Feature request: Resample Gradient

[alex-s-gardner]

It would be nice to have a function within ColorSchemes to convert between a Gradient.

To Gradient a ColorSchemes gradient you need a function from another package: either 'PlotUtils.palette' or 'Makie.resample_cmap'

It seems that such a basic functionality should live within ColorSchemes

[cormullion]

Hi! What exactly do those functions (PlotUtils.palette Makie.resample_cmap) do?

[alex-s-gardner]

They simply discretize a color gradient with a requested number of samplings .

I often find myself wanting to create a new color palette of n colors from a gradient. Does that make sense?

[alex-s-gardner]

For example:

the desired function f could create :acton10:

acton10 = f(:acton, 10)

but also any other integer number of samples

[cormullion]

This is sort of built in:

using ColorSchemes

acton10 = ColorScheme(
    get(ColorSchemes.acton, 0.0:0.1:1.0))

get allows various kinds of sampling; the ColorScheme constructor converts the vector of colors to a ColorScheme.

[alex-s-gardner]

Ah man... I wish I had found get a long time ago.. didn't think of using ranges. I wonder if it's worth including this example under basic usage

I do think a helper function would still be welcome:

function resample(colorscheme, n)

  newscheme = ColorScheme(
      get(ColorSchemes[colorscheme], (0:n)/n))

end

[cormullion]

I think it would be a good idea to add more information to the docstrings and documentation, particularly if it's not that easy to find at the moment. Perhaps using words like "resample" might help discoverability....

[cormullion]

I added some more words to the documentation.

[alex-s-gardner]

Looks good, thanks. Would you be oppose to adding a resample function? For people that are newer to the language:

get(ColorSchemes.darkrainbow, range(0.0, 1.0, length=20)) |> ColorScheme

can be a bit intimidating to resample a colormap. I think a resample function is simple, robust and intuitive. I'd be happy to make a PR.