packages:

lapply(c("car","lmtest"),library,character.only=T)[[1]]
## Loading required package: carData
## Loading required package: zoo
## 
## Attaching package: 'zoo'
## The following objects are masked from 'package:base':
## 
##     as.Date, as.Date.numeric
## [1] "car"       "carData"   "stats"     "graphics"  "grDevices" "utils"    
## [7] "datasets"  "methods"   "base"

INPUT DATA

data <- read.csv("C:/Users/ASUS/OneDrive/Documents/sem 5/Pengantar Sains Data/heart.csv")
head(data)
##   age sex cp trestbps chol fbs restecg thalach exang oldpeak slope ca thal
## 1  52   1  0      125  212   0       1     168     0     1.0     2  2    3
## 2  53   1  0      140  203   1       0     155     1     3.1     0  0    3
## 3  70   1  0      145  174   0       1     125     1     2.6     0  0    3
## 4  61   1  0      148  203   0       1     161     0     0.0     2  1    3
## 5  62   0  0      138  294   1       1     106     0     1.9     1  3    2
## 6  58   0  0      100  248   0       0     122     0     1.0     1  0    2
##   target
## 1      0
## 2      0
## 3      0
## 4      0
## 5      0
## 6      1
str(data)
## 'data.frame':    1025 obs. of  14 variables:
##  $ age     : int  52 53 70 61 62 58 58 55 46 54 ...
##  $ sex     : int  1 1 1 1 0 0 1 1 1 1 ...
##  $ cp      : int  0 0 0 0 0 0 0 0 0 0 ...
##  $ trestbps: int  125 140 145 148 138 100 114 160 120 122 ...
##  $ chol    : int  212 203 174 203 294 248 318 289 249 286 ...
##  $ fbs     : int  0 1 0 0 1 0 0 0 0 0 ...
##  $ restecg : int  1 0 1 1 1 0 2 0 0 0 ...
##  $ thalach : int  168 155 125 161 106 122 140 145 144 116 ...
##  $ exang   : int  0 1 1 0 0 0 0 1 0 1 ...
##  $ oldpeak : num  1 3.1 2.6 0 1.9 1 4.4 0.8 0.8 3.2 ...
##  $ slope   : int  2 0 0 2 1 1 0 1 2 1 ...
##  $ ca      : int  2 0 0 1 3 0 3 1 0 2 ...
##  $ thal    : int  3 3 3 3 2 2 1 3 3 2 ...
##  $ target  : int  0 0 0 0 0 1 0 0 0 0 ...

Tipe Data Berdasarkan hasil running kode di atas, kita bisa melihat bahwa seluruh dataset merupakan variabel numerik sehingga dapat diolah. Beberapa variabel merupakan variabel kategorik yang sudah dikuantitatifkan menjadi angka. Karena itu, dilihat dari tipe datanya, dataset ini sudah siap diolah.

Memeriksa missing data

sum(is.na(data)) # total keseluruhan NA bila ada
## [1] 0
colSums(is.na(data)) # total NA per kolo
##      age      sex       cp trestbps     chol      fbs  restecg  thalach 
##        0        0        0        0        0        0        0        0 
##    exang  oldpeak    slope       ca     thal   target 
##        0        0        0        0        0        0

Tidak terdapat missing data

Identifikasi Peubah

y <- data$target
x1 <- data$age
x2 <- data$sex
x3 <- data$cp
x4 <- data$trestbps
x5 <- data$chol
x6 <- data$fbs
x7 <- data$restecg
x8 <- data$thalach
x9 <- data$exang
x10 <- data$oldpeak
x11 <- data$slope
x12 <- data$ca
x13 <- data$thal

Variables Definition

Age : It defines the age of pasien yang bersangkutan

Sex : It tells us the gender of pasien pada data set

  • 0 = female

  • 1 = male

CP : It defines whether ada nyeri pada dada dan jenis nyerinya

  • 0 = Tipe angina

  • 1 = Tipe angina anomali

  • 2 = Bukan tipe angine

  • 3 = Tidak ada nyeri

Trestbps : It shows us the bear per second (Detak jantung) saat kondisi beristirahat.

Chol : Kandungan kolesterol dalam darah

fbs : Fasting blood sugar (Gula darah ketika berpuasa jika di atas 120 = 1, maka ada indikasi gula darah tidak normal, vice versa)

restecg: resting electrocardiographic results

  • Value 0: normal

  • Value 1: having ST-T wave abnormality (T wave inversions and/or ST elevation or depression of > 0.05 mV)

  • Value 2: showing probable or definite left ventricular hypertrophy by Estes’ criteria

thalach: maximum heart rate achieved

exang: exercise induced angina atau ada sakit gak setelah exercise (1 = yes; 0 = no)

oldpeak: ST depression induced by exercise relative to rest (Kemiringan garis pada hasil tes elektrokardiogram atau EGK saat istirahat setelah melakukan exercise)

slope: the slope of the peak exercise ST segment (Jenis kemiringan pada oldpeak, dilihat dari gradiennya)

  • Value 1: upsloping

  • Value 2: flat

  • Value 3: Downsloping

ca: number of major vessels (0–3) colored by fluoroscopy (Major vessel yang diberi warna oleh fluoroscopy memiliki masalah atau tidak normal)

thal:

  • 0 = normal

  • 1 = fixed defect

  • 2 = reversable defect

ANALISIS REGRESI KLASIK

Model awal

model.awal <- lm(y~x1+x2+x3+x4+x5+x6+x7+x8+x9+x10+x11+x12+x13)
model.awal
## 
## Call:
## lm(formula = y ~ x1 + x2 + x3 + x4 + x5 + x6 + x7 + x8 + x9 + 
##     x10 + x11 + x12 + x13)
## 
## Coefficients:
## (Intercept)           x1           x2           x3           x4           x5  
##    0.879266    -0.001430    -0.210721     0.111820    -0.001818    -0.000458  
##          x6           x7           x8           x9          x10          x11  
##    0.004225     0.044308     0.002878    -0.144644    -0.061020     0.076220  
##         x12          x13  
##   -0.095612    -0.115237

Diperoleh model awal:

\[y = 0.879266 - 0.001430x_1 - 0.210721x_2 + 0.111820x_3 - 0.001818x_4 - 0.000458x_5 + 0.004225x_6 + 0.044308x_7 + 0.002878x_8 - 0.144644x_9 - 0.061020x_{10} + 0.076220x_{11} - 0.095612x_{12} - 0.115237x_{13} \]

summary(model.awal)
## 
## Call:
## lm(formula = y ~ x1 + x2 + x3 + x4 + x5 + x6 + x7 + x8 + x9 + 
##     x10 + x11 + x12 + x13)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.92108 -0.21388  0.04493  0.26507  0.95158 
## 
## Coefficients:
##               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  0.8792656  0.1578856   5.569 3.28e-08 ***
## x1          -0.0014296  0.0014432  -0.991 0.322151    
## x2          -0.2107215  0.0255809  -8.237 5.40e-16 ***
## x3           0.1118197  0.0120981   9.243  < 2e-16 ***
## x4          -0.0018183  0.0006758  -2.691 0.007247 ** 
## x5          -0.0004580  0.0002273  -2.015 0.044173 *  
## x6           0.0042250  0.0320768   0.132 0.895237    
## x7           0.0443080  0.0214084   2.070 0.038739 *  
## x8           0.0028781  0.0006051   4.756 2.26e-06 ***
## x9          -0.1446437  0.0275997  -5.241 1.95e-07 ***
## x10         -0.0610202  0.0121847  -5.008 6.49e-07 ***
## x11          0.0762203  0.0227286   3.354 0.000828 ***
## x12         -0.0956120  0.0116263  -8.224 6.02e-16 ***
## x13         -0.1152366  0.0188241  -6.122 1.32e-09 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.3505 on 1011 degrees of freedom
## Multiple R-squared:  0.5149, Adjusted R-squared:  0.5087 
## F-statistic: 82.56 on 13 and 1011 DF,  p-value: < 2.2e-16

Diperoleh nilai p-value < 2.2e-16 < 0.05 dengan nilai R-squared 50.87%.. Diketahui peubah x1 dan x6 tidak berpengaruh signifikan terhadap perubah y.

Pencilan, Leverage, Amatan Berpengaruh

library(olsrr)
## 
## Attaching package: 'olsrr'
## The following object is masked from 'package:datasets':
## 
##     rivers
ols_plot_resid_lev(model.awal)

s <- sqrt(anova(model.awal)["Residuals", "Mean Sq"])
n = dim(data)[1]
p = length(model.awal$coefficients)
hii=hatvalues(model.awal)
Obs = c(1:n)
ei = model.awal$residuals
ri = ei/(s*sqrt(1-hii))
Di = (ri^2/p)*(hii/(1-hii))
summ <- cbind.data.frame(Obs, data, hii, ri, Di)

Pendeteksian Pencilan

for (i in 1:dim(summ)[1]){
  absri <- abs(summ$ri)
  pencilan <- which(absri > 2)
}
pencilan <- as.vector(pencilan)
pencilan
##  [1]   23   39   43  112  221  266  359  362  365  392  430  457  505  522  529
## [16]  544  625  630  631  639  643  647  657  671  710  720  721  744  747  750
## [31]  760  779  806  832  844  855  862  865  875  897  914  919  925  938  939
## [46]  956  963  984  986 1004 1017

Pendeteksian Titik Leverage

for (i in 1:dim(summ)[1]){
  cutoff <- 2*p/n
  titik_leverage <- which(hii > cutoff)
}
titik_leverage<-as.vector(titik_leverage)
titik_leverage
##  [1]    7   15   30   70  151  159  176  193  211  295  357  394  465  509  510
## [16]  527  570  588  610  662  683  687  689  709  735  794  894  928  968  987
## [31] 1014
gabungan<-as.vector(sort(rbind(c(titik_leverage,pencilan))))
gabungan<-unique(gabungan)
gabungan
##  [1]    7   15   23   30   39   43   70  112  151  159  176  193  211  221  266
## [16]  295  357  359  362  365  392  394  430  457  465  505  509  510  522  527
## [31]  529  544  570  588  610  625  630  631  639  643  647  657  662  671  683
## [46]  687  689  709  710  720  721  735  744  747  750  760  779  794  806  832
## [61]  844  855  862  865  875  894  897  914  919  925  928  938  939  956  963
## [76]  968  984  986  987 1004 1014 1017

Amatan Berpengaruh

DFFITS

u<-2/sqrt(p/n)
dfft<-dffits(model.awal)
dfftabs<-abs(dfft)
dffit<-which(dfftabs>u)
dffit<-as.vector(dffit)

DFBETAS

s<-2/sqrt(n)
dfbt<-dfbetas(model.awal)
dfbtabs<-abs(dfbt)
dbts<-NULL
for(i in 1:ncol(dfbtabs)){
  dfbts<-as.vector(which(dfbtabs[,1]>s))
  dbts<-rbind(c(dbts,dfbts))
}
dbts<-as.vector(dbts)

Jarak COOK

for (i in 1:dim(summ)[1]){
  fcrit <- qf(0.95, p, n-p)
  jarakcook <- which(Di > fcrit)
}
jarakcook <- as.vector(jarakcook)

Diperoleh amatan berpengaruh:

gabungan_ab<-as.vector(rbind(c(dffit,jarakcook,dbts)))
gabungan_ab<-unique(gabungan_ab)
gabungan_ab
##  [1]    6   23   66   82  138  148  152  225  227  237  247  258  266  277  327
## [16]  350  392  415  422  430  457  460  487  505  529  601  625  630  631  639
## [31]  647  664  710  721  747  799  836  840  855  862  863  881  892  896  897
## [46]  899  902  914  938  950  952  962 1017 1019

Pencilan/Leverage yang bukan Amatan Berpengaruh

dibuang<-NULL
k<-1
for(i in 1:length(gabungan)){
  skor<-0
  cek<-gabungan[i]
  for(j in 1:length(gabungan_ab)){
    if(cek != gabungan_ab[j]){
      skor<- skor+1
      if(skor==length(gabungan_ab)){
        dibuang[k]<-cek
        k<-k+1
      }
    }
  }
}
dibuang<-unique(dibuang)
dibuang
##  [1]    7   15   30   39   43   70  112  151  159  176  193  211  221  295  357
## [16]  359  362  365  394  465  509  510  522  527  544  570  588  610  643  657
## [31]  662  671  683  687  689  709  720  735  744  750  760  779  794  806  832
## [46]  844  865  875  894  919  925  928  939  956  963  968  984  986  987 1004
## [61] 1014

