A data visualization example from A LAYERED GRAMMAR OF GRAPHICS
Load package ggplot2
library(ggplot2)
Read datasets
troops <- read.table("https://github.com/XUKEREN/KERENXU/files/1866822/minard-troops.txt", header=T)
cities <- read.table("https://github.com/XUKEREN/KERENXU/files/1866821/minard-cities.txt", header=T)
Set the object size as the number of survivors
plot_troops <- ggplot(troops, aes(long, lat)) +
geom_path(aes(size = survivors, colour = direction, group = group))
plot_troops
Add the cities on the plot according to their coordinates
plot_both <- plot_troops +
geom_text(aes(label = city), size = 4, data = cities)
plot_both
plot_polished <- plot_both +
scale_size(range = c(1, 12),
breaks = c(1, 2, 3) * 10^5, labels =(c(1, 2, 3) * 10^5)) +
scale_colour_manual(values = c("grey50","red")) +
xlab(NULL) +
ylab(NULL)
plot_polished
Save plots in pdf
ggsave(plot_troops, file = "minard-troops.pdf", width=12, height=3)
ggsave(plot_both, file = "minard-both.pdf", width=12, height=3)
ggsave(plot_polished, file = "minard-polished.pdf", width=12, height=3)
Another example from the ‘A layered Grammar of Graphics’
library(ggplot2)
continuous variable mapped to size and colour, discrete variable mapped to shape and colour.
Examples of axes and grid lines for three coordinate systems:
Cartesian, semi-log and polar. The polar coordinate system
illustrates the difficulties associated with non-Cartesian
x1 <- c(1,10)
y1 <- c(1, 5)
p <- qplot(x1, y1, geom="blank", xlab=NULL, ylab=NULL) + theme_bw()
p
p + coord_trans(y="log10")
p + coord_polar()
A bullseye chart is the polar equivalent of the spineplot: in the pie chart, categories have equal radius and variable angle; in the radial chart, categories have equal angle and variable radius.
bars <- qplot(clarity, data=diamonds, geom="blank", fill=clarity) +
scale_fill_brewer(palette="YlGnBu")
stack <- bars + aes(x = factor(1)) + scale_x_discrete(labels = "")
stack + geom_bar(width = 1) + coord_polar(theta="y")
stack + geom_bar(width = 1) + coord_polar()
The Coxcomb plot is a bar chart in polar coordinates.
bars + geom_bar()
bars + geom_bar(width = 1) + coord_polar()
