 + V92 + 
##     V94 + V96 + V97 + V99
## 
##        Df Sum of Sq     RSS     AIC
## - V35   1     0.786  85.296  29.365
## <none>               84.510  29.773
## - V34   1     1.102  85.612  30.001
## - V36   1     1.131  85.642  30.061
## - V70   1     1.173  85.684  30.145
## - V16   1     1.210  85.720  30.219
## - V3    1     1.295  85.805  30.388
## - V27   1     1.462  85.972  30.723
## - V17   1     1.735  86.245  31.269
## - V8    1     1.863  86.374  31.525
## - V24   1     2.076  86.587  31.948
## - V62   1     2.095  86.605  31.985
## - V84   1     2.203  86.714  32.200
## - V56   1     2.285  86.796  32.363
## - V37   1     2.463  86.974  32.715
## - V25   1     2.529  87.039  32.845
## - V81   1     2.534  87.044  32.854
## - V31   1     2.693  87.204  33.170
## - V61   1     2.720  87.231  33.222
## - V19   1     2.949  87.459  33.672
## - V48   1     3.167  87.678  34.101
## - V44   1     3.303  87.813  34.367
## - V26   1     4.224  88.734  36.162
## - V43   1     4.298  88.808  36.305
## - V32   1     4.298  88.808  36.305
## - V10   1     4.430  88.940  36.561
## - V30   1     4.440  88.950  36.581
## - V6    1     4.458  88.969  36.616
## - V13   1     4.567  89.077  36.826
## - V4    1     4.721  89.231  37.123
## - V96   1     5.242  89.753  38.125
## - V7    1     5.253  89.763  38.145
## - V14   1     5.370  89.880  38.369
## - V15   1     5.448  89.958  38.519
## - V69   1     5.506  90.016  38.630
## - V83   1     5.605  90.115  38.818
## - V12   1     5.999  90.509  39.569
## - V59   1     6.097  90.608  39.756
## - V55   1     6.122  90.633  39.803
## - V68   1     6.249  90.759  40.043
## - V72   1     6.459  90.969  40.441
## - V2    1     6.474  90.984  40.469
## - V5    1     7.183  91.693  41.804
## - V77   1     7.851  92.361  43.052
## - V82   1     8.014  92.525  43.357
## - V42   1     8.206  92.716  43.713
## - V60   1     8.406  92.916  44.083
## - V63   1     8.585  93.095  44.414
## - V41   1     9.147  93.658  45.450
## - V66   1     9.674  94.185  46.416
## - V78   1    10.298  94.808  47.550
## - V45   1    11.301  95.812  49.361
## - V23   1    11.329  95.839  49.410
## - V94   1    12.682  97.193  51.822
## - V46   1    13.203  97.713  52.741
## - V74   1    13.450  97.960  53.175
## - V21   1    13.893  98.403  53.952
## - V29   1    13.966  98.476  54.079
## - V50   1    14.109  98.619  54.329
## - V79   1    14.880  99.391  55.669
## - V40   1    15.506 100.016  56.748
## - V22   1    15.565 100.075  56.850
## - V97   1    15.738 100.249  57.147
## - V73   1    16.612 101.122  58.640
## - V28   1    17.724 102.235  60.522
## - V53   1    19.316 103.826  63.178
## - V85   1    20.513 105.023  65.150
## - V51   1    21.206 105.717  66.282
## - V1    1    22.536 107.047  68.432
## - V80   1    23.007 107.517  69.187
## - V52   1    23.490 108.001  69.959
## - V39   1    26.252 110.762  74.301
## - V92   1    27.882 112.392  76.814
## - V64   1    29.853 114.364  79.805
## - V99   1    32.735 117.245  84.085
## - V87   1    54.956 139.466 113.936
## 
## Step:  AIC=29.36
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V10 + V12 + V13 + 
