Directions

The objective of this assignment is to introduce you to R and R markdown and to complete some basic data simulation exercises.

Please include all code needed to perform the tasks. This is an R Markdown document. Markdown is a simple formatting syntax for authoring HTML, PDF, and MS Word documents. For more details on using R Markdown see http://rmarkdown.rstudio.com.

To submit this homework you will create the document in Rstudio, using the knitr package (button included in Rstudio) and then submit the document to your Rpubs account. Once uploaded you will submit the link to that document on Moodle. Please make sure that this link is hyperlinked and that I can see the visualization and the code required to create it.

Questions

  1. Simulate data for 30 draws from a normal distribution where the means and standard deviations vary among three distributions.
set.seed(300)
rnorm(30, mean = c(0,5,10), sd = c(4,10,18))
##  [1]   5.495164  13.621069  18.522804   2.805051   4.149447  38.236638
##  [7]   3.269568   8.947686  31.828574   1.420323  27.162742   8.370273
## [13]  -5.266112   5.665348  19.219107   0.200119  19.673972 -13.211369
## [19]  -1.030766   7.930513   3.926435   2.533032   1.868214  12.428076
## [25]  -4.579020   1.886018  14.228351   5.354695   4.006378  28.664188
  1. Simulate 2 continuous variables (normal distribution) (n=20) and plot the relationship between them
X1=rnorm(20,mean=0,sd=1)
X2=rnorm(20,mean=0,sd=1)
plot(X1~X2)

  1. Simulate 3 variables (x1, x2 and y). x1 and x2 should be drawn from a uniform distribution and y should be drawn from a normal distribution. Fit a multiple linear regression.
set.seed(300)
x1 = runif(100, min = 0, max = 1)
x2 = runif(100, min = 50, max = 100)
y = rnorm(100, mean = 100, sd = 200)
lm(y ~ x1 + x2)
## 
## Call:
## lm(formula = y ~ x1 + x2)
## 
## Coefficients:
## (Intercept)           x1           x2  
##    131.2672      39.0462      -0.3189
  1. Simulate 3 letters repeating each letter twice, 2 times.
rep(letters[2:4], each = 2, times =2)
##  [1] "b" "b" "c" "c" "d" "d" "b" "b" "c" "c" "d" "d"
  1. Create a dataframe with 3 groups, 2 factors and two quantitative response variables. Use the replicate function (n = 25).
data.frame(group = rep(letters[2:4]),
                       factor = rep(LETTERS[1:2]),x = rnorm(60, mean =5, sd=3), y = rnorm(60, mean = 15, sd =10))
##    group factor          x          y
## 1      b      A  8.1330283  16.053435
## 2      c      B -2.1242363  24.264978
## 3      d      A  4.4814803  17.117219
## 4      b      B 10.4463761   3.399281
## 5      c      A  3.8505541  23.237738
## 6      d      B  2.6065334  29.283453
## 7      b      A  2.0211903  11.030972
## 8      c      B -0.3665134  -2.947162
## 9      d      A  8.5149705   7.375006
## 10     b      B  2.5759629  13.114750
## 11     c      A  2.9281414   2.599585
## 12     d      B  2.0639907   1.341067
## 13     b      A  6.8130158  24.279705
## 14     c      B  7.0416926  39.035403
## 15     d      A  2.2437711  12.395507
## 16     b      B  6.0499605   4.954977
## 17     c      A  8.9685162   6.270899
## 18     d      B  7.9743273   5.529763
## 19     b      A  5.9085361  21.767418
## 20     c      B  2.5380284 -16.425972
## 21     d      A  5.8029407  16.413481
## 22     b      B  3.1457546  16.717194
## 23     c      A -0.9226167  26.004767
## 24     d      B  3.7078095  27.750845
## 25     b      A  