You can position the key legend manually in most plotting programs. For example, in gnuplot it's done using set key top right. In ggplot2, it's done like this.
Is there a plotting library, script, or simple algorithm that automatically positions the legend such that it overlaps the data in the plot minimally?
What I mean is: Suppose I plot the line y=x. A good place for the legend in that case would be top left or bottom right.
Try this,
require(Hmisc)
?largest.empty
there are other discussions and functions proposed in R-help archives
require(plotrix)
?emptyspace # Find the largest empty space on a plot
This is the example from the help page:
x<-rnorm(100)
y<-rnorm(100)
plot(x,y,main="Find the empty space",xlab="X",ylab="Y")
es<-plotrix::emptyspace(x,y)
# use a transparent background so that any overplotted points are shown
plotrix::boxed.labels(es,labels="Here is the\nempty space",bg="transparent")