##     V14 + V15 + V16 + V17 + V19 + V21 + V22 + V23 + V24 + V25 + 
##     V26 + V27 + V28 + V29 + V30 + V31 + V32 + V34 + V36 + V37 + 
##     V39 + V40 + V41 + V42 + V43 + V44 + V45 + V46 + V48 + V50 + 
##     V51 + V52 + V53 + V55 + V56 + V59 + V60 + V61 + V62 + V63 + 
##     V64 + V66 + V68 + V69 + V70 + V72 + V73 + V74 + V77 + V78 + 
##     V79 + V80 + V81 + V82 + V83 + V84 + V85 + V87 + V92 + V94 + 
##     V96 + V97 + V99
## 
##        Df Sum of Sq     RSS     AIC
## - V36   1     0.431  85.727  28.232
## - V16   1     0.935  86.231  29.240
## <none>               85.296  29.365
## - V70   1     1.165  86.461  29.698
## - V3    1     1.297  86.593  29.960
## - V17   1     1.456  86.752  30.276
## - V27   1     1.617  86.913  30.596
## - V8    1     2.101  87.397  31.551
## - V31   1     2.142  87.438  31.632
## - V24   1     2.208  87.504  31.760
## - V37   1     2.247  87.543  31.837
## - V81   1     2.407  87.703  32.151
## - V25   1     2.531  87.827  32.394
## - V84   1     2.584  87.880  32.499
## - V62   1     2.682  87.978  32.689
## - V44   1     2.876  88.172  33.069
## - V56   1     3.136  88.432  33.575
## - V19   1     3.331  88.627  33.953
## - V61   1     3.371  88.667  34.031
## - V48   1     3.500  88.796  34.283
## - V30   1     3.717  89.013  34.702
## - V43   1     3.837  89.133  34.933
## - V10   1     3.844  89.140  34.947
## - V26   1     4.260  89.555  35.747
## - V13   1     4.404  89.700  36.024
## - V32   1     4.538  89.834  36.281
## - V14   1     5.099  90.395  37.351
## - V4    1     5.118  90.414  37.388
## - V69   1     5.213  90.509  37.569
## - V15   1     5.221  90.517  37.584
## - V6    1     5.302  90.598  37.737
## - V83   1     5.370  90.666  37.866
## - V12   1     5.792  91.088  38.665
## - V68   1     5.931  91.227  38.928
## - V7    1     5.940  91.236  38.945
## - V72   1     6.554  91.850  40.097
## - V2    1     6.889  92.185  40.724
## - V59   1     7.027  92.323  40.981
## - V96   1     7.150  92.446  41.211
## - V55   1     7.338  92.634  41.560
## - V42   1     7.640  92.936  42.120
## - V77   1     7.742  93.038  42.309
## - V5    1     7.864  93.160  42.534
## - V82   1     8.151  93.447  43.062
## - V41   1     8.875  94.171  44.390
## - V63   1     8.997  94.293  44.612
## - V60   1     9.204  94.500  44.990
## - V66   1    10.058  95.354  46.538
## - V78   1    10.522  95.818  47.372
## - V45   1    10.773  96.069  47.823
## - V23   1    12.124  97.420  50.224
## - V94   1    12.926  98.222  51.634
## - V46   1    13.221  98.517  52.150
## - V29   1    13.313  98.609  52.311
## - V34   1    13.629  98.925  52.861
## - V74   1    14.434  99.730  54.255
## - V50   1    14.867 100.163  55.000
## - V21   1    15.244 100.540  55.646
## - V79   1    15.339 100.635  55.809
## - V40   1    16.003 101.299  56.941
## - V22   1    16.782 102.078  58.258
## - V73   1    17.605 102.901  59.639
## - V28   1    18.286 103.582  60.774
## - V97   1    19.104 104.400  62.126
## - V53   1    20.498 105.794  64.408
## - V51   1    22.115 107.411  67.018
## - V85   1    22.218 107.514  67.182
## - V1    1    22.415 107.711  67.497
## - V80   1    23.108 108.404  68.599
## - V52   1    24.435 109.731  70.692
## - V39   1    27.122 112.418  74.854
## - V92   1    27.212 112.508  74.991
## - V64   1    32.310 117.606  82.614
## - V99   1    34.459 119.755  85.729
## - V87   1    56.112 141.408 114.314
## 
## Step:  AIC=28.23
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V10 + V12 + V13 + 
