... and for dessert, is there a circular colormap that would work for
the colorblind?
Almost certainly not, at least not without compromising other desirable features for circular colormaps. You could do a circle roughly perpendicular to the lines of confusion, but this would mean going up and down in lightness, which perceptually overemphasizes the light half.
On the other hand, this may not be a bad thing if 0 degrees and/or 180 degrees are special as might be the case with phase measurements and other complex number-related things.
My department is practicing presenting-science-for-the-general-public,
and the problems 'heat maps' have for the colorblind keep coming up.
As a deuteronopic, I heartily thank you for paying attention to these issues.
I've written an application to visualize colormaps in 3D perceptual space as well as simulating colorblindness. It uses Mayavi and Chaco, so you will need a full Enthought Tool Suite installation:
http://www.enthought.com/~rkern/cgi-bin/hgwebdir.cgi/colormap_explorer/
Of interest for this thread might be the function find_chroma() in hcl_opt.py which will, given a lightness value in HCL space, find the largest chroma value (roughly similar to saturation) such that a circle at the given lightness value will just fit inside of the RGB gamut. A simple maximization on that function will find the lightness that gives the largest chroma and hence the largest dynamic range of such a colormap. However, it should be noted that I have found such colormaps to appear a little washed out and drab. But then, I'm colorblind.
···
On 2009-11-09 11:46 AM, Chloe Lewis wrote:
--
Robert Kern
"I have come to believe that the whole world is an enigma, a harmless enigma
that is made terrible by our own mad attempt to interpret it as though it had
an underlying truth."
-- Umberto Eco