Assignment 1

For all assignments, unless otherwise stated, your work will always consist of two files:

  • The .RMD file with the code (this file)
  • The .HTML file resulting from you knitting this file

All weekly assignments, unless otherwise noted, are due at 5:00 PM on the Friday of the week they are assigned.

Exercise 1

Whereami? Print your working directory to the screen

## One line of code here:
getwd()
## [1] "C:/Users/becamach/OneDrive - North Carolina State University/Documents/DSA595/1"

Exercise 2

Use R as a simple calculator to type in 3 or 4 mathematical operations and print to screen

## Example ## 
2+2
## [1] 4
## Your mathematical commands here
2-1
## [1] 1
3-2
## [1] 1
4-3
## [1] 1

Exercise 3

  • Using the rnorm() function create:
    • an object named x with 100 values drawn from a random normal distribution
    • use the plot() function to plot x and change points to solid and color to red and title the plot, “100 values drawn from a random normal distribution”
      • Hint: ?plot.default will help
    • use the boxplot() function to plot x and change color
## Your code here
rnorm(100)
##   [1]  0.430738547  0.460776077  1.456082610  0.343076945 -0.670456504
##   [6] -0.818092749 -1.084459555  0.744349420  1.516161917 -0.039247152
##  [11]  0.021904154  0.073366473 -1.086852629  1.092775920  0.991422334
##  [16] -0.459911317 -1.096716788  0.651742700 -0.431409530  1.423526334
##  [21] -0.840078883  0.828143428 -0.281383711  1.912248786 -0.193891433
##  [26]  0.194682910  0.490873853 -1.501149192  0.145351908 -0.083294606
##  [31] -0.703410170  0.409220778  0.470836260  1.509841292 -0.509028093
##  [36] -0.747763531  0.987717528  1.592291330  0.564064916 -0.147385588
##  [41] -0.063352974 -1.462386125  0.260251499  0.926496891  1.695760365
##  [46]  1.533862308  0.604777707  1.148937016 -2.153685351  0.189543762
##  [51] -0.631703710 -1.745120676 -1.743003876  1.121635720 -1.610091807
##  [56] -0.462948921  0.344443445 -0.009992215  1.005231934 -0.593001677
##  [61] -0.311869639  0.234199804  0.753151512 -0.450398413  1.055566672
##  [66]  0.729623570 -2.113133238 -1.120317132 -1.408008359 -0.082920817
##  [71] -1.223718811  0.027011435  1.365650576 -2.121525101  0.976989469
##  [76]  1.226896164  0.438364714  0.727322861 -1.109628263  1.047949925
##  [81] -2.010517461  1.258946612 -0.476076731 -0.477591101  0.184323870
##  [86] -1.481039431  1.143937431  0.549077514 -1.136356125  0.039424853
##  [91] -0.654251079 -1.110931663  0.996765055  0.339018514  0.682409348
##  [96] -0.336832698  0.318969258  0.311816702 -1.746584632  0.915916483
x <- rnorm(100)
plot(x, pch = 19, main= '100 values drawn from a random normal distribution', col="red") 

boxplot(x, col = "deeppink")

Exercise 4

I’ve downloaded and unzipped a dataset with summary level information from the GTEx portal. https://gtexportal.org/home/downloads/adult-gtex/bulk_tissue_expression

  • Ask R to print the names of the dataset with the names() function
  • Ask R to print the first 6 records of the dataset with the head() function
## Read in the file 
## I've provided this for you - Do not change the next line
gtex_summary_data <- read.delim2("GTEx_Analysis_2017-06-05_v8_RNASeQCv1.1.9_gene_median_tpm.gct", skip = 2) 

## Convert expression data columns to numeric 
## I've provided this for you - Do not change the next line
gtex_summary_data[3:56] <- lapply(gtex_summary_data[3:56], as.numeric)

## Round Data to 3 decimal places for ease of printing 
## I've provided this for you - Do not change the next line
gtex_summary_data[3:56] <- lapply(gtex_summary_data[3:56], function(x) round(x,3))