##     V14 + V15 + V16 + V17 + V19 + V21 + V22 + V23 + V24 + V25 + 
##     V26 + V27 + V28 + V29 + V30 + V31 + V32 + V34 + V37 + V39 + 
##     V40 + V41 + V42 + V43 + V44 + V45 + V46 + V48 + V50 + V51 + 
##     V52 + V53 + V55 + V56 + V59 + V60 + V61 + V62 + V63 + V64 + 
##     V66 + V68 + V69 + V70 + V72 + V73 + V74 + V77 + V78 + V79 + 
##     V80 + V81 + V82 + V83 + V84 + V85 + V87 + V92 + V94 + V96 + 
##     V97 + V99
## 
##        Df Sum of Sq     RSS     AIC
## - V70   1     0.858  86.585  27.944
## - V16   1     0.993  86.720  28.212
## <none>               85.727  28.232
## - V27   1     1.353  87.080  28.926
## - V3    1     1.377  87.104  28.972
## - V17   1     1.652  87.379  29.514
## - V31   1     1.779  87.506  29.764
## - V8    1     2.238  87.966  30.666
## - V81   1     2.240  87.967  30.668
## - V25   1     2.305  88.032  30.795
## - V24   1     2.488  88.215  31.154
## - V62   1     2.682  88.409  31.530
## - V37   1     2.745  88.472  31.653
## - V44   1     2.822  88.549  31.802
## - V56   1     2.921  88.648  31.994
## - V84   1     3.146  88.873  32.430
## - V48   1     3.160  88.887  32.457
## - V61   1     3.188  88.915  32.513
## - V19   1     3.241  88.968  32.615
## - V30   1     3.391  89.118  32.905
## - V10   1     3.539  89.266  33.189
## - V43   1     4.009  89.736  34.093
## - V32   1     4.109  89.836  34.284
## - V26   1     4.304  90.031  34.658
## - V69   1     4.805  90.532  35.613
## - V13   1     4.889  90.616  35.772
## - V83   1     5.160  90.887  36.285
## - V15   1     5.355  91.082  36.654
## - V68   1     5.546  91.273  37.014
## - V14   1     5.579  91.306  37.077
## - V4    1     5.925  91.652  37.727
## - V12   1     6.272  91.999  38.377
## - V6    1     6.829  92.556  39.415
## - V59   1     7.004  92.731  39.741
## - V7    1     7.015  92.742  39.760
## - V96   1     7.086  92.813  39.891
## - V55   1     7.218  92.946  40.137
## - V2    1     7.311  93.038  40.308
## - V72   1     7.572  93.299  40.791
## - V42   1     7.632  93.359  40.901
## - V77   1     7.889  93.616  41.373
## - V82   1     8.276  94.003  42.084
## - V41   1     8.676  94.403  42.813
## - V60   1     9.077  94.805  43.543
## - V5    1     9.517  95.244  44.340
## - V63   1     9.551  95.279  44.401
## - V66   1    10.212  95.939  45.589
## - V45   1    10.541  96.268  46.179
## - V78   1    11.158  96.885  47.277
## - V23   1    12.177  97.904  49.076
## - V94   1    12.563  98.290  49.754
## - V29   1    13.012  98.739  50.537
## - V50   1    14.523 100.250  53.149
## - V46   1    14.869 100.597  53.743
## - V21   1    15.201 100.928  54.309
## - V74   1    15.317 101.044  54.507
## - V40   1    15.669 101.396  55.105
## - V22   1    16.610 102.337  56.693
## - V79   1    16.774 102.501  56.969
## - V28   1    17.864 103.591  58.788
## - V73   1    18.162 103.889  59.282
## - V34   1    18.390 104.117  59.659
## - V97   1    19.745 105.472  61.884
## - V53   1    20.368 106.095  62.896
## - V51   1    21.684 107.411  