STAT 451, Day 15

More Tools to Visualize Data

Return to setup variables for example

# ggplot2 examples
library(ggplot2) 

# create factors with value labels 
mtcars$gear <- factor(mtcars$gear,levels=c(3,4,5),
    labels=c("3gears","4gears","5gears")) 
mtcars$am <- factor(mtcars$am,levels=c(0,1),
    labels=c("Automatic","Manual")) 
mtcars$cyl <- factor(mtcars$cyl,levels=c(4,6,8),
    labels=c("4cyl","6cyl","8cyl"))

More R Code

# Scatterplot of mpg vs. hp for each 
# combination of gears and cylinders
# in each facet, transmition type is 
# represented by shape and color
qplot(hp, mpg, data=mtcars, shape=am, 
   color=am, facets=gear~cyl, size=I(3),
   xlab="Horsepower", ylab="Miles per 
   Gallon")

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More R Code

# Separate smoothers of mpg on weight for each number of cylinders
qplot(wt, mpg, data=mtcars, geom=c("point", 
   "smooth"), color=cyl, 
   main="Smoothers of MPG on Weight", 
   xlab="Weight", ylab="Miles per Gallon")

plot of chunk unnamed-chunk-3

More R Code

# Boxplots of mpg by number of gears 
# observations (points) are overlayed and jittered
qplot(gear, mpg, data=mtcars, 
   geom=c("boxplot", "jitter"), 
   fill=gear, main="Mileage by Gear Number",
   xlab="", ylab="Miles per Gallon")

plot of chunk unnamed-chunk-4