3.2365745   3.421114
## 26     c      B  3.3289279  24.404386
## 27     d      A -0.2439076  -5.849829
## 28     b      B  4.0327120  10.401353
## 29     c      A  0.4234821   5.340665
## 30     d      B  1.7611799  10.687284
## 31     b      A  3.3964023  21.947766
## 32     c      B  1.1126575  13.666098
## 33     d      A 15.5124226   5.055455
## 34     b      B  9.6071274   1.130144
## 35     c      A  1.7184013   5.782464
## 36     d      B  5.4539961   4.093898
## 37     b      A -0.3536090  11.825729
## 38     c      B  3.5654138  22.041320
## 39     d      A  2.4960854  16.521464
## 40     b      B  2.9770579  -1.718889
## 41     c      A  8.9683358  39.976913
## 42     d      B  6.6418132  22.888032
## 43     b      A -1.3817656   1.466668
## 44     c      B  3.1770986  12.977920
## 45     d      A  7.2190703   5.210985
## 46     b      B  9.7395380   4.085985
## 47     c      A  2.6238806   7.048133
## 48     d      B  4.7362789  16.896287
## 49     b      A  7.0797103  11.693749
## 50     c      B  8.4456995   3.495470
## 51     d      A  7.3501475  20.981640
## 52     b      B  9.8068564  38.295432
## 53     c      A  5.4906941   5.737993
## 54     d      B  4.9671220  22.582676
## 55     b      A  7.3276913  19.800254
## 56     c      B  9.3259904  35.261985
## 57     d      A  3.4333643   7.669852
## 58     b      B  8.8644089  18.258907
## 59     c      A 10.0820753   2.529527
## 60     d      B  5.6744274  10.588737
simulate <- replicate(3, expr = data.frame(group = rep(letters[2:4]),factor = rep(LETTERS[1:2]),x = rnorm(60, mean =5, sd=3),y = rnorm(60, mean = 15, sd =10)),simplify = FALSE)
simulate
## [[1]]
##    group factor          x          y
## 1      b      A  3.9650584 -1.7231944
## 2      c      B  5.9596677 19.7679055
## 3      d      A  0.5625022 11.9689096
## 4      b      B  4.8588309 23.3471366
## 5      c      A  4.4905708 22.9712584
## 6      d      B  6.2718199  9.8891125
## 7      b      A  9.4197248 20.0836720
## 8      c      B  6.9006073  9.7128128
## 9      d      A  7.7516581 23.5367446
## 10     b      B  2.5318829  0.5959490
## 11     c      A  6.3176834 17.3151701
## 12     d      B  0.6352415 17.5895195
## 13     b      A  3.1212168 14.9061675
## 14     c      B -2.4645661 14.1571420
## 15     d      A  5.5828525 13.5955684
## 16     b      B  6.6669902 12.2695439
## 17     c      A  6.7116115 20.3994319
## 18     d      B  6.2382541 13.3469971
## 19     b      A  2.6638289 39.7068458
## 20     c      B  5.9246907  6.9432870
## 21     d      A  7.3385355 22.1765517
## 22     b      B 11.6588626 18.8882149
## 23     c      A  8.5964587 24.2417995
## 24     d      B  7.3752961  2.1877804
## 25     b      A  3.5630013 21.2474493
## 26     c      B  8.9621337 22.7703323
## 27     d      A  8.1427950 12.6549833
## 28     b      B  2.8547352 23.2791801
## 29     c      A  5.3014752 13.5679940
## 30     d      B  7.0293797 19.9097990
## 31     b      A  1.9506471 20.4338341
## 32     c      B  8.1447864 22.3154312
## 33     d      A  3.3173572 27.5758051
## 34     b      B  1.3125283  4.6220470
## 35     c      A  2.9546562 17.8583800
## 36     d      B  7.0813334 27.0170885
## 37     b      A  1.2100130 26.5330411
## 38     c      B 13.9701880 20.3627588
## 39     d      A  3.5803915 16.6624219
## 40     b      B  4.3734138 11.8515775
## 41     c      A  4.0304108 24.1464450
## 42     d      B  4.5927390 22.8631058
## 43     b      