Data Baru

data.baru <- data[-c(7, 15, 30, 39, 43, 70, 112, 151, 159,  176,  193,  211,  221,  295,  357,  359,  362,  365,  394,  465,  509,  510,  522,  527,  544,  570,  588,  610,  643,  657,  662,  671,  683,  687,  689,  709,  720,  735,  744,  750,  760,  779,  794,  806,  832,  844,  865,  875,  894,  919,  925,  928,  939,  956,  963,  968,  984,  986,  987, 1004, 1014),]
head(data.baru)
##   age sex cp trestbps chol fbs restecg thalach exang oldpeak slope ca thal
## 1  52   1  0      125  212   0       1     168     0     1.0     2  2    3
## 2  53   1  0      140  203   1       0     155     1     3.1     0  0    3
## 3  70   1  0      145  174   0       1     125     1     2.6     0  0    3
## 4  61   1  0      148  203   0       1     161     0     0.0     2  1    3
## 5  62   0  0      138  294   1       1     106     0     1.9     1  3    2
## 6  58   0  0      100  248   0       0     122     0     1.0     1  0    2
##   target
## 1      0
## 2      0
## 3      0
## 4      0
## 5      0
## 6      1
y.baru <- data.baru$target
x1.baru <- data.baru$age
x2.baru <- data.baru$sex
x3.baru <- data.baru$cp
x4.baru <- data.baru$trestbps
x5.baru <- data.baru$chol
x6.baru <- data.baru$fbs
x7.baru <- data.baru$restecg
x8.baru <- data.baru$thalach
x9.baru <- data.baru$exang
x10.baru <- data.baru$oldpeak
x11.baru <- data.baru$slope
x12.baru <- data.baru$ca
x13.baru <- data.baru$thal

Model Baru

Model setelah dilakukan penanganan pencilan, leverage, dan amatan berpengaruh

model.baru <- lm(y.baru ~ x1.baru+x2.baru+x3.baru+x4.baru+x5.baru+x6.baru+x7.baru+x8.baru+x9.baru+x10.baru+x11.baru+x12.baru+x13.baru)
model.baru
## 
## Call:
## lm(formula = y.baru ~ x1.baru + x2.baru + x3.baru + x4.baru + 
##     x5.baru + x6.baru + x7.baru + x8.baru + x9.baru + x10.baru + 
##     x11.baru + x12.baru + x13.baru)
## 
## Coefficients:
## (Intercept)      x1.baru      x2.baru      x3.baru      x4.baru      x5.baru  
##   0.8196897   -0.0006504   -0.2105847    0.1094563   -0.0012237   -0.0004599  
##     x6.baru      x7.baru      x8.baru      x9.baru     x10.baru     x11.baru  
##  -0.0048811    0.0305692    0.0032659   -0.1282687   -0.0472500    0.1036999  
##    x12.baru     x13.baru  
##  -0.1186849   -0.1799735

Diperoleh model baru:

\[y = 0.8196897 - 0.0006504x_1 - 0.2105847x_2 + 0.1094563x_3 - 0.0012237x_4 - 0.0004599x_5 - 0.0048811x_6 + 0.0305692x_7 + 0.0032659x_8 - 0.1282687x_9 - 0.0472500x_{10} + 0.1036999x_{11} - 0.1186849x_{12} - 0.1799735x_{13} \]

summary(model.baru)
## 
## Call:
## lm(formula = y.baru ~ x1.baru + x2.baru + x3.baru + x4.baru + 
##     x5.baru + x6.baru + x7.baru + x8.baru + x9.baru + x10.baru + 
##     x11.baru + x12.baru + x13.baru)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.92797 -0.20641  0.04604  0.23749  0.70771 
## 
## Coefficients:
##               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  0.8196897  0.1507743   5.437 6.91e-08 ***
## x1.baru     -0.0006504  0.0013598  -0.478   0.6325    
## x2.baru     -0.2105847  0.0246468  -8.544  < 2e-16 ***
## x3.baru      0.1094563  0.0116323   9.410  < 2e-16 ***
## x4.baru     -0.0012237  0.0006721  -1.821   0.0689 .  
## x5.baru     -0.0004599  0.0002311  -1.990   0.0469 *  
## x6.baru     -0.0048811  0.0317004  -0.154   0.8777    
## x7.baru      0.0305692  0.0212509   1.438   0.1506    
## x8.baru      0.0032659  0.0006029   5.417 7.69e-08 ***
## x9.baru     -0.1282687  0.0263021  -4.877 1.26e-06 ***
## x10.baru    -0.0472500  0.0119915  -3.940 8.73e-05 ***
## x11.baru     0.1036999  0.0221807   4.675 3.36e-06 ***
## x12.baru    -0.1186849  0.0115532 -10.273  < 2e-16 ***
## x13.baru    -0.1799735  0.0189454  -9.500  < 2e-16 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.3237 on 950 degrees of freedom
## Multiple R-squared:  0.5864, Adjusted R-squared:  0.5807 
## F-statistic: 103.6 on 13 and 950 DF,  p-value: < 2.2e-16

Diperoleh nilai p-value < 2.2e-16 < 0.05 dengan nilai R-squared 58.07%. Diketahui peubah x1, x4, x6 dan x7 tidak berpengaruh signifikan terhadap perubah y.

Multikolinearitas

vif(model.baru)
##  x1.baru  x2.baru  x3.baru  x4.baru  x5.baru  x6.baru  x7.baru  x8.baru 
## 1.447900 1.171099 1.306364 1.175918 1.156434 1.099799 1.097817 1.715542 
##  x9.baru x10.baru x11.baru x12.baru x13.baru 
## 1.426921 1.655015 1.653244 1.205480 1.182393

Tidak terddapat multikolinearitas (VIF < 10).