65.018
## - V80   1    23.106 108.833  67.279
## - V1    1    23.161 108.888  67.365
## - V52   1    24.028 109.755  68.730
## - V85   1    25.265 110.992  70.658
## - V39   1    26.772 112.499  72.978
## - V92   1    27.061 112.788  73.418
## - V64   1    35.670 121.397  86.071
## - V99   1    36.493 122.220  87.232
## - V87   1    59.416 145.143 116.798
## 
## Step:  AIC=27.94
## fat ~ V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V10 + V12 + V13 + 
##     V14 + V15 + V16 + V17 + V19 + V21 + V22 + V23 + V24 + V25 + 
##     V26 + V27 + V28 + V29 + V30 + V31 + V32 + V34 + V37 + V39 + 
##     V40 + V41 + V42 + V43 + V44 + V45 + V46 + V48 + V50 + V51 + 
##     V52 + V53 + V55 + V56 + V59 + V60 + V61 + V62 + V63 + V64 + 
##     V66 + V68 + V69 + V72 + V73 + V74 + V77 + V78 + V79 + V80 + 
##     V81 + V82 + V83 + V84 + V85 + V87 + V92 + V94 + V96 + V97 + 
##     V99
## 
##        Df Sum of Sq     RSS     AIC
## <none>               86.585  27.944
## - V27   1     1.211  87.795  28.332
## - V16   1     1.212  87.797  28.335
## - V3    1     1.328  87.913  28.562
## - V17   1     1.538  88.123  28.973
## - V25   1     1.798  88.383  29.480
## - V31   1     1.980  88.565  29.834
## - V8    1     2.091  88.676  30.049
## - V81   1     2.229  88.814  30.316
## - V62   1     2.286  88.871  30.427
## - V61   1     2.374  88.959  30.596
## - V84   1     2.463  89.048  30.770
## - V56   1     3.034  89.619  31.868
## - V48   1     3.085  89.670  31.967
## - V30   1     3.218  89.803  32.222
## - V37   1     3.258  89.842  32.297
## - V44   1     3.266  89.851  32.312
## - V10   1     3.764  90.349  33.264
## - V19   1     3.863  90.447  33.451
## - V24   1     3.995  90.579  33.702
## - V26   1     4.559  91.144  34.770
## - V43   1     4.565  91.150  34.783
## - V13   1     4.613  91.198  34.873
## - V32   1     4.728  91.313  35.089
## - V15   1     4.923  91.508  35.456
## - V14   1     5.269  91.854  36.106
## - V68   1     5.919  92.504  37.318
## - V12   1     6.103  92.688  37.660
## - V96   1     6.434  93.018  38.272
## - V4    1     6.434  93.019  38.272
## - V83   1     6.684  93.269  38.735
## - V69   1     6.806  93.391  38.959
## - V59   1     6.845  93.430  39.031
## - V6    1     7.022  93.607  39.357
## - V7    1     7.195  93.780  39.675
## - V2    1     7.525  94.110  40.279
## - V55   1     7.623  94.208  40.457
## - V77   1     8.285  94.869  41.661
## - V60   1     8.320  94.904  41.724
## - V42   1     8.382  94.967  41.838
## - V82   1     8.708  95.293  42.427
## - V63   1     8.764  95.349  42.528
## - V41   1     8.940  95.525  42.846
## - V5    1    10.077  96.662  44.880
## - V66   1    10.466  97.051  45.572
## - V78   1    11.331  97.916  47.097
## - V45   1    11.502  98.086  47.397
## - V94   1    11.976  98.561  48.226
## - V29   1    12.286  98.871  48.767
## - V50   1    13.699 100.284  51.208
## - V23   1    14.791 101.376  53.070
## - V40   1    15.385 101.969  54.075
## - V46   1    15.955 102.540  55.034
## - V79   1    16.728 103.313  56.326
## - V28   1    17.183 103.768  57.082
## - V21   1    17.600 104.185  57.772
## - V74   1    18.853 105.438  59.827
## - V22   1    19.074 105.659  60.188
## - V34   1    19.118 