A  4.8342233 25.0191862
## 44     c      B  4.3033598 21.6197502
## 45     d      A  8.4365494 18.8581002
## 46     b      B  4.0502607 23.9296663
## 47     c      A  1.4159048  7.0012554
## 48     d      B  5.5789724 18.9615987
## 49     b      A  7.5205957 22.6097213
## 50     c      B  6.7758249  8.2236018
## 51     d      A  3.2413183 21.2040359
## 52     b      B  4.0898702  7.6270620
## 53     c      A  5.8770459 -0.2131952
## 54     d      B  4.4282912 39.6282907
## 55     b      A  9.2777093 27.0364059
## 56     c      B  6.2297653 15.3825674
## 57     d      A  4.9061190 26.4235400
## 58     b      B  3.2738048 13.6293519
## 59     c      A  2.8826320 17.2965472
## 60     d      B  2.0224662  3.5319231
## 
## [[2]]
##    group factor           x          y
## 1      b      A  1.67981226  8.9627119
## 2      c      B  6.90304769 16.7495000
## 3      d      A  7.76321299 20.7901921
## 4      b      B  3.42806026 12.6495698
## 5      c      A  7.16114622 17.3151515
## 6      d      B  3.38173617 43.9874077
## 7      b      A  1.85065206  8.1303615
## 8      c      B  4.87119878 -4.9692778
## 9      d      A  5.96844765  9.7480063
## 10     b      B  4.51023060 11.5991956
## 11     c      A  8.20212378 16.8691973
## 12     d      B  5.90927821  7.4314160
## 13     b      A  6.38474095 28.6457749
## 14     c      B  3.86629839 32.2778395
## 15     d      A  0.06048081 18.8664119
## 16     b      B -1.59743290  6.8972228
## 17     c      A  7.36937742 16.5681191
## 18     d      B 11.89006552  2.4630421
## 19     b      A  4.87425361  6.8283850
## 20     c      B  5.55059398 19.1460700
## 21     d      A  1.09223712 31.4858791
## 22     b      B  4.26782510 12.4117014
## 23     c      A  2.15469809 11.2287902
## 24     d      B  5.76164899 13.5379357
## 25     b      A  3.10597497 13.2646526
## 26     c      B  4.29081414 -0.2523517
## 27     d      A 12.22349396 24.3874151
## 28     b      B  7.78682865 14.0118979
## 29     c      A  9.72422481 13.9900617
## 30     d      B  6.62256789 -2.6074715
## 31     b      A  4.70265052 22.2798879
## 32     c      B  8.34249032 21.1457019
## 33     d      A  4.30023430  3.0629273
## 34     b      B  4.29663248 10.4837950
## 35     c      A  3.18274792 22.9802117
## 36     d      B  5.38181216 33.3491399
## 37     b      A  8.46135834 13.0117147
## 38     c      B  3.31009276 31.4902287
## 39     d      A  0.74325106 10.9501040
## 40     b      B  5.70509576 30.9259154
## 41     c      A  5.08435163 22.8741196
## 42     d      B -0.83782790 12.2563852
## 43     b      A  5.14909918 26.3047843
## 44     c      B  7.68746973  9.6525500
## 45     d      A 10.35659711 16.8448366
## 46     b      B  5.97600724 11.2669802
## 47     c      A  2.06801366 19.2508503
## 48     d      B  4.90865529  4.1067644
## 49     b      A  5.28184481 11.0405287
## 50     c      B  6.30721598 10.8214511
## 51     d      A -0.65047030 11.0063514
## 52     b      B  2.95915970 17.1431218
## 53     c      A  1.75492160  6.7521368
## 54     d      B -0.32769146 25.0368761
## 55     b      A  1.20849588 -1.0383898
## 56     c      B  6.96241196 15.5427622
## 57     d      A  9.37165241 13.4100376
## 58     b      B  3.69714978  9.9238619
## 59     c      A -0.77797183 12.3513264
## 60     d      B  4.18237868 21.4362984
## 
## [[3]]
##    group factor           x            y
## 1      b      A  4.74898491  17.10959101
## 2      c      B  8.01414362   