Re: palette plus extra color?

[Ethan A M. <me...@uw...>]

On Saturday, 13 June 2020 11:25:46 PDT Allin Cottrell wrote:
> The following doesn't work (not surprising) but I'm wondering if 
> there's any real gnuplot syntax that'll do what it's trying to do:
> 
> plot for [i=0:*] 'polygons.dat' index i with filledcurves \
>   fc ($3 < 0 ? 'gray' : palette)
> 
> The datafile contains several datasets representing polygons; the 
> first 2 columns hold the coordinates of vertices and the third a 
> value to be colorized (if >= 0) or shown as missing (gray) if 
> negative.

Define the palette such that cb=0 is gray, the rest whatever you want.

     set palette defined (-0.001 "gray",   0 "first palette color", ..., 1 "last palette color")
     set cbrange [0:*]
 

	Ethan