Jul 282011
 

Plot legend outside of the plot area

primitive method:

method1, hard code layout (
https://stat.ethz.ch/pipermail/r-help/2007-May/132466.html)

layout(matrix(c(2,1), byrow = T), height=c(2,10))
par(mar=c(5,3,0,2))
plot(rnorm(100))
grid(10,10)
plot.new()
par(mar=c(0,0,0,0))
plot.window(c(0,1), c(0,1))
lsize = legend(0.5, .5, "text", pch=’o’)
box("figure")
box(, lty = 2)
box("plot", col = "red")
points(rnorm(100), type="n")
# layout.show(2) : display the layout

method 2, refer to:

use xpd = NA options will not clip the legend outside of the plot area, however, you need to manual place the legend, that makes plot less pleasant. However, the folloing example works:

data(iris)
par(xpd = NA, mai=rep(.5,4), mfrow=c(2,2))
for(i in 1:4)
boxplot(iris[,i]~iris[,5], main=colnames(iris)[i], col=2:4, xaxt="n")
 
width <- 6 # width of the plot device in inches (it should be 7 inches by
# default but Windows does not implement this correctly)
leg <- legend(0, 0, legend=levels(iris$Species), fill=2:4, hor=TRUE, plot=FALSE)
xcoord <- grconvertX(width/2, "inches", "user")-leg$rect$w/2
ycoord <- grconvertY(0, "inches", "user")+leg$rect$h
 
legend(xcoord, ycoord, legend=levels(iris$Species), fill=2:4, bty="n", hor=TRUE)

package ggplot2:

Example:

> ggplot(dat,aes(x=x)) +
+ geom_histogram(aes(y=..density..,fill="Histogram"),binwidth=0.5) +
+ stat_function(fun = dnorm, aes(colour= "Density")) +
+ scale_x_continuous(‘x’, limits = c(-4, 4)) +
+ opts(title = "Histogram with Overlay") +
+ scale_fill_manual(name="",value="blue") +
+ scale_colour_manual(name="",value="red") +
+ scale_y_continuous(‘Frequency’)+
+ opts(legend.key=theme_rect(fill="white",colour="white"))+
+ opts(legend.background = theme_blank())

package Lattice:

Specify space = "bottom", or space = "right" in the auto.keys or key parameter

Example:

> xyplot( lat ~ long , data = quakes, key = list( points = list( col=c("orange","white","blue")), text = list( c("a","b","c") ), space="bottom"))
> xyplot( lat ~ long , data = quakes, key = list( points = list( col=c("orange","white","blue")), text = list( c("a","b","c") ), space="right"))
> barchart(yield ~ variety | site, data = barley,
groups = year, layout = c(1,6), stack = TRUE,
auto.key = list(space = "right"),
ylab = "Barley Yield (bushels/acre)",
scales = list(x = list(rot = 45)))

https://stat.ethz.ch/pipermail/r-help/2005-July/075953.html

Powered by Qumana