Add a simple legend in form of a color bar to a plot.
Usage
doLegend(breaks, col, side)
Arguments
breaks
a vector of breaks defining a set of intervals for the data
col
a vector of colors corresponding to the intervals.
side
integer between 1 and 4, indicating on which side of the main plot the legend is supposed to be drawn. Standard interpretation: 1 = below, continuing clock-wise.
This is an extremely simple way of giving a visual impression of what numerical values correspond to a given color. The actual plot is done via a call to image and axis.