##  Ask R for column names of the gtex_summary_data dataset 
# Your code here
colnames(gtex_summary_data, prefix = "col")
##  [1] "Name"                                     
##  [2] "Description"                              
##  [3] "Adipose...Subcutaneous"                   
##  [4] "Adipose...Visceral..Omentum."             
##  [5] "Adrenal.Gland"                            
##  [6] "Artery...Aorta"                           
##  [7] "Artery...Coronary"                        
##  [8] "Artery...Tibial"                          
##  [9] "Bladder"                                  
## [10] "Brain...Amygdala"                         
## [11] "Brain...Anterior.cingulate.cortex..BA24." 
## [12] "Brain...Caudate..basal.ganglia."          
## [13] "Brain...Cerebellar.Hemisphere"            
## [14] "Brain...Cerebellum"                       
## [15] "Brain...Cortex"                           
## [16] "Brain...Frontal.Cortex..BA9."             
## [17] "Brain...Hippocampus"                      
## [18] "Brain...Hypothalamus"                     
## [19] "Brain...Nucleus.accumbens..basal.ganglia."
## [20] "Brain...Putamen..basal.ganglia."          
## [21] "Brain...Spinal.cord..cervical.c.1."       
## [22] "Brain...Substantia.nigra"                 
## [23] "Breast...Mammary.Tissue"                  
## [24] "Cells...Cultured.fibroblasts"             
## [25] "Cells...EBV.transformed.lymphocytes"      
## [26] "Cervix...Ectocervix"                      
## [27] "Cervix...Endocervix"                      
## [28] "Colon...Sigmoid"                          
## [29] "Colon...Transverse"                       
## [30] "Esophagus...Gastroesophageal.Junction"    
## [31] "Esophagus...Mucosa"                       
## [32] "Esophagus...Muscularis"                   
## [33] "Fallopian.Tube"                           
## [34] "Heart...Atrial.Appendage"                 
## [35] "Heart...Left.Ventricle"                   
## [36] "Kidney...Cortex"                          
## [37] "Kidney...Medulla"                         
## [38] "Liver"                                    
## [39] "Lung"                                     
## [40] "Minor.Salivary.Gland"                     
## [41] "Muscle...Skeletal"                        
## [42] "Nerve...Tibial"                           
## [43] "Ovary"                                    
## [44] "Pancreas"                                 
## [45] "Pituitary"                                
## [46] "Prostate"                                 
## [47] "Skin...Not.Sun.Exposed..Suprapubic."      
## [48] "Skin...Sun.Exposed..Lower.leg."           
## [49] "Small.Intestine...Terminal.Ileum"         
## [50] "Spleen"                                   
## [51] "Stomach"                                  
## [52] "Testis"                                   
## [53] "Thyroid"                                  
## [54] "Uterus"                                   
## [55] "Vagina"                                   
## [56] "Whole.Blood"
##  Ask R for first 6 records of the gtex_summary_data dataset
# Your code here
head(gtex_summary_data, n=6)
##                Name Description Adipose...Subcutaneous
## 1 ENSG00000223972.5     DDX11L1                  0.000
## 2 ENSG00000227232.5      WASH7P                  4.064
## 3 ENSG00000278267.1   MIR6859-1                  0.000
## 4 ENSG00000243485.5 MIR1302-2HG                  0.000
## 5 ENSG00000237613.2     FAM138A                  0.000
## 6 ENSG00000268020.3      OR4G4P                  0.000
##   Adipose...Visceral..Omentum. Adrenal.Gland Artery...Aorta Artery...Coronary
## 1                        0.000         0.000          0.000             0.000
## 2                        3.371         2.685          4.048             3.901
## 3                        0.000         0.000          0.000             0.000
## 4                        0.000         0.000          0.000             0.000
## 5                        0.000         0.000          0.000             0.000
## 6                        0.000         0.036          0.000             0.000
##   Artery...Tibial Bladder Brain...Amygdala
## 1            0.00   0.000            0.000
## 2            3.64   5.164            1.439
## 3            0.00   0.000            0.000
## 4            0.00   0.000            0.000
## 5            0.00   0.000            0.000
## 6            0.00   0.035            0.050
##   Brain...Anterior.cingulate.cortex..BA24. Brain...Caudate..basal.ganglia.
## 1                                    0.000                           0.000
## 2                                    1.693                           1.566
## 3                                    0.000                           0.000
## 4                                    0.000                           0.024
## 5                                    0.000                           0.000
## 6                                    0.054                           0.046
##   Brain...Cerebellar.Hemisphere Brain...Cerebellum Brain...Cortex
## 1                         0.000              0.000          0.000
## 2                         4.992              5.721          2.483
## 3                         0.000              0.000          0.000
## 4                         0.000              0.000          0.027
## 5                         0.000              0.000          0.000
## 6                         0.025              0.037          0.043
##   Brain...Frontal.Cortex..BA9. Brain...Hippocampus Brain...Hypothalamus
## 1                        0.000               0.000                0.000
## 2                        2.147               1.686                1.748
## 3                        0.000               0.000                0.000
## 4                        0.030               0.000                0.025
## 5                        0.000               0.000                0.000
## 6                        0.042               0.053                0.040
##   Brain...Nucleus.accumbens..basal.ganglia. Brain...Putamen..basal.ganglia.