3.78983056
## 3      d      A  4.60283807   1.64607711
## 4      b      B  5.76452997  19.94876965
## 5      c      A  2.76397381  12.71522569
## 6      d      B  2.13232047  17.27455517
## 7      b      A  8.53026400  -6.59710770
## 8      c      B  1.92651297  -0.81156900
## 9      d      A  2.81779706  15.68617095
## 10     b      B  6.92695569  19.13785290
## 11     c      A  5.74029789  19.00575550
## 12     d      B  7.62368574  22.46138162
## 13     b      A  4.72218824  21.47971413
## 14     c      B  4.48977717  -1.30168692
## 15     d      A  1.53333894  14.73683744
## 16     b      B  5.50545826  20.25498694
## 17     c      A  3.34522987   0.22863356
## 18     d      B  7.25990147  28.91852708
## 19     b      A  0.58075831   5.71538457
## 20     c      B  7.55119150   2.09091305
## 21     d      A  5.35150890  14.56184274
## 22     b      B  2.64432413  -8.30717847
## 23     c      A  0.07939278  11.27929066
## 24     d      B  0.70454907  23.56536519
## 25     b      A  3.86214353  18.35102012
## 26     c      B  7.08529008  26.83200244
## 27     d      A  9.97456742  36.22473096
## 28     b      B  8.02922724  16.81278826
## 29     c      A  6.23177734  35.09793170
## 30     d      B  0.90038994   2.50705783
## 31     b      A  2.91277797  30.85823324
## 32     c      B  4.20409741  21.24158801
## 33     d      A  7.06308337  25.65892137
## 34     b      B  5.53757283  13.59403225
## 35     c      A 14.02529382  -1.41988304
## 36     d      B  9.24343415  11.70454400
## 37     b      A  6.35934858  27.94162008
## 38     c      B  1.46613330  22.69541719
## 39     d      A  7.58555815  24.70914173
## 40     b      B  1.19511979  12.45012679
## 41     c      A  6.29269268  14.96277947
## 42     d      B  5.09574698  -0.94324583
## 43     b      A  3.15561090  -0.05677246
## 44     c      B  7.71493702  -7.47979370
## 45     d      A  4.99259532  23.85912301
## 46     b      B  3.61116224  31.32828212
## 47     c      A  3.58297133  -0.30505688
## 48     d      B  5.61340297  25.08757738
## 49     b      A  7.32914169   9.32525245
## 50     c      B  6.71018971  20.84830693
## 51     d      A  6.30694340  31.61123728
## 52     b      B  5.84238196  15.75536161
## 53     c      A  5.21903120  26.12427992
## 54     d      B  3.48577109 -16.72029706
## 55     b      A  7.32354879  32.31637717
## 56     c      B  6.18029139  14.94686506
## 57     d      A  3.34368637   2.83360973
## 58     b      B  3.37276077   0.54719610
## 59     c      A  1.89098721   3.19330862
## 60     d      B  0.55532572   1.19541712
simulate <- replicate(3, expr = data.frame(group = rep(letters[2:4]),factor = rep(LETTERS[1:2]),x = rnorm(60, mean =5, sd=3),y = rnorm(60, mean = 15, sd =10)),simplify = FALSE)
simulate
## [[1]]
##    group factor         x           y
## 1      b      A  5.815165 -1.61708441
## 2      c      B  3.275532 25.08822628
## 3      d      A  2.586307  3.10415376
## 4      b      B  5.617827 -8.51830284
## 5      c      A  7.284343  3.47338574
## 6      d      B  5.380332 -0.89948476
## 7      b      A  4.303481  7.15079497
## 8      c      B  2.572327 22.93969156
## 9      d      A  1.345583 27.88910445
## 10     b      B  3.839355 19.04541359
## 11     c      A  7.925749 27.59553832
## 12     d      B  4.901023 28.77246329
## 13     b      A  7.842530 23.97441511
## 14     c      B  5.339202 31.75331678
## 15     d      A  7.326968 20.66070099
## 16     b      