105.702  60.259
## - V97   1    19.247 105.832  60.469
## - V53   1    20.613 107.198  62.675
## - V51   1    20.827 107.412  63.018
## - V72   1    21.057 107.642  63.387
## - V80   1    22.638 109.223  65.894
## - V1    1    22.789 109.374  66.131
## - V52   1    23.419 110.004  67.120
## - V85   1    24.552 111.137  68.882
## - V73   1    25.125 111.709  69.766
## - V39   1    26.614 113.199  72.044
## - V92   1    27.172 113.756  72.889
## - V64   1    35.632 122.216  85.227
## - V99   1    37.819 124.404  88.279
## - V87   1    58.567 145.152 114.810
rmse(model2$fit,meatspec$fat[1:172])
## [1] 0.7095069
rmse(predict(model2,meatspec[173:215,]),meatspec$fat[173:215])  
## [1] 3.590245
# The model selection step removed 28 variables. Of course,
# the nominal fit got a little worse  as  it  always  will 
# when  predictors  are  removed,  but  the  actual 
# performance improved somewhat from 3.81 to 3.59. 
# Now let’s compute the PCA on the training sample 
# predictors:
library(MVA)
## Loading required package: HSAUR2
## Loading required package: tools
## 
## Attaching package: 'HSAUR2'
## The following objects are masked from 'package:faraway':
## 
##     epilepsy, toenail
meatpca <- prcomp(meatspec[1:172,-101])
summary(meatpca)
## Importance of components:
##                           PC1     PC2     PC3     PC4     PC5     PC6
## Standard deviation     5.0554 0.51114 0.28176 0.16771 0.03817 0.02457
## Proportion of Variance 0.9857 0.01008 0.00306 0.00108 0.00006 0.00002
## Cumulative Proportion  0.9857 0.99576 0.99882 0.99991 0.99996 0.99999
##                            PC7    PC8      PC9     PC10     PC11     PC12
## Standard deviation     0.01432 0.0108 0.004533 0.003432 0.002099 0.001759
## Proportion of Variance 0.00001 0.0000 0.000000 0.000000 0.000000 0.000000
## Cumulative Proportion  0.99999 1.0000 1.000000 1.000000 1.000000 1.000000
##                            PC13      PC14      PC15      PC16      PC17
## Standard deviation     0.000998 0.0007307 0.0005441 0.0004426 0.0003933
## Proportion of Variance 0.000000 0.0000000 0.0000000 0.0000000 0.0000000
## Cumulative Proportion  1.000000 1.0000000 1.0000000 1.0000000 1.0000000
##                             PC18      PC19      PC20      PC21      PC22
## Standard deviation     0.0003409 0.0002888 0.0002046 0.0001958 0.0001904
## Proportion of Variance 0.0000000 0.0000000 0.0000000 0.0000000 0.0000000
## Cumulative Proportion  1.0000000 1.0000000 1.0000000 1.0000000 1.0000000
##                             PC23      PC24      PC25      PC26      PC27
## Standard deviation     0.0001646 0.0001423 0.0001125 0.0001059 0.0001019
## Proportion of Variance 0.0000000 0.0000000 0.0000000 0.0000000 0.0000000
## Cumulative Proportion  1.0000000 1.0000000 1.0000000 1.0000000 1.0000000
##                             PC28      PC29      PC30      PC31      PC32
## Standard deviation     9.614e-05 8.896e-05 8.082e-05 7.738e-05 7.372e-05
## Proportion of Variance 0.000e+00 0.000e+00 0.000e+00 0.000e+00 0.000e+00
## Cumulative Proportion  1.000e+00 1.000e+00 1.000e+00 1.000e+00 1.000e+00
##                             PC33      PC34      PC35      PC36      PC37
## Standard deviation     6.861e-05 6.326e-05 