#817 palette documentation

[Adam Majewski]

Hi
I have created a extended documentation about gnuplot palette ( color gradient):
https://pl.wikibooks.org/wiki/Gnuplot#Gradient_koloru

It is in polish now, but it can be easly translated to english ( draft version by Google tranlate)

What do you think about it ?
What do you think about expanding "help set palette" ?

Adam
https://gitlab.com/adammajewski/color_gradient
https://commons.wikimedia.org/w/index.php?title=Special:ListFiles/Adam_majewski&ilshowall=1

[Ethan Merritt]

I would be happy to add a link https://pl.wikibooks.org/wiki/Gnuplot on the gnuplot home page section "Localized learning pages".

I can only judge the content via Google translate. It looks fine overall. I have one suggestion: since the section on gamma correction immediately follows the section on the cubehelix palette, you could mention or even show an example that the cubehelix palette can be modified by gamma. E.g.

     set palette cubehelix gamma 2.0

Is there a particular block of text you want to add to the "help" section?

You may be interested to know there is a development branch that adds a new set of palette coloring features. The active palette can be saved to a colormap array with the command

     set palette save <colormap-name>

You can define and save multiple palettes this way. Subsequent plots can be colored by referring to a saved palette by name. Here is an example:

set palette defined (0 "dark-red", 1 "white")
set palette save reds
set palette defined(0  "greenyellow", 1 "dark-green")
set palette save greens
splot func1(x,y) with pm3d fc palette reds, func2(x,y) with pm3d fc palettes greens

I expect to merge this into the main develoment branch soon.

[Adam Majewski]

Hi,

Thx for the answer
Is it possible to add example files: .pal , .map and *.gpf
to the gnuplot code ?
Then it would possible to make live/easy examples

I would like to add section abot text file ( sorr not fully translated)
https://en.wikibooks.org/wiki/Gnuplot/palette#Text_file
and defined
https://en.wikibooks.org/wiki/Gnuplot/palette#defined

Highlight the difference ( in the file ) between using:
load
set palette file

Thx

Adam

[Ethan Merritt]

Your expertise probably is greater than mine. I do not recognize those file types and I do not understand CIE colorspace well enough to add an example or to document it. Perhaps you could contribute a demo file that shows how to trace a palette through this space? We could include it in the demo collection and refer to it in the documentation.

As to "set palette file", there is already a documentation section with examples. How is "load" relevant here? Any command that you can type interactively could also be executed by loading it from a script file. "set palette" commands are no different from any other command in this regard.

I added a link to the wikibooks page on the gnuplot web site.

[Adam Majewski]

I have made demos fore reading gradient from the file

[Adam Majewski]

I have made hsv profile using finction from the gnuplot :
see also
https://gitlab.com/adammajewski/color_gradient#rainbow-colormap-or-sawtooth-rainbow-or-hsv

[Adam Majewski]

c and gnuplot files

[Adam Majewski]

https://commons.wikimedia.org/wiki/File:0_3d_60_75_v.png

[Ethan Merritt]

Ticket moved from /p/gnuplot/support-requests/246/