Re: [matplotlib-devel] Better defaults all around?

[Todd <tod...@gm...>]

On Sat, Nov 22, 2014 at 12:22 AM, Nathaniel Smith <nj...@po...> wrote:

> - Default line colors: The rgbcmyk color cycle for line plots doesn't
> appear to be based on any real theory about visualization -- it's just
> the corners of the RGB color cube, which is a highly perceptually
> non-uniform space. The resulting lines aren't terribly high contrast
> against the default white background, and the different colors have
> varying luminance that makes some lines "pop out" more than others.
>
> Seaborn's default is to use a nice isoluminant variant on matplotlib's
> default:
>
> http://web.stanford.edu/~mwaskom/software/seaborn/tutorial/aesthetics.html
> ggplot2 uses isoluminant colors with maximally-separated hues, which
> also works well. E.g.:
>
> http://www.cookbook-r.com/Graphs/Colors_%28ggplot2%29/ggplot2_scale_hue_colors_l45.png
>
>

About this, I am not expert so forgive me if this is nonsensical.  However,
it would seem to me that these requirements are basically the same as the
requirements for the new default colormap that prompted this whole
discussion.  So, rather than create two inconsistent set of colors that
accomplish similar goals, might it be better to instead use the default
colormap for the line colors?  You could pick "N" equally-spaced colors
from the colormap and use those as the line colors.

You could even take this a step further, and instead of hard-coding the
line colors, you could make it possible to assign a named colormap to the
line colors parameter.  Then there could be a second integer parameter that
determines how many colors to pick from that colormap (it would only do
anything if the line colors are a colormap, otherwise it would be
ignored).