5.761e-05 5.392e-05 4.801e-05
## Proportion of Variance 0.000e+00 0.000e+00 0.000e+00 0.000e+00 0.000e+00
## Cumulative Proportion  1.000e+00 1.000e+00 1.000e+00 1.000e+00 1.000e+00
##                             PC38      PC39      PC40      PC41      PC42
## Standard deviation     4.685e-05 4.418e-05 4.271e-05 3.768e-05 3.534e-05
## Proportion of Variance 0.000e+00 0.000e+00 0.000e+00 0.000e+00 0.000e+00
## Cumulative Proportion  1.000e+00 1.000e+00 1.000e+00 1.000e+00 1.000e+00
##                             PC43      PC44      PC45      PC46      PC47
## Standard deviation     3.435e-05 3.291e-05 3.117e-05 2.803e-05 2.662e-05
## Proportion of Variance 0.000e+00 0.000e+00 0.000e+00 0.000e+00 0.000e+00
## Cumulative Proportion  1.000e+00 1.000e+00 1.000e+00 1.000e+00 1.000e+00
##                             PC48      PC49      PC50     PC51      PC52
## Standard deviation     2.635e-05 2.343e-05 2.193e-05 2.14e-05 2.082e-05
## Proportion of Variance 0.000e+00 0.000e+00 0.000e+00 0.00e+00 0.000e+00
## Cumulative Proportion  1.000e+00 1.000e+00 1.000e+00 1.00e+00 1.000e+00
##                            PC53     PC54      PC55      PC56      PC57
## Standard deviation     1.95e-05 1.85e-05 1.752e-05 1.746e-05 1.633e-05
## Proportion of Variance 0.00e+00 0.00e+00 0.000e+00 0.000e+00 0.000e+00
## Cumulative Proportion  1.00e+00 1.00e+00 1.000e+00 1.000e+00 1.000e+00
##                             PC58      PC59      PC60      PC61      PC62
## Standard deviation     1.596e-05 1.552e-05 1.485e-05 1.415e-05 1.358e-05
## Proportion of Variance 0.000e+00 0.000e+00 0.000e+00 0.000e+00 0.000e+00
## Cumulative Proportion  1.000e+00 1.000e+00 1.000e+00 1.000e+00 1.000e+00
##                             PC63      PC64      PC65      PC66      PC67
## Standard deviation     1.275e-05 1.256e-05 1.231e-05 1.158e-05 1.131e-05
## Proportion of Variance 0.000e+00 0.000e+00 0.000e+00 0.000e+00 0.000e+00
## Cumulative Proportion  1.000e+00 1.000e+00 1.000e+00 1.000e+00 1.000e+00
##                             PC68      PC69      PC70     PC71      PC72
## Standard deviation     1.092e-05 1.006e-05 9.678e-06 9.43e-06 9.144e-06
## Proportion of Variance 0.000e+00 0.000e+00 0.000e+00 0.00e+00 0.000e+00
## Cumulative Proportion  1.000e+00 1.000e+00 1.000e+00 1.00e+00 1.000e+00
##                             PC73     PC74      PC75      PC76    PC77
## Standard deviation     9.038e-06 8.83e-06 8.384e-06 8.112e-06 7.9e-06
## Proportion of Variance 0.000e+00 0.00e+00 0.000e+00 0.000e+00 0.0e+00
## Cumulative Proportion  1.000e+00 1.00e+00 1.000e+00 1.000e+00 1.0e+00
##                            PC78      PC79      PC80      PC81      PC82
## Standard deviation     7.64e-06 7.074e-06 7.007e-06 6.512e-06 6.113e-06
## Proportion of Variance 0.00e+00 0.000e+00 0.000e+00 0.000e+00 0.000e+00
## Cumulative Proportion  1.00e+00 1.000e+00 1.000e+00 1.000e+00 1.000e+00
##                             PC83      PC84      PC85      PC86      PC87
## Standard deviation     5.902e-06 5.721e-06 5.579e-06 5.047e-06 4.531e-06
## Proportion of Variance 0.000e+00 0.000e+00 0.000e+00 0.000e+00 0.000e+00
## Cumulative Proportion  1.000e+00 1.000e+00 1.000e+00 1.000e+00 1.000e+00
##                             