Re: [Plplot-general] color key on shade plots

[Maurice L. <mj...@ga...>]

Doug Hunt writes:
 > Hi all:  Is there any provision in PLplot for generating a color key to
 > associate values with colors in cmap1?  This would be the equivalent of
 > the pgwedge command in PGPLOT.

A value <-> color association in PLplot is called a control point.  Between
these the HLS values are linearly interpolated according to position (value).
So the minimum number of control points is two, at the cmap1 boundaries, but
by increasing the number of control points (through the API, or you can edit a
palette file and load it with the Tk interface) you can get a variety of
effects.  E.g. in the last release I increased the number of control points in
the default map from 4 to 6 to better show off weaker features than the
previous palette.  The maximum number of control points is 256, which should
be far more than anyone really needs.

-- 
Maurice LeBrun    mj...@ga...