Section One

Creating a list with multiple built-in data sets. Below is accessing the Species variable from the iris data within the list.

l1 <- list(df1 = mtcars, df2 = iris, df3 = USArrests) #a list of 3 built in data sets

l1$df2$Species #way 1 to access Species from the list
##   [1] setosa     setosa     setosa     setosa     setosa     setosa    
##   [7] setosa     setosa     setosa     setosa     setosa     setosa    
##  [13] setosa     setosa     setosa     setosa     setosa     setosa    
##  [19] setosa     setosa     setosa     setosa     setosa     setosa    
##  [25] setosa     setosa     setosa     setosa     setosa     setosa    
##  [31] setosa     setosa     setosa     setosa     setosa     setosa    
##  [37] setosa     setosa     setosa     setosa     setosa     setosa    
##  [43] setosa     setosa     setosa     setosa     setosa     setosa    
##  [49] setosa     setosa     versicolor versicolor versicolor versicolor
##  [55] versicolor versicolor versicolor versicolor versicolor versicolor
##  [61] versicolor versicolor versicolor versicolor versicolor versicolor
##  [67] versicolor versicolor versicolor versicolor versicolor versicolor
##  [73] versicolor versicolor versicolor versicolor versicolor versicolor
##  [79] versicolor versicolor versicolor versicolor versicolor versicolor
##  [85] versicolor versicolor versicolor versicolor versicolor versicolor
##  [91] versicolor versicolor versicolor versicolor versicolor versicolor
##  [97] versicolor versicolor versicolor versicolor virginica  virginica 
## [103] virginica  virginica  virginica  virginica  virginica  virginica 
## [109] virginica  virginica  virginica  virginica  virginica  virginica 
## [115] virginica  virginica  virginica  virginica  virginica  virginica 
## [121] virginica  virginica  virginica  virginica  virginica  virginica 
## [127] virginica  virginica  virginica  virginica  virginica  virginica 
## [133] virginica  virginica  virginica  virginica  virginica  virginica 
## [139] virginica  virginica  virginica  virginica  virginica  virginica 
## [145] virginica  virginica  virginica  virginica  virginica  virginica 
## Levels: setosa versicolor virginica

Below is another way of accessing the Species variable from the iris data within the list.

l1[[2]][,5] #way 2 to access Species from the list
##   [1] setosa     setosa     setosa     setosa     setosa     setosa    
##   [7] setosa     setosa     setosa     setosa     setosa     setosa    
##  [13] setosa     setosa     setosa     setosa     setosa     setosa    
##  [19] setosa     setosa     setosa     setosa     setosa     setosa    
##  [25] setosa     setosa     setosa     setosa     setosa     setosa    
##  [31] setosa     setosa     setosa     setosa     setosa     setosa    
##  [37] setosa     setosa     setosa     setosa     setosa     setosa    
##  [43] setosa     setosa     setosa     setosa     setosa     setosa    
##  [49] setosa     setosa     versicolor versicolor versicolor versicolor
##  [55] versicolor versicolor versicolor versicolor versicolor versicolor
##  [61] versicolor versicolor versicolor versicolor versicolor versicolor
##  [67] versicolor versicolor versicolor versicolor versicolor versicolor
##  [73] versicolor versicolor versicolor versicolor versicolor versicolor
##  [79] versicolor versicolor versicolor versicolor versicolor versicolor
##  [85] versicolor versicolor versicolor versicolor versicolor versicolor
##  [91] versicolor versicolor versicolor versicolor versicolor versicolor
##  [97] versicolor versicolor versicolor versicolor virginica  virginica 
## [103] virginica  virginica  virginica  virginica  virginica  virginica 
## [109] virginica  virginica  virginica  virginica  virginica  virginica 
## [115] virginica  virginica  virginica  virginica  virginica  virginica 
## [121] virginica  virginica  virginica  virginica  virginica  virginica 
## [127] virginica  virginica  virginica  virginica  virginica  virginica 
## [133] virginica  virginica  virginica  virginica  virginica  virginica 
## [139] virginica  virginica  virginica  virginica  virginica  virginica 
## [145] virginica  virginica  virginica  virginica  virginica  virginica 
## Levels: setosa versicolor virginica

Section Two

qplot is a function built into the ggplot2 package. qplot stands for quick plot and it allows you to plot data sets quickly. You are able to create labels, titles, facet the data, and more.

Below is a scatter plot for Sepal.Length vs Sepal.Width based on the iris data frame.

qplot(Sepal.Width, Sepal.Length, data=iris, xlab = "Sepal Width", ylab = "Sepal Length", main = "Sepal Length vs Sepal Width")+
  theme(plot.title = element_text(hjust = 0.5))

Below is a scatter plot for Sepal.Length vs Sepal.Width based on the iris data frame with Species colored.

qplot(Sepal.Width, Sepal.Length, data=iris, xlab = "Sepal Width", ylab = "Sepal Length", main = "Sepal Length vs Sepal Width", colour = Species)+
  theme(plot.title = element_text(hjust = 0.5))

Below is a scatter plot for disp vs. mpg based on the iris data frame and the points colored are am (transmission - automatic or manual.

mtcars$am = factor(mtcars$am) #create am as a factor (0 or 1)

qplot(mpg, disp, data=mtcars, xlab = "Miles/(US) gallon",ylab = "Displacement (cu.in.)", main = "Displacement vs. Miles Per Gallon", color = am)+
  theme(plot.title = element_text(hjust = 0.5))+
  scale_color_manual(values = c("red", "forestgreen"),labels = c("Automatic","Manual"))+
  labs(col="Transmission (am)")