PC88      PC89      PC90      PC91      PC92
## Standard deviation     4.399e-06 4.037e-06 3.989e-06 3.856e-06 3.664e-06
## Proportion of Variance 0.000e+00 0.000e+00 0.000e+00 0.000e+00 0.000e+00
## Cumulative Proportion  1.000e+00 1.000e+00 1.000e+00 1.000e+00 1.000e+00
##                             PC93     PC94     PC95      PC96     PC97
## Standard deviation     3.359e-06 2.81e-06 2.51e-06 2.312e-06 2.18e-06
## Proportion of Variance 0.000e+00 0.00e+00 0.00e+00 0.000e+00 0.00e+00
## Cumulative Proportion  1.000e+00 1.00e+00 1.00e+00 1.000e+00 1.00e+00
##                            PC98      PC99     PC100
## Standard deviation     1.96e-06 1.828e-06 1.546e-06
## Proportion of Variance 0.00e+00 0.000e+00 0.000e+00
## Cumulative Proportion  1.00e+00 1.000e+00 1.000e+00
str(meatpca)
## List of 5
##  $ sdev    : num [1:100] 5.0554 0.5111 0.2818 0.1677 0.0382 ...
##  $ rotation: num [1:100, 1:100] 0.0785 0.079 0.0795 0.0799 0.0804 ...
##   ..- attr(*, "dimnames")=List of 2
##   .. ..$ : chr [1:100] "V1" "V2" "V3" "V4" ...
##   .. ..$ : chr [1:100] "PC1" "PC2" "PC3" "PC4" ...
##  $ center  : Named num [1:100] 2.81 2.82 2.82 2.82 2.82 ...
##   ..- attr(*, "names")= chr [1:100] "V1" "V2" "V3" "V4" ...
##  $ scale   : logi FALSE
##  $ x       : num [1:172, 1:100] -2.245 0.442 -3.831 -1.085 0.538 ...
##   ..- attr(*, "dimnames")=List of 2
##   .. ..$ : chr [1:172] "1" "2" "3" "4" ...
##   .. ..$ : chr [1:100] "PC1" "PC2" "PC3" "PC4" ...
##  - attr(*, "class")= chr "prcomp"
round(meatpca$sdev,3)  
##   [1] 5.055 0.511 0.282 0.168 0.038 0.025 0.014 0.011 0.005 0.003 0.002
##  [12] 0.002 0.001 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000
##  [23] 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
##  [34] 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
##  [45] 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
##  [56] 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
##  [67] 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
##  [78] 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
##  [89] 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
## [100] 0.000
# It is better to examine the square roots because the
# eigenvalues themselves are the variances of the PCs, 
# but standard deviations are a better scale for comparison.
# We see that the first PC accounts for about ten times more
# variation than the second. The contribution drops off 
# sharply. This suggests that most of the variation in the
# predictors can be explained with just a few dimensions. 
# The eigenvalues can be found in the object meatpca$rotat 
# ion. We plot these vectors against the predictor number
# (which represents a range of frequencies in this case
matplot(1:100,meatpca$rotation[,1:3],type = "l",
        xlab = "Frequency",ylab = "")

# We can get the PCs themselves from the columns of the 
# object meatpca$x. Let’s use the first four PCs to predict
# the response:
model3 <- lm(fat~ meatpca$x[,1:4],meatspec[1:172,])
rmse(model3$fit,meatspec$fat[1:172])
## [1] 4.064745
# We do not expect as good a fit using only four variables
# instead of the 100. Even so, considering that, the fit
# is not much worse than the much bigger models