Pemilihan Peubah

ols_step_both_p(model.baru, details =TRUE)
## Stepwise Selection Method   
## ---------------------------
## 
## Candidate Terms: 
## 
## 1. x1.baru 
## 2. x2.baru 
## 3. x3.baru 
## 4. x4.baru 
## 5. x5.baru 
## 6. x6.baru 
## 7. x7.baru 
## 8. x8.baru 
## 9. x9.baru 
## 10. x10.baru 
## 11. x11.baru 
## 12. x12.baru 
## 13. x13.baru 
## 
## We are selecting variables based on p value...
## 
## 
## Stepwise Selection: Step 1 
## 
## - x9.baru added 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.460       RMSE                0.444 
## R-Squared               0.212       Coef. Var          85.435 
## Adj. R-Squared          0.211       MSE                 0.197 
## Pred R-Squared          0.209       MAE                 0.393 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                 ANOVA                                 
## ---------------------------------------------------------------------
##                Sum of                                                
##               Squares         DF    Mean Square       F         Sig. 
## ---------------------------------------------------------------------
## Regression     50.970          1         50.970    258.537    0.0000 
## Residual      189.656        962          0.197                      
## Total         240.626        963                                     
## ---------------------------------------------------------------------
## 
##                                    Parameter Estimates                                    
## -----------------------------------------------------------------------------------------
##       model      Beta    Std. Error    Std. Beta       t        Sig      lower     upper 
## -----------------------------------------------------------------------------------------
## (Intercept)     0.684         0.018                  38.906    0.000     0.650     0.719 
##     x9.baru    -0.486         0.030       -0.460    -16.079    0.000    -0.545    -0.426 
## -----------------------------------------------------------------------------------------
## 
## 
## 
## Stepwise Selection: Step 2 
## 
## - x12.baru added 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.581       RMSE                0.407 
## R-Squared               0.337       Coef. Var          78.374 
## Adj. R-Squared          0.336       MSE                 0.166 
## Pred R-Squared          0.333       MAE                 0.341 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                 ANOVA                                 
## ---------------------------------------------------------------------
##                Sum of                                                
##               Squares         DF    Mean Square       F         Sig. 
## ---------------------------------------------------------------------
## Regression     81.190          2         40.595    244.688    0.0000 
## Residual      159.435        961          0.166                      
## Total         240.626        963                                     
## ---------------------------------------------------------------------
## 
##                                    Parameter Estimates                                    
## -----------------------------------------------------------------------------------------
##       model      Beta    Std. Error    Std. Beta       t        Sig      lower     upper 
## -----------------------------------------------------------------------------------------
## (Intercept)     0.794         0.018                  43.946    0.000     0.759     0.830 
##     x9.baru    -0.428         0.028       -0.406    -15.265    0.000    -0.483    -0.373 
##    x12.baru    -0.181         0.013       -0.359    -13.496    0.000    -0.207    -0.155 
## -----------------------------------------------------------------------------------------
## 
## 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.581       RMSE                0.407 
## R-Squared               0.337       Coef. Var          78.374 
## Adj. R-Squared          0.336       MSE                 0.166 
## Pred R-Squared          0.333       MAE                 0.341 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                 ANOVA                                 
## ---------------------------------------------------------------------
##                Sum of                                                
##               Squares         DF    Mean Square       F         Sig. 
## ---------------------------------------------------------------------
## Regression     81.190          2         40.595    244.688    0.0000 
## Residual      159.435        961          0.166                      
## Total         240.626        963                                     
## ---------------------------------------------------------------------
## 
##                                    Parameter Estimates                                    
## -----------------------------------------------------------------------------------------
##       model      Beta    Std. Error    Std. Beta       t        Sig      lower     upper 
## -----------------------------------------------------------------------------------------
## (Intercept)     0.794         0.018                  43.946    0.000     0.759     0.830 
##     x9.baru    -0.428         0.028       -0.406    -15.265    0.000    -0.483    -0.373 
##    x12.baru    -0.181         0.013       -0.359    -13.496    0.000    -0.207    -0.155 
## -----------------------------------------------------------------------------------------
## 
## 
## 
## Stepwise Selection: Step 3 
## 
## - x13.baru added 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.652       RMSE                0.379 
## R-Squared               0.426       Coef. Var          73.007 
## Adj. R-Squared          0.424       MSE                 0.144 
## Pred R-Squared          0.420       MAE                 0.312 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                 ANOVA                                 
## ---------------------------------------------------------------------
##                Sum of                                                
##               Squares         DF    Mean Square       F         Sig. 
## ---------------------------------------------------------------------
## Regression    102.422          3         34.141    237.152    0.0000 
## Residual      138.203        960          0.144                      
## Total         240.626        963                                     
## ---------------------------------------------------------------------
## 
##                                    Parameter Estimates                                    
## -----------------------------------------------------------------------------------------
##       model      Beta    Std. Error    Std. Beta       t        Sig      lower     upper 
## -----------------------------------------------------------------------------------------
## (Intercept)     1.356         0.049                  27.552    0.000     1.259     1.452 
##     x9.baru    -0.361         0.027       -0.342    -13.534    0.000    -0.414    -0.309 
##    x12.baru    -0.163         0.013       -0.323    -12.956    0.000    -0.188    -0.138 
##    x13.baru    -0.256         0.021       -0.307    -12.144    0.000    -0.298    -0.215 
## -----------------------------------------------------------------------------------------
## 
## 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.652       RMSE                0.379 
## R-Squared               0.426       Coef. Var          73.007 
## Adj. R-Squared          0.424       MSE                 0.144 
## Pred R-Squared          0.420       MAE                 0.312 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                 ANOVA                                 
## ---------------------------------------------------------------------
##                Sum of                                                
##               Squares         DF    Mean Square       F         Sig. 
## ---------------------------------------------------------------------
## Regression    102.422          3         34.141    237.152    0.0000 
## Residual      138.203        960          0.144                      
## Total         240.626        963                                     
## ---------------------------------------------------------------------
## 
##                                    Parameter Estimates                                    
## -----------------------------------------------------------------------------------------
##       model      Beta    Std. Error    Std. Beta       t        Sig      lower     upper 
## -----------------------------------------------------------------------------------------
## (Intercept)     1.356         0.049                  27.552    0.000     1.259     1.452 
##     x9.baru    -0.361         0.027       -0.342    -13.534    0.000    -0.414    -0.309 
##    x12.baru    -0.163         0.013       -0.323    -12.956    0.000    -0.188    -0.138 
##    x13.baru    -0.256         0.021       -0.307    -12.144    0.000    -0.298    -0.215 
## -----------------------------------------------------------------------------------------
## 
## 
## 
## Stepwise Selection: Step 4 
## 
## - x8.baru added 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.695       RMSE                0.360 
## R-Squared               0.483       Coef. Var          69.332 
## Adj. R-Squared          0.480       MSE                 0.130 
## Pred R-Squared          0.477       MAE                 0.286 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                 ANOVA                                 
## ---------------------------------------------------------------------
##                Sum of                                                
##               Squares         DF    Mean Square       F         Sig. 
## ---------------------------------------------------------------------
## Regression    116.115          4         29.029    223.585    0.0000 
## Residual      124.510        959          0.130                      
## Total         240.626        963                                     
## ---------------------------------------------------------------------
## 
##                                    Parameter Estimates                                    
## -----------------------------------------------------------------------------------------
##       model      Beta    Std. Error    Std. Beta       t        Sig      lower     upper 
## -----------------------------------------------------------------------------------------
## (Intercept)     0.431         0.102                   4.242    0.000     0.231     0.630 
##     x9.baru    -0.262         0.027       -0.248     -9.639    0.000    -0.315    -0.208 
##    x12.baru    -0.142         0.012       -0.281    -11.681    0.000    -0.165    -0.118 
##    x13.baru    -0.253         0.020       -0.303    -12.605    0.000    -0.292    -0.213 
##     x8.baru     0.006         0.001        0.263     10.270    0.000     0.005     0.007 
## -----------------------------------------------------------------------------------------
## 
## 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.695       RMSE                0.360 
## R-Squared               0.483       Coef. Var          69.332 
## Adj. R-Squared          0.480       MSE                 0.130 
## Pred R-Squared          0.477       MAE                 0.286 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                 ANOVA                                 
## ---------------------------------------------------------------------
##                Sum of                                                
##               Squares         DF    Mean Square       F         Sig. 
## ---------------------------------------------------------------------
## Regression    116.115          4         29.029    223.585    0.0000 
## Residual      124.510        959          0.130                      
## Total         240.626        963                                     
## ---------------------------------------------------------------------
## 
##                                    Parameter Estimates                                    
## -----------------------------------------------------------------------------------------
##       model      Beta    Std. Error    Std. Beta       t        Sig      lower     upper 
## -----------------------------------------------------------------------------------------
## (Intercept)     0.431         0.102                   4.242    0.000     0.231     0.630 
##     x9.baru    -0.262         0.027       -0.248     -9.639    0.000    -0.315    -0.208 
##    x12.baru    -0.142         0.012       -0.281    -11.681    0.000    -0.165    -0.118 
##    x13.baru    -0.253         0.020       -0.303    -12.605    0.000    -0.292    -0.213 
##     x8.baru     0.006         0.001        0.263     10.270    0.000     0.005     0.007 
## -----------------------------------------------------------------------------------------
## 
## 
## 
## Stepwise Selection: Step 5 
## 
## - x3.baru added 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.717       RMSE                0.349 
## R-Squared               0.514       Coef. Var          67.208 
## Adj. R-Squared          0.512       MSE                 0.122 
## Pred R-Squared          0.508       MAE                 0.275 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                 ANOVA                                 
## ---------------------------------------------------------------------
##                Sum of                                                
##               Squares         DF    Mean Square       F         Sig. 
## ---------------------------------------------------------------------
## Regression    123.748          5         24.750    202.863    0.0000 
## Residual      116.878        958          0.122                      
## Total         240.626        963                                     
## ---------------------------------------------------------------------
## 
##                                    Parameter Estimates                                    
## -----------------------------------------------------------------------------------------
##       model      Beta    Std. Error    Std. Beta       t        Sig      lower     upper 
## -----------------------------------------------------------------------------------------
## (Intercept)     0.381         0.099                   3.863    0.000     0.187     0.574 
##     x9.baru    -0.199         0.027       -0.189     -7.251    0.000    -0.253    -0.145 
##    x12.baru    -0.133         0.012       -0.263    -11.262    0.000    -0.156    -0.110 
##    x13.baru    -0.236         0.020       -0.283    -12.076    0.000    -0.274    -0.198 
##     x8.baru     0.005         0.001        0.230      9.138    0.000     0.004     0.006 
##     x3.baru     0.097         0.012        0.200      7.910    0.000     0.073     0.122 
## -----------------------------------------------------------------------------------------
## 
## 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.717       RMSE                0.349 
## R-Squared               0.514       Coef. Var          67.208 
## Adj. R-Squared          0.512       MSE                 0.122 
## Pred R-Squared          0.508       MAE                 0.275 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                 ANOVA                                 
## ---------------------------------------------------------------------
##                Sum of                                                
##               Squares         DF    Mean Square       F         Sig. 
## ---------------------------------------------------------------------
## Regression    123.748          5         24.750    202.863    0.0000 
## Residual      116.878        958          0.122                      
## Total         240.626        963                                     
## ---------------------------------------------------------------------
## 
##                                    Parameter Estimates                                    
## -----------------------------------------------------------------------------------------
##       model      Beta    Std. Error    Std. Beta       t        Sig      lower     upper 
## -----------------------------------------------------------------------------------------
## (Intercept)     0.381         0.099                   3.863    0.000     0.187     0.574 
##     x9.baru    -0.199         0.027       -0.189     -7.251    0.000    -0.253    -0.145 
##    x12.baru    -0.133         0.012       -0.263    -11.262    0.000    -0.156    -0.110 
##    x13.baru    -0.236         0.020       -0.283    -12.076    0.000    -0.274    -0.198 
##     x8.baru     0.005         0.001        0.230      9.138    0.000     0.004     0.006 
##     x3.baru     0.097         0.012        0.200      7.910    0.000     0.073     0.122 
## -----------------------------------------------------------------------------------------
## 
## 
## 
## Stepwise Selection: Step 6 
## 
## - x2.baru added 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.739       RMSE                0.338 
## R-Squared               0.546       Coef. Var          64.988 
## Adj. R-Squared          0.543       MSE                 0.114 
## Pred R-Squared          0.539       MAE                 0.268 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                 ANOVA                                 
## ---------------------------------------------------------------------
##                Sum of                                                
##               Squares         DF    Mean Square       F         Sig. 
## ---------------------------------------------------------------------
## Regression    131.457          6         21.910    192.066    0.0000 
## Residual      109.168        957          0.114                      
## Total         240.626        963                                     
## ---------------------------------------------------------------------
## 
##                                    Parameter Estimates                                    
## -----------------------------------------------------------------------------------------
##       model      Beta    Std. Error    Std. Beta       t        Sig      lower     upper 
## -----------------------------------------------------------------------------------------
## (Intercept)     0.422         0.095                   4.416    0.000     0.234     0.609 
##     x9.baru    -0.176         0.027       -0.167     -6.604    0.000    -0.229    -0.124 
##    x12.baru    -0.127         0.011       -0.251    -11.088    0.000    -0.149    -0.104 
##    x13.baru    -0.204         0.019       -0.244    -10.552    0.000    -0.242    -0.166 
##     x8.baru     0.005         0.001        0.233      9.584    0.000     0.004     0.006 
##     x3.baru     0.101         0.012        0.206      8.453    0.000     0.077     0.124 
##     x2.baru    -0.203         0.025       -0.186     -8.221    0.000    -0.251    -0.154 
## -----------------------------------------------------------------------------------------
## 
## 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.739       RMSE                0.338 
## R-Squared               0.546       Coef. Var          64.988 
## Adj. R-Squared          0.543       MSE                 0.114 
## Pred R-Squared          0.539       MAE                 0.268 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                 ANOVA                                 
## ---------------------------------------------------------------------
##                Sum of                                                
##               Squares         DF    Mean Square       F         Sig. 
## ---------------------------------------------------------------------
## Regression    131.457          6         21.910    192.066    0.0000 
## Residual      109.168        957          0.114                      
## Total         240.626        963                                     
## ---------------------------------------------------------------------
## 
##                                    Parameter Estimates                                    
## -----------------------------------------------------------------------------------------
##       model      Beta    Std. Error    Std. Beta       t        Sig      lower     upper 
## -----------------------------------------------------------------------------------------
## (Intercept)     0.422         0.095                   4.416    0.000     0.234     0.609 
##     x9.baru    -0.176         0.027       -0.167     -6.604    0.000    -0.229    -0.124 
##    x12.baru    -0.127         0.011       -0.251    -11.088    0.000    -0.149    -0.104 
##    x13.baru    -0.204         0.019       -0.244    -10.552    0.000    -0.242    -0.166 
##     x8.baru     0.005         0.001        0.233      9.584    0.000     0.004     0.006 
##     x3.baru     0.101         0.012        0.206      8.453    0.000     0.077     0.124 
##     x2.baru    -0.203         0.025       -0.186     -8.221    0.000    -0.251    -0.154 
## -----------------------------------------------------------------------------------------
## 
## 
## 
## Stepwise Selection: Step 7 
## 
## - x11.baru added 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.756       RMSE                0.328 
## R-Squared               0.572       Coef. Var          63.138 
## Adj. R-Squared          0.569       MSE                 0.108 
## Pred R-Squared          0.565       MAE                 0.261 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                 ANOVA                                 
## ---------------------------------------------------------------------
##                Sum of                                                
##               Squares         DF    Mean Square       F         Sig. 
