Re: palette plus extra color?

[Allin C. <cot...@wf...>]

On Sat, 13 Jun 2020, Ethan Merritt wrote:

> On Saturday, 13 June 2020 12:07:02 PDT Ethan A Merritt wrote:
>> 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:*]
>
> Ah, sorry. I missed the normal color for ( >= 0) requirement.
>         set cbrange [-0.001:*]

Thanks, Ethan. I'd actually tried "set palette defined" plus "set 
cbrange" but I failed to get it right.

Allin