from statmethods.net
# ggplot2 examples
library(ggplot2)
# use color brewer as default discrete colors
scale_colour_discrete <- function(...) scale_color_brewer(palette = "Set1",
...)
scale_fill_discrete <- function(...) scale_fill_brewer(palette = "Set1", ...)
data("mtcars")
# 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"))
head(mtcars)
## mpg cyl disp hp drat wt qsec vs am gear
## Mazda RX4 21.0 6cyl 160 110 3.90 2.620 16.46 0 Manual 4gears
## Mazda RX4 Wag 21.0 6cyl 160 110 3.90 2.875 17.02 0 Manual 4gears
## Datsun 710 22.8 4cyl 108 93 3.85 2.320 18.61 1 Manual 4gears
## Hornet 4 Drive 21.4 6cyl 258 110 3.08 3.215 19.44 1 Automatic 3gears
## Hornet Sportabout 18.7 8cyl 360 175 3.15 3.440 17.02 0 Automatic 3gears
## Valiant 18.1 6cyl 225 105 2.76 3.460 20.22 1 Automatic 3gears
## carb
## Mazda RX4 4
## Mazda RX4 Wag 4
## Datsun 710 1
## Hornet 4 Drive 1
## Hornet Sportabout 2
## Valiant 1
grouped by number of gears (indicated by color)
qplot(mpg, data = mtcars, geom = "density", fill = gear, alpha = I(0.5), main = "Distribution of Gas Milage",
xlab = "Miles Per Gallon", ylab = "Density")
for each combination of gears and cylinders in each facet, transmission 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")
Separate for each number of cylinders
qplot(wt, mpg, data = mtcars, geom = c("point", "smooth"), method = "lm", formula = y ~
x, color = cyl, main = "Regression of MPG on Weight", xlab = "Weight", ylab = "Miles per Gallon")
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")
Author: Jim Hester Created: 2013 Mar 20 10:57:07 AM Last Modified: 2013 Aug 22 02:59:42 PM