## ---------------------------------------------------------------------
## Regression    137.692          7         19.670     182.69    0.0000 
## Residual      102.933        956          0.108                      
## Total         240.626        963                                     
## ---------------------------------------------------------------------
## 
##                                    Parameter Estimates                                    
## -----------------------------------------------------------------------------------------
##       model      Beta    Std. Error    Std. Beta       t        Sig      lower     upper 
## -----------------------------------------------------------------------------------------
## (Intercept)     0.430         0.093                   4.641    0.000     0.248     0.612 
##     x9.baru    -0.147         0.026       -0.140     -5.615    0.000    -0.199    -0.096 
##    x12.baru    -0.134         0.011       -0.266    -12.022    0.000    -0.156    -0.112 
##    x13.baru    -0.196         0.019       -0.235    -10.448    0.000    -0.233    -0.159 
##     x8.baru     0.003         0.001        0.158      6.172    0.000     0.002     0.005 
##     x3.baru     0.107         0.012        0.219      9.209    0.000     0.084     0.130 
##     x2.baru    -0.203         0.024       -0.186     -8.470    0.000    -0.250    -0.156 
##    x11.baru     0.151         0.020        0.182      7.610    0.000     0.112     0.189 
## -----------------------------------------------------------------------------------------
## 
## 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.756       RMSE                0.328 
## R-Squared               0.572       Coef. Var          63.138 
## Adj. R-Squared          0.569       MSE                 0.108 
## Pred R-Squared          0.565       MAE                 0.261 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                 ANOVA                                 
## ---------------------------------------------------------------------
##                Sum of                                                
##               Squares         DF    Mean Square       F         Sig. 
## ---------------------------------------------------------------------
## Regression    137.692          7         19.670     182.69    0.0000 
## Residual      102.933        956          0.108                      
## Total         240.626        963                                     
## ---------------------------------------------------------------------
## 
##                                    Parameter Estimates                                    
## -----------------------------------------------------------------------------------------
##       model      Beta    Std. Error    Std. Beta       t        Sig      lower     upper 
## -----------------------------------------------------------------------------------------
## (Intercept)     0.430         0.093                   4.641    0.000     0.248     0.612 
##     x9.baru    -0.147         0.026       -0.140     -5.615    0.000    -0.199    -0.096 
##    x12.baru    -0.134         0.011       -0.266    -12.022    0.000    -0.156    -0.112 
##    x13.baru    -0.196         0.019       -0.235    -10.448    0.000    -0.233    -0.159 
##     x8.baru     0.003         0.001        0.158      6.172    0.000     0.002     0.005 
##     x3.baru     0.107         0.012        0.219      9.209    0.000     0.084     0.130 
##     x2.baru    -0.203         0.024       -0.186     -8.470    0.000    -0.250    -0.156 
##    x11.baru     0.151         0.020        0.182      7.610    0.000     0.112     0.189 
## -----------------------------------------------------------------------------------------
## 
## 
## 
## Stepwise Selection: Step 8 
## 
## - x10.baru added 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.762       RMSE                0.325 
## R-Squared               0.580       Coef. Var          62.588 
## Adj. R-Squared          0.577       MSE                 0.106 
## Pred R-Squared          0.572       MAE                 0.261 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                 ANOVA                                 
## ---------------------------------------------------------------------
##                Sum of                                                
##               Squares         DF    Mean Square       F         Sig. 
## ---------------------------------------------------------------------
## Regression    139.584          8         17.448     164.91    0.0000 
## Residual      101.042        955          0.106                      
## Total         240.626        963                                     
## ---------------------------------------------------------------------
## 
##                                    Parameter Estimates                                    
## -----------------------------------------------------------------------------------------
##       model      Beta    Std. Error    Std. Beta       t        Sig      lower     upper 
## -----------------------------------------------------------------------------------------
## (Intercept)     0.536         0.095                   5.628    0.000     0.349     0.723 
##     x9.baru    -0.133         0.026       -0.126     -5.054    0.000    -0.184    -0.081 
##    x12.baru    -0.127         0.011       -0.252    -11.384    0.000    -0.149    -0.105 
##    x13.baru    -0.184         0.019       -0.221     -9.793    0.000    -0.221    -0.147 
##     x8.baru     0.003         0.001        0.147      5.769    0.000     0.002     0.004 
##     x3.baru     0.108         0.012        0.222      9.403    0.000     0.086     0.131 
##     x2.baru    -0.197         0.024       -0.180     -8.269    0.000    -0.243    -0.150 
##    x11.baru     0.108         0.022        0.130      4.871    0.000     0.064     0.151 
##    x10.baru    -0.051         0.012       -0.113     -4.228    0.000    -0.074    -0.027 
## -----------------------------------------------------------------------------------------
## 
## 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.762       RMSE                0.325 
## R-Squared               0.580       Coef. Var          62.588 
## Adj. R-Squared          0.577       MSE                 0.106 
## Pred R-Squared          0.572       MAE                 0.261 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                 ANOVA                                 
## ---------------------------------------------------------------------
##                Sum of                                                
##               Squares         DF    Mean Square       F         Sig. 
## ---------------------------------------------------------------------
## Regression    139.584          8         17.448     164.91    0.0000 
## Residual      101.042        955          0.106                      
## Total         240.626        963                                     
## ---------------------------------------------------------------------
## 
##                                    Parameter Estimates                                    
## -----------------------------------------------------------------------------------------
##       model      Beta    Std. Error    Std. Beta       t        Sig      lower     upper 
## -----------------------------------------------------------------------------------------
## (Intercept)     0.536         0.095                   5.628    0.000     0.349     0.723 
##     x9.baru    -0.133         0.026       -0.126     -5.054    0.000    -0.184    -0.081 
##    x12.baru    -0.127         0.011       -0.252    -11.384    0.000    -0.149    -0.105 
##    x13.baru    -0.184         0.019       -0.221     -9.793    0.000    -0.221    -0.147 
##     x8.baru     0.003         0.001        0.147      5.769    0.000     0.002     0.004 
##     x3.baru     0.108         0.012        0.222      9.403    0.000     0.086     0.131 
##     x2.baru    -0.197         0.024       -0.180     -8.269    0.000    -0.243    -0.150 
##    x11.baru     0.108         0.022        0.130      4.871    0.000     0.064     0.151 
##    x10.baru    -0.051         0.012       -0.113     -4.228    0.000    -0.074    -0.027 
## -----------------------------------------------------------------------------------------
## 
## 
## 
## Stepwise Selection: Step 9 
## 
## - x5.baru added 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.764       RMSE                0.324 
## R-Squared               0.583       Coef. Var          62.385 
## Adj. R-Squared          0.579       MSE                 0.105 
## Pred R-Squared          0.574       MAE                 0.262 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                 ANOVA                                 
## ---------------------------------------------------------------------
##                Sum of                                                
##               Squares         DF    Mean Square       F         Sig. 
## ---------------------------------------------------------------------
## Regression    140.343          9         15.594    148.345    0.0000 
## Residual      100.282        954          0.105                      
## Total         240.626        963                                     
## ---------------------------------------------------------------------
## 
##                                    Parameter Estimates                                    
## -----------------------------------------------------------------------------------------
##       model      Beta    Std. Error    Std. Beta       t        Sig      lower     upper 
## -----------------------------------------------------------------------------------------
## (Intercept)     0.673         0.108                   6.246    0.000     0.462     0.884 
##     x9.baru    -0.129         0.026       -0.122     -4.933    0.000    -0.180    -0.078 
##    x12.baru    -0.124         0.011       -0.246    -11.070    0.000    -0.146    -0.102 
##    x13.baru    -0.179         0.019       -0.214     -9.492    0.000    -0.216    -0.142 
##     x8.baru     0.003         0.001        0.148      5.814    0.000     0.002     0.004 
##     x3.baru     0.107         0.011        0.219      9.305    0.000     0.084     0.129 
##     x2.baru    -0.211         0.024       -0.193     -8.685    0.000    -0.259    -0.163 
##    x11.baru     0.110         0.022        0.133      4.985    0.000     0.067     0.153 
##    x10.baru    -0.050         0.012       -0.111     -4.158    0.000    -0.073    -0.026 
##     x5.baru    -0.001         0.000       -0.058     -2.688    0.007    -0.001     0.000 
## -----------------------------------------------------------------------------------------
## 
## 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.764       RMSE                0.324 
## R-Squared               0.583       Coef. Var          62.385 
## Adj. R-Squared          0.579       MSE                 0.105 
## Pred R-Squared          0.574       MAE                 0.262 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                 ANOVA                                 
## ---------------------------------------------------------------------
##                Sum of                                                
##               Squares         DF    Mean Square       F         Sig. 
## ---------------------------------------------------------------------
## Regression    140.343          9         15.594    148.345    0.0000 
## Residual      100.282        954          0.105                      
## Total         240.626        963                                     
## ---------------------------------------------------------------------
## 
##                                    Parameter Estimates                                    
## -----------------------------------------------------------------------------------------
##       model      Beta    Std. Error    Std. Beta       t        Sig      lower     upper 
## -----------------------------------------------------------------------------------------
## (Intercept)     0.673         0.108                   6.246    0.000     0.462     0.884 
##     x9.baru    -0.129         0.026       -0.122     -4.933    0.000    -0.180    -0.078 
##    x12.baru    -0.124         0.011       -0.246    -11.070    0.000    -0.146    -0.102 
##    x13.baru    -0.179         0.019       -0.214     -9.492    0.000    -0.216    -0.142 
##     x8.baru     0.003         0.001        0.148      5.814    0.000     0.002     0.004 
##     x3.baru     0.107         0.011        0.219      9.305    0.000     0.084     0.129 
##     x2.baru    -0.211         0.024       -0.193     -8.685    0.000    -0.259    -0.163 
##    x11.baru     0.110         0.022        0.133      4.985    0.000     0.067     0.153 
##    x10.baru    -0.050         0.012       -0.111     -4.158    0.000    -0.073    -0.026 
##     x5.baru    -0.001         0.000       -0.058     -2.688    0.007    -0.001     0.000 
## -----------------------------------------------------------------------------------------
## 
## 
## 
## Stepwise Selection: Step 10 
## 
## - x4.baru added 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.765       RMSE                0.324 
## R-Squared               0.585       Coef. Var          62.261 
## Adj. R-Squared          0.581       MSE                 0.105 
## Pred R-Squared          0.575       MAE                 0.262 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                 ANOVA                                 
## ---------------------------------------------------------------------
##                Sum of                                                
##               Squares         DF    Mean Square       F         Sig. 
## ---------------------------------------------------------------------
## Regression    140.844         10         14.084    134.518    0.0000 
## Residual       99.782        953          0.105                      
## Total         240.626        963                                     
## ---------------------------------------------------------------------
## 
##                                    Parameter Estimates                                    
## -----------------------------------------------------------------------------------------
##       model      Beta    Std. Error    Std. Beta       t        Sig      lower     upper 
## -----------------------------------------------------------------------------------------
## (Intercept)     0.823         0.127                   6.454    0.000     0.573     1.073 
##     x9.baru    -0.128         0.026       -0.122     -4.909    0.000    -0.180    -0.077 
##    x12.baru    -0.121         0.011       -0.241    -10.803    0.000    -0.143    -0.099 
##    x13.baru    -0.177         0.019       -0.213     -9.418    0.000    -0.214    -0.140 
##     x8.baru     0.003         0.001        0.152      5.970    0.000     0.002     0.004 
##     x3.baru     0.109         0.012        0.224      9.497    0.000     0.087     0.132 
##     x2.baru    -0.214         0.024       -0.196     -8.800    0.000    -0.261    -0.166 
##    x11.baru     0.107         0.022        0.129      4.857    0.000     0.064     0.150 
##    x10.baru    -0.047         0.012       -0.106     -3.953    0.000    -0.071    -0.024 
##     x5.baru    -0.001         0.000       -0.052     -2.379    0.018    -0.001     0.000 
##     x4.baru    -0.001         0.001       -0.047     -2.186    0.029    -0.003     0.000 
## -----------------------------------------------------------------------------------------
## 
## 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.765       RMSE                0.324 
## R-Squared               0.585       Coef. Var          62.261 
## Adj. R-Squared          0.581       MSE                 0.105 
## Pred R-Squared          0.575       MAE                 0.262 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                 ANOVA                                 
## ---------------------------------------------------------------------
##                Sum of                                                
##               Squares         DF    Mean Square       F         Sig. 
## ---------------------------------------------------------------------
## Regression    140.844         10         14.084    134.518    0.0000 
## Residual       99.782        953          0.105                      
## Total         240.626        963                                     
## ---------------------------------------------------------------------
## 
##                                    Parameter Estimates                                    
## -----------------------------------------------------------------------------------------
##       model      Beta    Std. Error    Std. Beta       t        Sig      lower     upper 
## -----------------------------------------------------------------------------------------
## (Intercept)     0.823         0.127                   6.454    0.000     0.573     1.073 
##     x9.baru    -0.128         0.026       -0.122     -4.909    0.000    -0.180    -0.077 
##    x12.baru    -0.121         0.011       -0.241    -10.803    0.000    -0.143    -0.099 
##    x13.baru    -0.177         0.019       -0.213     -9.418    0.000    -0.214    -0.140 
##     x8.baru     0.003         0.001        0.152      5.970    0.000     0.002     0.004 
##     x3.baru     0.109         0.012        0.224      9.497    0.000     0.087     0.132 
##     x2.baru    -0.214         0.024       -0.196     -8.800    0.000    -0.261    -0.166 
##    x11.baru     0.107         0.022        0.129      4.857    0.000     0.064     0.150 
##    x10.baru    -0.047         0.012       -0.106     -3.953    0.000    -0.071    -0.024 
##     x5.baru    -0.001         0.000       -0.052     -2.379    0.018    -0.001     0.000 
##     x4.baru    -0.001         0.001       -0.047     -2.186    0.029    -0.003     0.000 
## -----------------------------------------------------------------------------------------
## 
## 
## 
## No more variables to be added/removed.
## 
## 
## Final Model Output 
## ------------------
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.765       RMSE                0.324 
## R-Squared               0.585       Coef. Var          62.261 
## Adj. R-Squared          0.581       MSE                 0.105 
## Pred R-Squared          0.575       MAE                 0.262 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                 ANOVA                                 
## ---------------------------------------------------------------------
##                Sum of                                                
##               Squares         DF    Mean Square       F         Sig. 
## ---------------------------------------------------------------------
## Regression    140.844         10         14.084    134.518    0.0000 
## Residual       99.782        953          0.105                      
## Total         240.626        963                                     
## ---------------------------------------------------------------------
## 
##                                    Parameter Estimates                                    
## -----------------------------------------------------------------------------------------
##       model      Beta    Std. Error    Std. Beta       t        Sig      lower     upper 
## -----------------------------------------------------------------------------------------
## (Intercept)     0.823         0.127                   6.454    0.000     0.573     1.073 
##     x9.baru    -0.128         0.026       -0.122     -4.909    0.000    -0.180    -0.077 
##    x12.baru    -0.121         0.011       -0.241    -10.803    0.000    -0.143    -0.099 
##    x13.baru    -0.177         0.019       -0.213     -9.418    0.000    -0.214    -0.140 
##     x8.baru     0.003         0.001        0.152      5.970    0.000     0.002     0.004 
##     x3.baru     0.109         0.012        0.224      9.497    0.000     0.087     0.132 
##     x2.baru    -0.214         0.024       -0.196     -8.800    0.000    -0.261    -0.166 
##    x11.baru     0.107         0.022        0.129      4.857    0.000     0.064     0.150 
##    x10.baru    -0.047         0.012       -0.106     -3.953    0.000    -0.071    -0.024 
##     x5.baru    -0.001         0.000       -0.052     -2.379    0.018    -0.001     0.000 
##     x4.baru    -0.001         0.001       -0.047     -2.186    0.029    -0.003     0.000 
## -----------------------------------------------------------------------------------------
## 
##                               Stepwise Selection Summary                                
## ---------------------------------------------------------------------------------------
##                      Added/                   Adj.                                         
## Step    Variable    Removed     R-Square    R-Square      C(p)         AIC        RMSE     
## ---------------------------------------------------------------------------------------
##    1    x9.baru     addition       0.212       0.211    850.4020    1174.3640    0.4440    
##    2    x12.baru    addition       0.337       0.336    563.9270    1009.0404    0.4073    
##    3    x13.baru    addition       0.426       0.424    363.2510     873.2726    0.3794    
##    4    x8.baru     addition       0.483       0.480    234.5410     774.6911    0.3603    
##    5    x3.baru     addition       0.514       0.512    163.6830     715.7084    0.3493    
##    6    x2.baru     addition       0.546       0.543     92.0890     651.9257    0.3377    
##    7    x11.baru    addition       0.572       0.569     34.5730     597.2344    0.3281    
##    8    x10.baru    addition       0.580       0.577     18.5170     581.3557    0.3253    
##    9    x5.baru     addition       0.583       0.579     13.2670     576.0818    0.3242    
##   10    x4.baru     addition       0.585       0.581     10.4890     573.2579    0.3236    
## ---------------------------------------------------------------------------------------