B  7.403216 -2.88267416
## 17     c      A 12.214611  8.30782169
## 18     d      B  3.075111 12.30644802
## 19     b      A 10.374530 -0.08911894
## 20     c      B  5.932746 33.73910844
## 21     d      A  1.013353 32.84100616
## 22     b      B  7.849398 39.01810886
## 23     c      A  6.667709 28.55309407
## 24     d      B  8.702884 21.64732556
## 25     b      A  6.464381 23.71738677
## 26     c      B  3.722307  7.81705331
## 27     d      A  2.851478 10.50507413
## 28     b      B  4.116453  0.76860723
## 29     c      A  8.313267 13.62326583
## 30     d      B  3.710091 29.90166190
## 31     b      A  4.632794 10.78122828
## 32     c      B  4.301034 16.01242467
## 33     d      A  4.958963 24.53095298
## 34     b      B  4.673809  8.18155892
## 35     c      A  5.515694 29.77286987
## 36     d      B  2.010016 27.02332101
## 37     b      A  5.284673 23.88369085
## 38     c      B  3.757055  9.26943013
## 39     d      A  7.999686 28.84159866
## 40     b      B  3.338982 21.91036025
## 41     c      A  5.865286 14.52013145
## 42     d      B  5.103818 10.45017916
## 43     b      A  1.311780 -2.17701127
## 44     c      B  9.778198  9.53048068
## 45     d      A  1.067100 36.48291662
## 46     b      B  4.347159  8.54210400
## 47     c      A  4.541457  5.89755801
## 48     d      B  6.281625 23.15323869
## 49     b      A  7.427289  4.85759089
## 50     c      B  6.155896  8.80895114
## 51     d      A  2.412833 20.94874301
## 52     b      B  1.710740 21.71241019
## 53     c      A  5.328405 26.32494011
## 54     d      B  7.013583 15.18361430
## 55     b      A  1.940115 29.36650177
## 56     c      B  8.140917 22.91764547
## 57     d      A  3.573834 25.76248602
## 58     b      B  1.897875 16.28004710
## 59     c      A -1.172073  4.64020358
## 60     d      B  4.379428 33.49104171
## 
## [[2]]
##    group factor          x         y
## 1      b      A  6.6073886 14.873919
## 2      c      B 10.4826600  7.031971
## 3      d      A  5.3749472 15.430715
## 4      b      B  4.2390393 20.575914
## 5      c      A  3.9086876 19.229255
## 6      d      B  9.3002081 19.902845
## 7      b      A  5.8688948  1.660762
## 8      c      B  6.0248779 29.503029
## 9      d      A  2.7566973 -4.731682
## 10     b      B  6.1158761  6.728312
## 11     c      A  3.6931420 12.893551
## 12     d      B  6.2540259 -4.375077
## 13     b      A  3.0756134 15.229020
## 14     c      B  8.3494436 11.571990
## 15     d      A -0.4364417  8.401219
## 16     b      B  4.1004596 15.909592
## 17     c      A -1.5874469 17.104413
## 18     d      B  6.3062963 10.046832
## 19     b      A -2.5457833 31.399828
## 20     c      B  6.0198118 15.187497
## 21     d      A  8.8348900 11.329076
## 22     b      B  5.8201163  1.535103
## 23     c      A -1.8320123 26.039093
## 24     d      B  1.6074172 12.783545
## 25     b      A  3.8247513 16.503807
## 26     c      B  3.0202080 12.861533
## 27     d      A  4.9270145 26.767054
## 28     b      B  8.2420378 13.002316
## 29     c      A 10.3161438 19.050893
## 30     d      B  5.9506308 14.171664
## 31     b      A  5.3427701 18.029402
## 32     c      B  2.5743825  8.715358
## 33     d      A  5.2133312 13.393968
## 34     b      B  9.7900999 16.405056
## 35     c      A  0.5145843  5.771104
## 36     d      B  1.0948092 23.694824
## 37     b      A  5.1685294  6.675079
## 38     c      B  7.0021387 18.654123
## 39     d      A 10.7615837 