Place labels in boxes

Places labels in boxes on an existing plot

Usage

boxed.labels(x,y=NULL,labels,
  bg=ifelse(match(par("bg"),"transparent",0),"white",par("bg")),
  border=TRUE,xpad=1.2,ypad=1.2,srt=0,cex=1,adj=0.5,xlog=FALSE,ylog=FALSE,...)

Arguments

x,y: x and y position of the centers of the labels. x can be an xy.coords list.
bg: The fill color of the rectangles on which the labels are displayed (see Details).
labels: Text strings
border: Whether to draw borders around the rectangles.
xpad,ypad: The proportion of the rectangles to the extent of the text within.
srt: Rotation of the labels. If 90 or 270 degrees, the box will be rotated 90 degrees.
cex: Character expansion. See text.
adj: left/right adjustment. If this is set outside the function, the box will not be aligned properly.
xlog: Whether the X axis is a log axis
ylog: Whether the Y axis is a log axis
...: additional arguments passed to text.

Details

The label(s) are displayed on a rectangular background. This may be useful for visibility and is the reason that "transparent" background is not available. With the default textcol=NA, the function tries to work out whether white or black text will be more easily read based on the background color and displays the text accordingly. If the user specifies text colors in the additional arguments, these colors will override the automatic white/black above - see the last example.

Only right angle rotations are allowed in boxed.labels. Important change: xpad and ypad are now the full proportion of the box to text, not half. The user can now call cylindrect or gradient.rect for the background rectangle.

Note

This function is best for regularly spaced labels where overlapping is not a problem. See thigmophobe.labels for placing labels where overlap is likely.

Value

nil

Author

Jim Lemon - thanks to Thorn Thaler for the code allowing user-specified text colors and Flemming Skjoth for the log axis correction

Examples

 x<-rnorm(10)
 y<-rnorm(10)
 plot(x,y,type="p")
 nums<-c("one","two","three","four","five","six","seven","eight","nine","ten")
 boxed.labels(x,y-0.1,nums)

 # now label a barplot
 xpos<-barp(c(1,3,2,4))
 boxed.labels(xpos$x,0.5,nums[1:4])
 # and add labels below the x axis ticks
 boxed.labels(xpos$x,-0.4,c("First","Second","Third","Fourth"))

 # perform a PCA on the "swiss" dataset and plot the first two components
 data(swiss)
 swiss.pca<-prcomp(swiss)
 plot(swiss.pca$rotation[,1:2],xlim=c(-1,0.2),main="PCA of swiss dataset",
  type="n")
 boxed.labels(swiss.pca$rotation[1:6],swiss.pca$rotation[7:12],ypad=1.5,
  colnames(swiss),bg=c("red","purple","blue","blue","darkgreen","red"),
  col="yellow")