Hasil penyeleksian peubah pada model digambarkan oleh best subset dan stepwise bahwa mengeluarkan 3 peubah yaitu x1, x2, dan x7. Selanjutnya akan dibuat model tanpa peubah yang dikeluarkan tersebut.

Model Stepwise

model.stepwise <- lm(y.baru ~ x2.baru+x3.baru+x4.baru+x5.baru+x8.baru+x9.baru+x10.baru+x11.baru+x12.baru+x13.baru)
model.stepwise
## 
## Call:
## lm(formula = y.baru ~ x2.baru + x3.baru + x4.baru + x5.baru + 
##     x8.baru + x9.baru + x10.baru + x11.baru + x12.baru + x13.baru)
## 
## Coefficients:
## (Intercept)      x2.baru      x3.baru      x4.baru      x5.baru      x8.baru  
##    0.822657    -0.213773     0.109360    -0.001403    -0.000536     0.003353  
##     x9.baru     x10.baru     x11.baru     x12.baru     x13.baru  
##   -0.128254    -0.047259     0.106986    -0.121362    -0.177478

Diperoleh model hasil seleksi stepwise:

\[y = 0.822657 - 0.213773x_2 + 0.109360x_3 - 0.001403x_4 - 0.000536x_5 + 0.003353x_8 - 0.128254x_9 - 0.047259x_{10} + 0.106986x_{11} - 0.121362x_{12} - 0.177478x_{13} \]

summary(model.stepwise)
## 
## Call:
## lm(formula = y.baru ~ x2.baru + x3.baru + x4.baru + x5.baru + 
##     x8.baru + x9.baru + x10.baru + x11.baru + x12.baru + x13.baru)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.91440 -0.20136  0.05301  0.24880  0.70236 
## 
## Coefficients:
##               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  0.8226570  0.1274632   6.454 1.73e-10 ***
## x2.baru     -0.2137729  0.0242928  -8.800  < 2e-16 ***
## x3.baru      0.1093604  0.0115147   9.497  < 2e-16 ***
## x4.baru     -0.0014034  0.0006419  -2.186   0.0290 *  
## x5.baru     -0.0005360  0.0002253  -2.379   0.0176 *  
## x8.baru      0.0033526  0.0005616   5.970 3.35e-09 ***
## x9.baru     -0.1282544  0.0261242  -4.909 1.07e-06 ***
## x10.baru    -0.0472593  0.0119561  -3.953 8.30e-05 ***
## x11.baru     0.1069860  0.0220273   4.857 1.39e-06 ***
## x12.baru    -0.1213620  0.0112337 -10.803  < 2e-16 ***
## x13.baru    -0.1774780  0.0188442  -9.418  < 2e-16 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.3236 on 953 degrees of freedom
## Multiple R-squared:  0.5853, Adjusted R-squared:  0.581 
## F-statistic: 134.5 on 10 and 953 DF,  p-value: < 2.2e-16

Diperoleh nilai p-value < 2.2e-16 < 0.05 dengan nilai R-squared 58.1%. Semua peubah penjelas pada model ini berpengaruh signifikan terhadap peubah respon.

Uji Asumsi

Normalitas

H0 : Sisaan menyebar normal

H1 : Sisaan tidak menyebar normal

uji.normal<-function(x, object.name="x", graph=TRUE, graph.transformed=TRUE){
  lapply(c("fitdistrplus", "kSamples", "rcompanion"), library, character.only=T) 
  if(any(x<0))x<-x-min(x)+1
  mean <- fitdist(x, "norm")$estimate[1]; sd <- fitdist(x, "norm")$estimate[2]
  uji<-ks.test(x, "pnorm", mean=mean, sd=sd)
  uji1<- ad.test(x, rnorm(length(x), mean=mean, sd=sd))
  pvalue<-uji$p.value
  PVALUE1<-uji1$ad[1,3]
  PVALUE2<-uji1$ad[2,3]
  t<-transformTukey(x,quiet = TRUE,plotit = FALSE)
  pt<-ks.test(t, "pnorm", mean=fitdist(t,"norm")$estimate[1], 
              sd=fitdist(t,"norm")$estimate[2])$p.value
  lambda<-transformTukey(x,returnLambda =TRUE,quiet=TRUE,plotit = FALSE)
  if(graph==TRUE){
    if(graph.transformed==FALSE){
      par(mfrow=c(1,2))
      hist(x, freq=F, col="steelblue", border="white", 
           main=paste("Histogram of ",object.name),xlab=object.name)
      lines(density(x),lwd=2, col="coral")
      qqnorm(x,col="coral");qqline(x,col="steelblue",lwd=2)
    }
    else{
      par(mfrow=c(2,2))
      hist(x, freq=F, col="steelblue", border="white", 
           main=paste("Histogram of ",object.name),xlab=object.name)
      lines(density(x),lwd=2, col="coral")
      hist(t, main=paste("Histogram of ",object.name,"transformed"), 
           xlab=paste(object.name,"transformed"), freq=F, 
           col="steelblue",border = "white")
      lines(density(t),lwd=2, col="coral")
      qqnorm(x,col="coral");qqline(x,col="steelblue",lwd=2)
      qqnorm(t, col="coral");qqline(t,col="steelblue", lwd=2)
    }
  }
  z<-ifelse((PVALUE1>=0.05 & PVALUE2<0.05 ||PVALUE1<0.05 & PVALUE2>=0.05), 
            
            ifelse(pvalue>=0.05, 
                   return(`Hasil Uji Kolmogorov Smirnov`=data.frame(`P-Value`=pvalue,
                            Keputusan="Terima H0, data menyebar normal")), 
                   return(list(`Hasil Uji Kolmogorov Smirnov`=data.frame(`P-Value`=pvalue,
                                 Keputusan="Tolak H0, data tidak menyebar normal"),
                                 `lambda transformasi`=lambda,
                                 `Data Hasil Transformasi Tukey`= t,
                                `Setelah transformasi~Uji Kolmogorov-Smirnov`=data.frame(`P-Value`=pt, 
                                  `Keputusan`=ifelse(pt>=0.05, 
                                  "Terima H0, data menyebar normal", 
                                  "Tolak H0, data tidak menyebar normal"))))),
            
            ifelse(((pvalue >= 0.05)&(PVALUE1 >= 0.05||PVALUE2>= 0.05)), 
                   return(list(`Hasil Uji Kolmogorov Smirnov`=data.frame(`P-Value`=pvalue,
                                 Keputusan="Terima H0, data menyebar normal"), 
                                 `Hasil Uji Anderson`=
                                 data.frame(`P-Value`=
                                rbind(`Versi 1`=PVALUE1, `Versi 2`=PVALUE2),
                                Keputusan=rep("Terima H0, data menyebar normal", 2)))), 
                   
                   ifelse((pvalue >= 0.05&(PVALUE1 < 0.05||PVALUE2 < 0.05)),
                          return(list(`Hasil Uji Kolmogorov Smirnov`= data.frame(`P-Value`=pvalue,
                                        Keputusan="Terima H0, data menyebar normal"), 
                                      `Hasil Uji Anderson`=data.frame(`P-Value`=
                                        rbind(`Versi 1`=PVALUE1,`Versi 2`=PVALUE2), 
                                        Keputusan= rep("Tolak H0, data tidak menyebar normal",2)), 
                                        `lambda transformasi`=lambda,
                                        `Data Hasil Transformasi Tukey`= t,
                                        `Setelah transformasi~Uji Kolmogorov-Smirnov`=
                                        data.frame(`P-Value`=pt, 
                                        `Keputusan`=ifelse(pt>=0.05, 
                                            "Terima H0, data menyebar normal",
                                            "Tolak H0, data tidak menyebar normal")))),
                          
                          ifelse(pvalue < 0.05&(PVALUE1 >= 0.05||PVALUE2 >= 0.05),
                                 return(list(`Hasil Uji Kolmogorov Smirnov`=data.frame(`P-Value`=pvalue,
                                  Keputusan="Tolak H0, data tidak menyebar normal"), 
                                  `Hasil Uji Anderson`=data.frame(`P-Value`= rbind(`Versi 1`=PVALUE1,`Versi 2`=PVALUE2), 
                                    Keputusan=rep("Terima H0, data menyebar normal",2)),
                                  `lambda transformasi`=lambda,
                                  `Data Hasil Transformasi Tukey`= t,
                                  `Setelah transformasi~Uji Kolmogorov-Smirnov`=data.frame(`P-Value`=pt, 
                                  `Keputusan`=ifelse(pt>=0.05, 
                                  "Terima H0, data menyebar normal", 
                                  "Tolak H0, data tidak menyebar normal")))),
                                 
                                 return(list(`Hasil Uji Kolmogorov Smirnov`=data.frame(`P-Value`=pvalue,
                                               Keputusan="Tolak H0, data tidak menyebar normal"),
                                               `Hasil Uji Anderson`=data.frame(`P-Value`=rbind(`Versi 1`=PVALUE1,
                                                    `Versi 2`=PVALUE2), 
                                                                                                                                                                          Keputusan=rep("Tolak H0, data tidak menyebar normal",2)), 
                                             `lambda transformasi`=lambda,
                                             `Data Hasil Transformasi Tukey`= t,
                                             `Setelah transformasi~Uji Kolmogorov-Smirnov`=data.frame(`P-Value`=pt,
                                              `Keputusan`=ifelse(pt>=0.05, 
                                              "Terima H0, data menyebar normal", 
                                              "Tolak H0, data tidak menyebar normal"))))))))
  return(z)
}

uji.normal1<-function(x, object.name="x", graph=TRUE, graph.transformed=TRUE){
  lapply(c("fitdistrplus", "kSamples", "rcompanion"), library, character.only=T) 
  if(any(x<0))x<-x-min(x)+1
  mean <- mean(x); sd <- sd(x)
  uji<-ks.test(x, "pnorm", mean=mean, sd=sd)
  uji1<- ad.test(x, rnorm(length(x), mean=mean, sd=sd))
  pvalue<-uji$p.value
  PVALUE1<-uji1$ad[1,3]
  PVALUE2<-uji1$ad[2,3]
  t<-transformTukey(x,quiet = TRUE,plotit = FALSE)
  pt<-ks.test(t, "pnorm", mean=mean(t), 
              sd=sd(t))$p.value
  lambda<-transformTukey(x,returnLambda =TRUE,quiet=TRUE,plotit = FALSE)
  if(graph==TRUE){
    if(graph.transformed==FALSE){
      par(mfrow=c(1,2))
      hist(x, freq=F, col="steelblue", border="white", 
           main=paste("Histogram of ",object.name),xlab=object.name)
      lines(density(x),lwd=2, col="coral")
      qqnorm(x,col="coral");qqline(x,col="steelblue",lwd=2)
    }
    else{
      par(mfrow=c(2,2))
      hist(x, freq=F, col="steelblue", border="white", 
           main=paste("Histogram of ",object.name),xlab=object.name)
      lines(density(x),lwd=2, col="coral")
      hist(t, main=paste("Histogram of ",object.name,"transformed"), 
           xlab=paste(object.name,"transformed"), freq=F, 
           col="steelblue",border = "white")
      lines(density(t),lwd=2, col="coral")
      qqnorm(x,col="coral");qqline(x,col="steelblue",lwd=2)
      qqnorm(t, col="coral");qqline(t,col="steelblue", lwd=2)
    }
  }
  z<-ifelse((PVALUE1>=0.05 & PVALUE2<0.05 ||PVALUE1<0.05 & PVALUE2>=0.05), 
            
