Feature request: logarithmic (continuous) color scale

[simleb]

A logarithmic continuous color scale would be nice to have.

Consistently with Scale.x_continuous and Scale.y_continuous, a number of transformed continuous scales could be provided:

• Scale.color_continuous (scale without any transformation).
• Scale.color_log10
• Scale.color_log2
• Scale.color_log
• Scale.color_asinh
• Scale.color_sqrt

[durcan]

I brought up some trouble I was having implementing exactly this functionality in #573. I agree that colors currently are in need of some attention, both in scalings as well as optional, built-in colormaps.

[tbreloff]

It doesn't directly solve your request, but here's how you could customize using Plots.jl:

julia> using Plots, RDatasets; gadfly();

julia> d = dataset("ggplot2", "diamonds");

julia> hexbin(d, :Price, :Carat,
              nbins=70,
              size=(500,500),
              c=colorscheme(:heat, [0,0.01,1]),
              bg=:black)

julia> png("/home/tom/tmp")

One caveat is that you'll need to do a Pkg.checkout("Plots") for it to work properly, as I've recently fixed a bug.