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

[Doug H. <dh...@uc...>]

Maurice:  Actually, I meant how does one draw a color key on a plot? 
(See the attached graphic).  I can now generate this plot using my
nascent 
PDL interface to PLplot.  The trick that initially stymied me involved
resetting the viewport and window on the same subpage.

I also have a perl module that uses PLplot to interface to the GMT map
database to draw coastlines and political boundaries.

I'll release these to CPAN soon.

Regards, 

  Doug Hunt


Maurice LeBrun wrote:
> 
> 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...

-- 
dh...@uc...
Software Engineer III, Sometimes Sysadmin
UCAR - COSMIC, Tel. (303) 497-2611