            ifelse(pvalue>=0.05, 
                   return(`Hasil Uji Kolmogorov Smirnov`=data.frame(`P-Value`=pvalue,
                                                                    Keputusan="Terima H0, data menyebar normal")), 
                   return(list(`Hasil Uji Kolmogorov Smirnov`=data.frame(`P-Value`=pvalue,
                                                                         Keputusan="Tolak H0, data tidak menyebar normal"),
                               `lambda transformasi`=lambda,
                               `Data Hasil Transformasi Tukey`= t,
                               `Setelah transformasi~Uji Kolmogorov-Smirnov`=data.frame(`P-Value`=pt, 
                                                                                        `Keputusan`=ifelse(pt>=0.05, 
                                                                                                           "Terima H0, data menyebar normal", 
                                                                                                           "Tolak H0, data tidak menyebar normal"))))),
            
            ifelse(((pvalue >= 0.05)&(PVALUE1 >= 0.05||PVALUE2>= 0.05)), 
                   return(list(`Hasil Uji Kolmogorov Smirnov`=data.frame(`P-Value`=pvalue,
                                                                         Keputusan="Terima H0, data menyebar normal"), 
                               `Hasil Uji Anderson`=
                                 data.frame(`P-Value`=
                                              rbind(`Versi 1`=PVALUE1, `Versi 2`=PVALUE2),
                                            Keputusan=rep("Terima H0, data menyebar normal", 2)))), 
                   
                   ifelse((pvalue >= 0.05&(PVALUE1 < 0.05||PVALUE2 < 0.05)),
                          return(list(`Hasil Uji Kolmogorov Smirnov`= data.frame(`P-Value`=pvalue,
                                                                                 Keputusan="Terima H0, data menyebar normal"), 
                                      `Hasil Uji Anderson`=data.frame(`P-Value`=
                                                                        rbind(`Versi 1`=PVALUE1,`Versi 2`=PVALUE2), 
                                                                      Keputusan= rep("Tolak H0, data tidak menyebar normal",2)), 
                                      `lambda transformasi`=lambda,
                                      `Data Hasil Transformasi Tukey`= t,
                                      `Setelah transformasi~Uji Kolmogorov-Smirnov`=
                                        data.frame(`P-Value`=pt, 
                                                   `Keputusan`=ifelse(pt>=0.05, 
                                                                      "Terima H0, data menyebar normal",
                                                                      "Tolak H0, data tidak menyebar normal")))),
                          
                          ifelse(pvalue < 0.05&(PVALUE1 >= 0.05||PVALUE2 >= 0.05),
                                 return(list(`Hasil Uji Kolmogorov Smirnov`=data.frame(`P-Value`=pvalue,
                                                                                       Keputusan="Tolak H0, data tidak menyebar normal"), 
                                             `Hasil Uji Anderson`=data.frame(`P-Value`= rbind(`Versi 1`=PVALUE1,`Versi 2`=PVALUE2), 
                                                                             Keputusan=rep("Terima H0, data menyebar normal",2)),
                                             `lambda transformasi`=lambda,
                                             `Data Hasil Transformasi Tukey`= t,
                                             `Setelah transformasi~Uji Kolmogorov-Smirnov`=data.frame(`P-Value`=pt, 
                                                                                                      `Keputusan`=ifelse(pt>=0.05, 
                                                                                                                         "Terima H0, data menyebar normal", 
                                                                                                                         "Tolak H0, data tidak menyebar normal")))),
                                 
                                 return(list(`Hasil Uji Kolmogorov Smirnov`=data.frame(`P-Value`=pvalue,
                                                                                       Keputusan="Tolak H0, data tidak menyebar normal"),
                                             `Hasil Uji Anderson`=data.frame(`P-Value`=rbind(`Versi 1`=PVALUE1,
                                                                                             `Versi 2`=PVALUE2), 
                                                                             Keputusan=rep("Tolak H0, data tidak menyebar normal",2)), 
                                             `lambda transformasi`=lambda,
                                             `Data Hasil Transformasi Tukey`= t,
                                             `Setelah transformasi~Uji Kolmogorov-Smirnov`=data.frame(`P-Value`=pt,
                                                                                                      `Keputusan`=ifelse(pt>=0.05, 
                                                                                                                         "Terima H0, data menyebar normal", 
                                                                                                                         "Tolak H0, data tidak menyebar normal"))))))))
  return(z)
}

uji.normal(model.stepwise$residuals,"residuals",graph.transformed = F)
## Loading required package: MASS
## 
## Attaching package: 'MASS'
## The following object is masked from 'package:olsrr':
## 
##     cement
## Loading required package: survival
## Loading required package: SuppDists
## Warning in ks.test.default(x, "pnorm", mean = mean, sd = sd): ties should not
## be present for the Kolmogorov-Smirnov test
## Warning in ks.test.default(t, "pnorm", mean = fitdist(t, "norm")$estimate[1], :
## ties should not be present for the Kolmogorov-Smirnov test

