Display a barplot with a gap (missing range) on one axis

Displays a barplot with a missing range.

Usage

gap_barp(height,gap,width=0.4,names.arg=names(height),
 col=NULL,main="",xlab="",ylab="",xlim=NULL,ylim=NULL,x=NULL,
 height.at=pretty(height),height.lab=NULL,...)

Arguments

height: a vector of data values
gap: the range of values to be left out
width: the proportion of bar width to bar spacing divided by 2. width=1 means no spaces between the bars.
names.arg: labels for the bars.
col: color(s) in which to plot the values
main: title for the plot.
xlab: label for the x axis
ylab: label for the y axis
xlim: Optional x limits for the plot
ylim: optional y limits for the plot
x: optional x positions for the bars.
height.at: explicit positions for the y axis ticks
height.lab: explicit labels for the y axis ticks.
...: arguments passed to barp.

Value

The center positions of the bars.

Details

Displays a barplot omitting a range of values on the X or Y axis. Typically used when there is a relatively large gap in the range of values represented as bar heights. See axis.break for a brief discussion of plotting on discontinuous coordinates.

If the user does not ask for specific y limits, the function will calculate limits based on the range of the data values. If passing specific limits, remember to subtract the gap from the upper or lower limit.

Author

Jim Lemon

Examples

 oneout<-c(rnorm(5,sd=5),20,rnorm(5,sd=5))
 gap_barp(oneout,gap=c(8,16),xlab="Index",height.at=c(-5,0,5,20),
  ylab="Group values",main="Barplot with gap above zero")

 oneout[6]<--20
 gap_barp(oneout,gap=c(-8,-16),xlab="Index",height.at=c(-20,-5,0,5),
  ylab="Group values",main="Barplot with gap below zero")