On Wed, Nov 26, 2014 at 9:30 AM, Todd <tod...@gm...> wrote: > 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. The main differences in requirements are: - for the color cycle, you want isoluminant colors, to avoid the issue where one line is glaring bright red and one is barely-visible-grey. For general-purpose 2d colormaps, though, you almost always want the luminance to vary to help distinguish colors from each other. - for the color cycle, there's no problem with using widely separated hues -- in fact it's usually better b/c it increases contrast between the different items, and there's no need to communicate an ordering between them. But if you try to use the whole hue space in a colormap then you end up with the much-loathed jet. -n -- Nathaniel J. Smith Postdoctoral researcher - Informatics - University of Edinburgh http://vorpus.org