## $`Hasil Uji Kolmogorov Smirnov`
##        P.Value                            Keputusan
## 1 7.003125e-05 Tolak H0, data tidak menyebar normal
## 
## $`Hasil Uji Anderson`
##          P.Value                            Keputusan
## Versi 1 0.011966 Tolak H0, data tidak menyebar normal
## Versi 2 0.012389 Tolak H0, data tidak menyebar normal
## 
## $`lambda transformasi`
## lambda 
##    2.1 
## 
## $`Data Hasil Transformasi Tukey`
##        1        2        3        4        5        6        7        8 
## 2.825218 3.842257 4.138848 2.416141 3.394072 5.496406 3.899300 2.280837 
##        9       10       11       12       13       14       15       16 
## 4.338133 5.404912 3.044838 3.399823 6.117575 3.399823 4.710552 4.449444 
##       17       18       19       20       21       22       23       24 
## 3.984218 4.216169 1.604555 5.654608 7.346630 3.285161 3.522610 2.583019 
##       25       26       27       28       29       30       31       32 
## 4.665274 1.513965 1.676180 2.408508 3.984218 3.868065 3.815985 4.141673 
##       33       34       35       36       37       38       39       40 
## 1.867507 5.774271 5.114122 2.188416 4.122570 5.988313 2.280837 4.251644 
##       41       42       43       44       45       46       47       48 
## 5.075186 4.856527 3.255376 4.686524 3.485172 3.320862 2.572362 6.401417 
##       49       50       51       52       53       54       55       56 
## 3.332805 5.095641 5.095641 5.344676 5.058096 1.949157 1.595488 4.072576 
##       57       58       59       60       61       62       63       64 
## 4.686524 3.633571 4.755249 4.072576 1.657985 5.628903 2.442453 3.152761 
##       65       66       67       68       69       70       71       72 
## 4.612186 3.468940 2.994765 2.760630 3.483327 4.451654 5.209612 4.277782 
##       73       74       75       76       77       78       79       80 
## 5.553832 5.553832 2.140751 2.190671 1.867507 6.401417 3.152761 4.531596 
##       81       82       83       84       85       86       87       88 
## 4.216169 1.925675 2.910850 4.140749 3.234114 4.163358 4.277782 2.408508 
##       89       90       91       92       93       94       95       96 
## 5.033715 5.686621 5.054150 5.245732 1.728469 4.684075 3.692119 5.409094 
##       97       98       99      100      101      102      103      104 
## 5.795788 4.451654 2.958708 3.264194 2.699381 3.367698 1.878040 3.069414 
##      105      106      107      108      109      110      111      112 
## 1.556224 3.483327 4.183637 1.536774 2.583019 3.216439 3.591637 4.072576 
##      113      114      115      116      117      118      119      120 
## 4.847755 5.795788 2.408508 4.810856 4.593344 4.238259 3.096781 6.267365 
##      121      122      123      124      125      126      127      128 
## 5.628903 6.620695 5.227656 3.096781 3.671784 4.856527 4.141673 5.795788 
##      129      130      131      132      133      134      135      136 
## 2.460203 4.251644 5.600864 4.451654 4.771164 4.761255 1.711550 2.083291 
##      137      138      139      140      141      142      143      144 
## 3.429028 5.430512 3.498291 3.608874 1.851350 5.418027 4.224940 2.037325 
##      145      146      147      148      149      150      151      152 
## 2.788617 5.988313 4.836321 5.795788 5.220552 5.988313 4.195467 3.177239 
##      153      154      155      156      157      158      159      160 
## 5.747597 3.177239 2.405696 2.994765 4.612186 2.886844 5.242137 5.475266 
##      161      162      163      164      165      166      167      168 
## 4.335114 5.681443 4.426142 5.653166 2.871335 4.166267 4.426142 4.253283 
##      169      170      171      172      173      174      175      176 
## 1.556224 3.774603 4.277782 5.354837 3.492446 4.304280 4.806439 4.811851 
##      177      178      179      180      181      182      183      184 
## 3.498291 2.994765 3.216439 2.780679 3.929925 5.588177 5.553214 4.905199 
##      185      186      187      188      189      190      191      192 
## 4.755249 2.319630 4.878890 3.902881 3.390674 4.163358 3.429028 5.418027 
##      193      194      195      196      197      198      199      200 
## 5.602642 4.686524 4.944902 1.536774 3.929925 6.401417 3.367698 3.633571 
##      201      202      203      204      205      206      207      208 
## 3.299167 5.475266 4.806439 4.831798 3.783557 4.195467 4.979854 4.338133 
##      209      210      211      212      213      214      215      216 
## 3.216439 5.354837 2.871335 5.684293 5.554685 2.190671 4.525950 4.331234 
##      217      218      219      220      221      222      223      224 
## 3.255376 2.788617 4.622727 4.082223 3.925161 4.345282 5.602642 2.190671 
##      225      226      227      228      229      230      231      232 
## 1.936919 3.485172 1.904785 5.135293 1.949157 6.401417 1.604555 5.229079 
##      233      234      235      236      237      238      239      240 
## 4.317218 2.037325 4.979854 3.947763 4.304280 3.264194 4.335114 4.149644 
##      241      242      243      244      245      246      247      248 
## 4.811851 3.330906 5.633173 4.199687 5.600864 2.005166 6.267365 4.068335 
##      249      250      251      252      253      254      255      256 
## 5.554685 4.812195 4.251644 2.460203 7.346630 5.245732 2.892079 2.424284 
##      257      258      259      260      261      262      263      264 
## 4.268858 6.024135 5.459415 3.947763 3.069414 5.550852 4.426142 6.764856 
##      265      266      267      268      269      270      271      272 
## 4.317218 3.899300 3.999631 4.196988 4.413725 3.869208 5.354837 2.424284 
##      273      274      275      276      277      278      279      280 
## 4.268858 4.841697 5.379491 3.388250 1.878040 6.620695 4.875619 6.241610 
##      281      282      283      284      285      286      287      288 
## 4.755249 3.633571 2.892079 3.329327 4.413725 4.809455 3.449885 6.243980 
##      289      290      291      292      293      294      295      296 
## 4.251644 4.810856 3.660555 5.071593 4.525950 4.531596 1.536774 4.907264 
##      297      298      299      300      301      302      303      304 
## 4.238259 3.483327 3.815985 5.693779 5.220552 4.944902 4.841697 3.285161 
##      305      306      307      308      309      310      311      312 
## 2.760630 2.574886 5.252781 3.795430 4.727722 3.096935 5.058096 4.907264 
##      313      314      315      316      317      318      319      320 
## 2.037325 2.814923 4.380324 2.574886 3.152761 2.425601 5.731995 4.003961 
##      321      322      323      324      325      326      327      328 
## 4.588102 3.329327 5.409094 6.280962 1.676180 3.336831 6.401417 4.068335 
##      329      330      331      332      333      334      335      336 
## 3.923460 5.407552 4.195467 3.096935 3.299167 3.234114 5.175330 2.261046 
##      337      338      339      340      341      342      343      344 
## 6.267365 3.390674 4.183637 6.368887 1.936919 5.656911 4.905199 2.574886 
##      345      346      347      348      349      350      351      352 
## 4.812195 3.692119 5.887695 5.887695 2.274866 2.309547 6.445090 4.711438 
##      353      354      355      356      357      358      359      360 
## 3.044838 4.149644 4.003961 1.772720 5.138263 5.550852 5.390706 7.514827 
##      361      362      363      364      365      366      367      368 
## 2.892079 2.958708 3.920133 2.424284 3.613683 3.329327 2.534709 4.711438 
##      369      370      371      372      373      374      375      376 
## 3.522610 3.177239 4.253283 4.698027 1.513965 1.771359 4.711438 4.836321 
##      377      378      379      380      381      382      383      384 
## 4.686524 2.728120 3.498291 5.550852 4.698027 3.332805 5.404912 5.276986 
##      385      386      387      388      389      390      391      392 
## 3.449885 3.468940 1.676180 4.216169 2.319630 5.656911 1.867507 3.999631 
##      393      394      395      396      397      398      399      400 
## 2.994765 2.814923 4.380324 1.657985 3.869208 6.280962 6.620695 4.163358 
##      401      402      403      404      405      406      407      408 
## 4.122570 5.054150 5.460654 5.242137 1.513965 4.727722 2.585569 3.939963 
##      409      410      411      412      413      414      415      416 
## 4.380367 5.175330 1.000000 1.949157 3.754003 3.902881 5.731995 3.707926 
##      417      418      419      420      421      422      423      424 
## 5.242137 1.925675 4.671534 4.046382 1.772720 1.904785 3.492446 4.761255 
##      425      426      427      428      429      430      431      432 
## 4.380367 4.046382 4.331234 5.887695 3.899300 3.608874 1.768468 4.209482 
##      433      434      435      436      437      438      439      440 
## 4.380097 3.255376 4.380097 3.754003 5.553214 1.000000 3.947763 5.681443 
##      441      442      443      444      445      446      447      448 
## 5.684293 3.492475 5.209612 2.958708 6.024135 6.401417 4.317218 3.264194 
##      449      450      451      452      453      454      455      456 
## 6.241610 4.905199 3.096781 4.841697 5.321972 5.054767 2.309547 5.409094 
##      457      458      459      460      461      462      463      464 
## 4.811851 2.188416 4.224940 5.154903 2.585569 4.209482 6.117575 4.413725 
##      465      466      467      468      469      470      471      472 
## 1.728469 3.367698 1.851350 3.783557 5.135293 6.241610 5.054150 4.380367 
##      473      474      475      476      477      478      479      480 
## 2.780679 4.149644 5.229079 7.021804 2.728120 1.595488 5.704308 5.138263 
##      481      482      483      484      485      486      487      488 
## 5.404912 4.199687 5.138263 4.196988 1.000000 4.525950 4.238259 3.869208 
##      489      490      491      492      493      494      495      496 
## 5.135293 3.591637 1.929616 3.069414 4.531596 3.332805 4.588102 3.999631 
##      497      498      499      500      501      502      503      504 
## 3.332805 2.416141 2.760630 3.937095 2.416141 2.274866 3.671784 4.163358 
##      505      506      507      508      509      510      511      512 
## 7.538828 5.553214 3.067221 3.923460 1.711550 4.356740 3.234114 4.684075 
##      513      514      515      516      517      518      519      520 
## 4.076899 4.809455 2.280837 5.602642 4.875619 4.050899 5.633173 6.280962 
##      521      522      523      524      525      526      527      528 
## 2.309547 4.380324 5.654608 3.608874 6.186807 3.492475 4.338133 3.044838 
##      529      530      531      532      533      534      535      536 
## 5.628903 2.319630 3.231919 2.760630 4.812195 2.871335 2.892079 5.321972 
##      537      538      539      540      541      542      543      544 
## 3.923460 3.522610 1.929616 2.886844 4.356740 4.243020 5.054767 3.939963 
##      545      546      547      548      549      550      551      552 
## 3.422010 4.810856 3.429028 1.929616 4.082223 5.681443 5.418027 4.380324 
##      553      554      555      556      557      558      559      560 
## 5.633173 3.920133 5.433663 4.050899 4.943371 3.591637 4.149644 5.220552 
##      561      562      563      564      565      566      567      568 
## 2.780679 2.583019 4.338133 5.693779 2.425601 3.815985 2.425601 2.640530 
##      569      570      571      572      573      574      575      576 
## 2.416141 5.390706 6.401417 1.772720 4.594136 2.261046 4.979854 3.388250 
##      577      578      579      580      581      582      583      584 
## 4.594136 4.046382 4.268858 2.439625 2.442453 2.640530 3.044838 3.104255 
##      585      586      587      588      589      590      591      592 
## 2.460203 5.095641 2.585569 4.076899 5.893069 3.925161 4.831798 1.728469 
##      593      594      595      596      597      598      599      600 
## 4.761255 3.483327 3.394072 2.083291 7.538828 3.492475 2.424284 2.005166 
##      601      602      603      604      605      606      607      608 
## 4.518854 1.401568 1.771359 4.831798 4.196988 3.585372 2.825218 5.252781 
##      609      610      611      612      613      614      615      616 
## 1.925675 3.388250 1.401568 5.321972 5.656911 3.774603 6.491151 4.068335 
##      617      618      619      620      621      622      623      624 
## 3.299167 1.000000 7.514827 5.404912 4.196988 5.071593 4.195467 5.191890 
##      625      626      627      628      629      630      631      632 
## 4.426142 3.925161 4.771164 3.947763 2.780679 5.114122 3.585372 5.430512 
##      633      634      635      636      637      638      639      640 
## 5.496406 5.191890 4.593344 4.413725 1.936919 4.072576 3.096935 2.825218 
##      641      642      643      644      645      646      647      648 
## 6.186807 5.988313 4.836321 2.319630 3.336831 3.216439 3.707926 2.728120 
##      649      650      651      652      653      654      655      656 
## 4.847755 4.612186 3.591637 1.604555 4.209482 2.788617 3.422010 6.445090 
##      657      658      659      660      661      662      663      664 
## 4.656121 3.842257 4.594136 2.687766 2.534709 4.076899 1.949157 2.439625 
##      665      666      667      668      669      670      671      672 
## 2.534709 5.054767 3.330906 5.379491 6.368887 6.243980 5.154903 2.188416 
##      673      674      675      676      677      678      679      680 
## 4.907264 1.771359 5.588177 3.330906 4.335114 5.191890 5.774271 5.276986 
##      681      682      683      684      685      686      687      688 
## 3.104255 1.676180 4.656121 1.161979 4.878890 3.937095 4.692053 5.693779 
##      689      690      691      692      693      694      695      696 
## 3.067221 2.405696 5.588177 4.979854 4.656121 4.531596 1.768468 6.243980 
##      697      698      699      700      701      702      703      704 
## 3.395344 4.141673 3.613683 4.671534 2.788617 2.862827 4.050899 3.707926 
##      705      706      707      708      709      710      711      712 
## 4.836321 3.902881 5.747597 1.161979 3.485172 4.068335 4.943371 4.122570 
##      713      714      715      716      717      718      719      720 
## 5.058096 6.491151 3.671784 5.209612 4.253283 5.550852 3.449885 2.814923 
##      721      722      723      724      725      726      727      728 
## 4.345282 5.588177 3.320862 4.277782 4.183637 4.183637 4.140749 5.433663 
##      729      730      731      732      733      734      735      736 
## 4.268858 4.856527 5.686621 1.904785 3.754003 3.795430 5.747597 2.583019 
##      737      738      739      740      741      742      743      744 
## 5.245732 3.399823 2.408508 3.920133 7.514827 5.653166 5.554685 3.899300 
##      745      746      747      748      749      750      751      752 
## 3.231919 6.117575 3.394072 3.367698 4.166267 4.166267 4.140749 2.083291 
##      753      754      755      756      757      758      759      760 
## 5.033715 4.856527 3.754003 1.657985 5.893069 4.671534 4.698027 1.711550 
##      761      762      763      764      765      766      767      768 
## 1.768468 5.321972 2.814923 4.665274 6.243980 4.003961 3.498291 1.936919 
##      769      770      771      772      773      774      775      776 
## 2.910850 3.842257 5.033715 6.445090 5.276986 4.878890 4.944902 2.460203 
##      777      778      779      780      781      782      783      784 
## 3.468940 2.910850 3.336831 5.704308 3.585372 3.285161 4.304280 2.188416 
##      785      786      787      788      789      790      791      792 
## 4.665274 4.449444 5.747597 6.186807 5.095641 2.442453 2.190671 4.356740 
##      793      794      795      796      797      798      799      800 
## 5.407552 5.774271 5.684293 4.138848 4.199687 2.274866 3.492446 2.886844 
##      801      802      803      804      805      806      807      808 
## 4.199687 3.585372 3.320862 2.862827 1.772720 5.731995 2.862827 4.671534 
##      809      810      811      812      813      814      815      816 
## 1.401568 5.433663 4.692053 5.893069 4.692053 2.699381 1.768468 1.161979 
##      817      818      819      820      821      822      823      824 
## 1.657985 2.825218 3.096781 3.929925 4.771164 5.653166 4.622727 3.795430 
##      825      826      827      828      829      830      831      832 
## 4.224940 5.602642 5.227656 4.588102 3.468940 3.692119 3.471615 5.114122 
##      833      834      835      836      837      838      839      840 
## 6.764856 1.595488 3.868065 2.405696 4.138848 4.811851 4.238259 6.368887 
##      841      842      843      844      845      846      847      848 
## 3.067221 4.209482 3.104255 5.600864 4.166267 2.699381 2.261046 7.538828 
##      849      850      851      852      853      854      855      856 
## 5.553832 5.460654 7.021804 2.083291 5.460654 2.910850 1.536774 4.943371 
##      857      858      859      860      861      862      863      864 
## 4.253283 5.075186 3.984218 5.071593 3.390674 2.140751 1.513965 3.330906 
##      865      866      867      868      869      870      871      872 
## 7.346630 2.439625 2.280837 3.783557 4.046382 2.005166 2.687766 3.920133 
##      873      874      875      876      877      878      879      880 
## 5.459415 5.704308 3.868065 3.069414 4.449444 4.588102 3.783557 1.878040 
##      881      882      883      884      885      886      887      888 
## 4.710552 2.005166 4.304280 5.653166 5.475266 1.161979 4.380097 2.572362 
##      889      890      891      892      893      894      895      896 
## 3.660555 4.518854 6.491151 3.255376 5.344676 3.937095 3.939963 4.138848 
##      897      898      899      900      901      902      903      904 
## 6.764856 4.905199 2.261046 3.422010 5.686621 5.252781 4.345282 2.140751 
##      905      906      907      908      909      910      911      912 
## 4.593344 4.518854 3.660555 5.496406 2.572362 3.395344 4.684075 4.875619 
##      913      914      915      916      917      918      919      920 
## 3.842257 4.809455 6.401417 5.407552 2.958708 5.229079 6.024135 2.687766 
##      921      922      923      924      925      926      927      928 
## 2.425601 4.331234 1.556224 4.727722 5.227656 2.687766 5.654608 7.021804 
##      929      930      931      932      933      934      935      936 
## 1.595488 3.492446 5.379491 4.622727 3.485172 4.243020 5.175330 3.613683 
##      937      938      939      940      941      942      943      944 
## 5.459415 3.774603 3.471615 2.442453 3.231919 2.640530 5.075186 2.439625 
##      945      946      947      948      949      950      951      952 
## 4.710552 3.104255 4.216169 5.344676 4.847755 1.878040 2.699381 4.806439 
##      953      954      955      956      957      958      959      960 
## 2.309547 3.395344 5.154903 1.401568 5.245732 1.851350 5.430512 5.390706 
##      961      962      963      964 
## 4.082223 3.264194 4.243020 3.471615 
## 
## $`Setelah transformasi~Uji Kolmogorov-Smirnov`
##     P.Value                       Keputusan
## 1 0.0740086 Terima H0, data menyebar normal

Hasil menunjukkan bahwa p-value > α=5% sehingga tak tolak H0 atau tidak cukup bukti untuk menyatakan bahwa sisaan tidak menyebar normal. Dengan kata lain, asumsi normalitas sisaan terpenuhi.