20.072118
## 40     b      B  5.5851361 17.552401
## 41     c      A  1.8187687  6.273395
## 42     d      B -0.8212130 28.488112
## 43     b      A  3.9786634 12.502276
## 44     c      B  3.6823425 20.546942
## 45     d      A  3.7784604 -2.951947
## 46     b      B  5.8936576 13.158968
## 47     c      A  1.8892254 22.449477
## 48     d      B  1.0593072 32.001467
## 49     b      A  9.4360571 14.542597
## 50     c      B  1.3700556  9.508814
## 51     d      A  6.5166031  9.967639
## 52     b      B  4.4870378 23.270462
## 53     c      A  3.4930146 32.478850
## 54     d      B  4.0554166 -1.209938
## 55     b      A  2.2087883 -1.941274
## 56     c      B  6.1313107 18.547291
## 57     d      A  3.9248131 25.237982
## 58     b      B -3.6453649 22.013555
## 59     c      A -2.9285918  9.943649
## 60     d      B  1.6543954 23.346315
## 
## [[3]]
##    group factor          x           y
## 1      b      A  3.6224690   0.1999734
## 2      c      B  8.6725414  14.0039876
## 3      d      A  0.6233899  -4.0007000
## 4      b      B  5.3964575  30.4787792
## 5      c      A  7.3803853  20.5966568
## 6      d      B  8.6354800  13.9039546
## 7      b      A  6.9064448   6.3721051
## 8      c      B  6.4542617  44.8058615
## 9      d      A  9.8190330  13.7985569
## 10     b      B  7.3160904  35.0899257
## 11     c      A  8.4474446   9.1554031
## 12     d      B  6.4671776  33.7018737
## 13     b      A  7.1846029  18.9013656
## 14     c      B -1.4967970   6.5520777
## 15     d      A  9.3016010   2.1452659
## 16     b      B  1.8736478  19.6981730
## 17     c      A  3.5835723  32.4892496
## 18     d      B  3.2863897  13.2807678
## 19     b      A  3.3258108 -12.2819871
## 20     c      B  3.1954961  17.4660971
## 21     d      A  8.9514680  21.3970782
## 22     b      B  3.2081189   6.1209054
## 23     c      A  5.1078833  32.9491940
## 24     d      B  6.8576457  10.1336617
## 25     b      A  2.9576674   4.6198500
## 26     c      B  4.7741927  19.5242437
## 27     d      A  4.5672009  14.2586270
## 28     b      B  4.7681854  14.1850044
## 29     c      A  6.4740795  22.7880469
## 30     d      B  8.0916542  12.5344250
## 31     b      A  6.8048466  23.4515411
## 32     c      B  3.4714061  19.5977766
## 33     d      A  6.5316774  17.2670567
## 34     b      B  7.4439028  25.4194762
## 35     c      A  4.8850984   1.7203817
## 36     d      B 11.9665922  24.2307739
## 37     b      A -2.1587497  12.0740496
## 38     c      B  7.7813033  27.7808589
## 39     d      A  6.0175376  10.6278733
## 40     b      B -0.3633616 -14.4920023
## 41     c      A  4.0500952  28.2819778
## 42     d      B  5.2010839   4.2856227
## 43     b      A  3.7029928  22.8275874
## 44     c      B  2.1599655  16.4762960
## 45     d      A  3.3626318  23.3328532
## 46     b      B  5.7139194  18.8781788
## 47     c      A  7.8323719   4.1434827
## 48     d      B  8.1716108   6.6685523
## 49     b      A 10.2326297   2.1742216
## 50     c      B  2.9605151  34.7017368
## 51     d      A  5.6985781  13.3289435
## 52     b      B  2.6646266  11.0424101
## 53     c      A  9.9155198  24.1446218
## 54     d      B  9.8994927   5.2205480
## 55     b      A  4.6704713  12.5488689
## 56     c      B  2.2013094  35.6569671
## 57     d      A  2.9769509  12.5088877
## 58     b      B 10.3317791   6.1373590
## 59     c      A  2.0776865  23.8047144
## 60     d      B  7.1019413  15.1139607