## 1                                     0.000                           0.000
## 2                                     1.539                           1.442
## 3                                     0.000                           0.000
## 4                                     0.031                           0.023
## 5                                     0.000                           0.000
## 6                                     0.045                           0.048
##   Brain...Spinal.cord..cervical.c.1. Brain...Substantia.nigra
## 1                              0.000                    0.000
## 2                              2.730                    1.742
## 3                              0.000                    0.000
## 4                              0.000                    0.020
## 5                              0.000                    0.000
## 6                              0.042                    0.047
##   Breast...Mammary.Tissue Cells...Cultured.fibroblasts
## 1                   0.000                        0.000
## 2                   4.439                        1.679
## 3                   0.000                        0.000
## 4                   0.000                        0.000
## 5                   0.000                        0.000
## 6                   0.030                        0.000
##   Cells...EBV.transformed.lymphocytes Cervix...Ectocervix Cervix...Endocervix
## 1                               0.000               0.000               0.000
## 2                               2.495               5.629               7.097
## 3                               0.000               0.000               0.000
## 4                               0.000               0.000               0.000
## 5                               0.000               0.000               0.000
## 6                               0.000               0.000               0.024
##   Colon...Sigmoid Colon...Transverse Esophagus...Gastroesophageal.Junction
## 1           0.000              0.000                                 0.000
## 2           4.648              3.595                                 4.326
## 3           0.000              0.000                                 0.000
## 4           0.000              0.000                                 0.000
## 5           0.000              0.000                                 0.000
## 6           0.015              0.033                                 0.036
##   Esophagus...Mucosa Esophagus...Muscularis Fallopian.Tube
## 1              0.000                  0.000          0.000
## 2              3.117                  4.103          6.134
## 3              0.000                  0.000          0.000
## 4              0.000                  0.000          0.000
## 5              0.000                  0.000          0.000
## 6              0.000                  0.000          0.000
##   Heart...Atrial.Appendage Heart...Left.Ventricle Kidney...Cortex
## 1                    0.000                  0.000           0.000
## 2                    1.520                  0.925           2.771
## 3                    0.000                  0.000           0.000
## 4                    0.000                  0.018           0.018
## 5                    0.000                  0.000           0.000
## 6                    0.036                  0.051           0.039
##   Kidney...Medulla Liver  Lung Minor.Salivary.Gland Muscle...Skeletal
## 1            0.000 0.000 0.000                0.000             0.000
## 2            2.215 1.765 4.508                3.528             1.417
## 3            0.000 0.000 0.000                0.000             0.000
## 4            0.000 0.000 0.000                0.000             0.000
## 5            0.000 0.000 0.000                0.000             0.000
## 6            0.000 0.033 0.000                0.000             0.038
##   Nerve...Tibial Ovary Pancreas Pituitary Prostate
## 1          0.000 0.000    0.000     0.000    0.000
## 2          6.685 6.634    1.809     5.425    7.083
## 3          0.000 0.000    0.000     0.000    0.000
## 4          0.000 0.000    0.000     0.000    0.000
## 5          0.000 0.000    0.000     0.000    0.000
## 6          0.000 0.000    0.000     0.000    0.021
##   Skin...Not.Sun.Exposed..Suprapubic. Skin...Sun.Exposed..Lower.leg.
## 1                               0.000                          0.000
## 2                               5.933                          6.133
## 3                               0.000                          0.000
## 4                               0.000                          0.000
## 5                               0.000                          0.000
## 6                               0.027                          0.000
##   Small.Intestine...Terminal.Ileum Spleen Stomach Testis Thyroid Uterus Vagina
## 1                            0.000  0.000   0.000  0.166   0.000   0.00  0.000
## 2                            4.194  5.926   3.062  4.703   6.273   7.19  5.746
## 3                            0.000  0.000   0.000  0.000   0.000   0.00  0.000
## 4                            0.000  0.000   0.000  0.054   0.000   0.00  0.000
## 5                            0.000  0.000   0.000  0.000   0.000   0.00  0.000
## 6                            0.035  0.000   0.033  0.000   0.000   0.00  0.000
##   Whole.Blood
## 1       0.000
## 2       2.647
## 3       0.000
## 4       0.000
## 5       0.000
## 6       0.000

Exercise 5

NOTE, this question has multiple parts - read carefully

We can subset a column from the dataset with the $
  • Plot the expression values of liver vs. lung with plot() with red circles
  • Plot another plot with same two columns, but this time transform the data on the log scale
    • example - if x is a column of the dataset, then log2(x+1) will add 1 to every value and take the log2 of it
  • Make sure to title your plots - type ?base::plot at the console if you need to see the options for plot
## Your code here 
plot(x= gtex_summary_data$Liver,y= gtex_summary_data$Lung, col = "red", xlab = "Liver", ylab = "Lung", main = "Liver vs Lung plot")

plot(x= gtex_summary_data$Liver,y= gtex_summary_data$Lung, log = "xy", xlab = "Log Liver", ylab = "Log Lung", main = "Log plot Liver vs Lung")
## Warning in xy.coords(x, y, xlabel, ylabel, log): 29640 x values <= 0 omitted
## from logarithmic plot
## Warning in xy.coords(x, y, xlabel, ylabel, log): 26151 y values <= 0 omitted
## from logarithmic plot