Homoskedastisitas dan Non-Autokorelasi

par(mfrow=c(1,2))
plot(model.stepwise,c(1,3))

gqtest(model.stepwise)
## 
##  Goldfeld-Quandt test
## 
## data:  model.stepwise
## GQ = 1.0619, df1 = 471, df2 = 471, p-value = 0.2573
## alternative hypothesis: variance increases from segment 1 to 2
bgtest(model.stepwise)
## 
##  Breusch-Godfrey test for serial correlation of order up to 1
## 
## data:  model.stepwise
## LM test = 0.029058, df = 1, p-value = 0.8646

Homoskedastisitas dan non-autokorelasi pada sisaan terpenuhi (p-value > 0,05)

REGRESI RIDGE

lapply(c("glmnet","lmridge"),library,character.only=T)[[1]]
## Loading required package: Matrix
## Loaded glmnet 4.1-8
## 
## Attaching package: 'lmridge'
## The following object is masked from 'package:car':
## 
##     vif
##  [1] "glmnet"       "Matrix"       "rcompanion"   "kSamples"     "SuppDists"   
##  [6] "fitdistrplus" "survival"     "MASS"         "olsrr"        "lmtest"      
## [11] "zoo"          "car"          "carData"      "stats"        "graphics"    
## [16] "grDevices"    "utils"        "datasets"     "methods"      "base"

Pakai glmnet

x <- cbind(x1.baru,x2.baru,x3.baru,x4.baru,x5.baru,x6.baru,x7.baru,x8.baru,x9.baru,x10.baru,x11.baru,x12.baru,x13.baru)
head(x)
##      x1.baru x2.baru x3.baru x4.baru x5.baru x6.baru x7.baru x8.baru x9.baru
## [1,]      52       1       0     125     212       0       1     168       0
## [2,]      53       1       0     140     203       1       0     155       1
## [3,]      70       1       0     145     174       0       1     125       1
## [4,]      61       1       0     148     203       0       1     161       0
## [5,]      62       0       0     138     294       1       1     106       0
## [6,]      58       0       0     100     248       0       0     122       0
##      x10.baru x11.baru x12.baru x13.baru
## [1,]      1.0        2        2        3
## [2,]      3.1        0        0        3
## [3,]      2.6        0        0        3
## [4,]      0.0        2        1        3
## [5,]      1.9        1        3        2
## [6,]      1.0        1        0        2
y <- y.baru
head(y)
## [1] 0 0 0 0 0 1
library(glmnet)
cv.r<-cv.glmnet(x,y,alpha=0);plot(cv.r)

best.lr <- cv.r$lambda.min
ridge1 <- glmnet(x,y,alpha=0,lambda=best.lr)
coef(ridge1)
## 14 x 1 sparse Matrix of class "dgCMatrix"
##                        s0
## (Intercept)  0.8185968424
## x1.baru     -0.0009311693
## x2.baru     -0.2015610981
## x3.baru      0.1049972989
## x4.baru     -0.0011383153
## x5.baru     -0.0004369786
## x6.baru     -0.0055399043
## x7.baru      0.0315308584
## x8.baru      0.0031880599
## x9.baru     -0.1308416008
## x10.baru    -0.0486776293
## x11.baru     0.0983858906
## x12.baru    -0.1131000466
## x13.baru    -0.1737622899

Diperoleh model:

\[y = 0.8185968424 - 0.0009311693x_1 - 0.2015610981x_2 + 0.1049972989x_3 - 0.0011383153x_4 - 0.0004369786x_5 - 0.0055399043x_6 + 0.0315308584x_7 + 0.0031880599x_8 - 0.1308416008x_9 - 0.0486776293x_{10} + 0.0983858906x_{11} - 0.1131000466x_{12} - 0.1737622899x_{13} \]

#Fungsi R-squared
rsq<-function(bestmodel,bestlambda,x,y){
 #y duga
 y.duga <- predict(bestmodel, s = bestlambda, newx = x)

 #JKG dan JKT
 jkt <- sum((y - mean(y))^2)
 jkg <- sum((y.duga- y)^2)

#find R-Squared
rsq <- 1 - jkg/jkt
return(rsq) 
}

rsq(ridge1,best.lr,x,y)
## [1] 0.585907

Diperoleh nilai R-squared 58,59%.

Pakai lmridge

dataridge <- cbind.data.frame(y.baru,x1.baru,x2.baru,x3.baru,x4.baru,x5.baru,x6.baru,x7.baru,x8.baru,x9.baru,x10.baru,x11.baru,x12.baru,x13.baru)
head(dataridge)
##   y.baru x1.baru x2.baru x3.baru x4.baru x5.baru x6.baru x7.baru x8.baru
## 1      0      52       1       0     125     212       0       1     168
## 2      0      53       1       0     140     203       1       0     155
## 3      0      70       1       0     145     174       0       1     125
## 4      0      61       1       0     148     203       0       1     161
## 5      0      62       0       0     138     294       1       1     106
## 6      1      58       0       0     100     248       0       0     122
##   x9.baru x10.baru x11.baru x12.baru x13.baru
## 1       0      1.0        2        2        3
## 2       1      3.1        0        0        3
## 3       1      2.6        0        0        3
## 4       0      0.0        2        1        3
## 5       0      1.9        1        3        2
## 6       0      1.0        1        0        2
library(lmridge)
ridge2 <- lmridge(y.baru ~ x1.baru+x2.baru+x3.baru+x4.baru+x5.baru+x6.baru+x7.baru+x8.baru+x9.baru+x10.baru+x11.baru+x12.baru+x13.baru,dataridge,scaling="centered")
plot(ridge2)

vif(ridge2)
##     x1.baru x2.baru x3.baru x4.baru x5.baru x6.baru x7.baru x8.baru x9.baru
## k=0   2e-05  0.0058 0.00129       0       0 0.00959 0.00431       0  0.0066
##     x10.baru x11.baru x12.baru x13.baru
## k=0  0.00137   0.0047  0.00127  0.00343
summary(ridge2)
## 
## Call:
## lmridge.default(formula = y.baru ~ x1.baru + x2.baru + x3.baru + 
##     x4.baru + x5.baru + x6.baru + x7.baru + x8.baru + x9.baru + 
##     x10.baru + x11.baru + x12.baru + x13.baru, data = dataridge, 
##     scaling = "centered")
## 
## 
## Coefficients: for Ridge parameter K= 0 
##           Estimate Estimate (Sc) StdErr (Sc) t-value (Sc) Pr(>|t|)    
## Intercept   0.8197        0.8197      0.1690       4.8493   <2e-16 ***
## x1.baru    -0.0006       -0.0007      0.0014      -0.4786   0.6323    
## x2.baru    -0.2106       -0.2106      0.0246      -8.5486   <2e-16 ***
## x3.baru     0.1095        0.1095      0.0116       9.4147   <2e-16 ***
## x4.baru    -0.0012       -0.0012      0.0007      -1.8218   0.0688 .  
## x5.baru    -0.0005       -0.0005      0.0002      -1.9908   0.0468 *  
## x6.baru    -0.0049       -0.0049      0.0317      -0.1541   0.8776    
## x7.baru     0.0306        0.0306      0.0212       1.4392   0.1504    
## x8.baru     0.0033        0.0033      0.0006       5.4196   <2e-16 ***
## x9.baru    -0.1283       -0.1283      0.0263      -4.8793   <2e-16 ***
## x10.baru   -0.0472       -0.0472      0.0120      -3.9424   0.0001 ***
## x11.baru    0.1037        0.1037      0.0222       4.6777   <2e-16 ***
## x12.baru   -0.1187       -0.1187      0.0115     -10.2783   <2e-16 ***
## x13.baru   -0.1800       -0.1800      0.0189      -9.5046   <2e-16 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Ridge Summary
##          R2      adj-R2    DF ridge           F         AIC         BIC 
##     0.58640     0.58120    13.00051   103.72028 -2162.97662  4524.08206 
## Ridge minimum MSE= 0.004017763 at K= 0 
## P-value for F-test ( 13.00051 , 950.9989 ) = 4.854977e-172 
## -------------------------------------------------------------------

Diperoleh model:

\[y = 0.8197 - 0.0006x_1 - 0.2106x_2 + 0.1095x_3 - 0.0012x_4 - 0.0005x_5 - 0.0049x_6 + 0.0306x_7 + 0.0033x_8 - 0.1283x_9 - 0.0472x_{10} + 0.1037x_{11} - 0.1187x_{12} - vx_{13} \]

Diketahui peubah x1, x4, x6, dan x7 tidak berpengaruh signifikan terhadap peubah y pada model ini.

REGRESI LASSO

cv.l <- cv.glmnet(x,y,alpha=1);plot(cv.l)

best.ll<-cv.l$lambda.min
lasso<-glmnet(x,y,alpha=1,lambda=best.ll)
coef(lasso)
## 14 x 1 sparse Matrix of class "dgCMatrix"
##                        s0
## (Intercept)  0.8022736903
## x1.baru     -0.0006054159
## x2.baru     -0.2069681478
## x3.baru      0.1082865603
## x4.baru     -0.0011575125
## x5.baru     -0.0004320266
## x6.baru     -0.0009880365
## x7.baru      0.0289848139
## x8.baru      0.0032475834
## x9.baru     -0.1280434311
## x10.baru    -0.0472376826
## x11.baru     0.1020847376
## x12.baru    -0.1181967076
## x13.baru    -0.1787333453

Diperoleh model:

\[y = 0.7811930062 - 0.0005428009x_1 - 0.2028381565x_2 + 0.1071349655x_3 - 0.0010756846x_4 - 0.0004005884x_5 + 0.0270610189x_7 + 0.0032299498x_8 - 0.1275548574x_9 - 0.0473143997x_{10} + 0.1001968298x_{11} - 0.1175102931x_{12} - 0.1774380229x_{13} \]

rsq(lasso,best.ll,x,y)
## [1] 0.5863303

Diketahui adanya seleksi pada model yaitu tereliminasinya peubah x6 dengan nilai R-squared 58,61%.

RSE (Residual Standard Error) Model Regresi Ridge dan Model Regresi LASSO

Model Regresi Ridge

# Prediksi model ridge pada data pelatihan
train_predictionsridge <- predict(ridge2,newx = x)

# Hitung residu (selisih antara prediksi dan nilai sebenarnya)
residualsridge <- y - train_predictionsridge

# Hitung varian residu
dfridge <- length(y) - length(ridge2$beta)
residual_varianceridge <- sum(residualsridge^2) / dfridge

# Hitung RSE
rseridge <- sqrt(residual_varianceridge)

# Tampilkan hasil RSE
print(paste("Residual Standard Error (RSE):",rseridge))
## [1] "Residual Standard Error (RSE): 0.321307802742746"

Model Regresi LASSO

# Prediksi model Lasso pada data pelatihan
train_predictionsLasso <- predict(lasso,newx = x)

# Hitung residu (selisih antara prediksi dan nilai sebenarnya)
residualsLasso <- y - train_predictionsLasso

# Hitung varian residu
dfLasso <- length(y) - length(lasso$beta)
residual_varianceLasso <- sum(residualsLasso^2) / dfLasso

# Hitung RSE
rseLasso <- sqrt(residual_varianceLasso)

# Tampilkan hasil RSE
print(paste("Residual Standard Error (RSE):",rseLasso))
## [1] "Residual Standard Error (RSE): 0.323524690910896"

PERBANDINGAN MODEL

RSE Model Awal (setelah penagnganan pencilan) : 0.3237

RSE Model Stepwise : 0.3236

RSE Model Ridge : 0.3213

RSE Model LASSO : 0.3236

INTERPRETASI

Penentuan model terbaik akan dipilih berdasarkan nilai RSE (residual standard error) terkecil. Pada kasus ini, model yang paling optimal adalah Model Regresi Ridge. Diketahui juga data tidak mengandung multikolinearitas sehingga tidak diperlukan adanya seleksi peubah. Hal ini terbukti dalam regresi ridge yang mempertahankan semua peubah penjelasnya, sehingga peubah-peubah tersebut tetap digunakan dalam model regresi.