Take the 2-minute tour ×
Cross Validated is a question and answer site for people interested in statistics, machine learning, data analysis, data mining, and data visualization. It's 100% free, no registration required.

I have a good feel for the types of data that go with most colormaps. But I don't know what kind of data one would want to use the following types of colormaps:


Flag in <code>matplotlib</code>


Prism in <code>matplotlib</code>

Source: http://dept.astro.lsa.umich.edu/~msshin/science/code/matplotlib_cm/

I can't see any use for them except as a fill pattern.

What kinds of data benefit from these types of colormaps? And does this type of map have a specific name?

share|improve this question
I suspect they are available for decorative rather than data presentation purposes. It's worth noting that they are each actually a more straightforward pattern repeated ten times. So the only situation where it would be useful would be one where you want to represent the remainder once you have lopped off the first significant digit. This might be necessary sometimes but not very often I would have thought. –  Peter Ellis Jan 14 '13 at 20:13
@PeterEllis Decoration was my thought too, but many visualization packages include maps like this (not just matplotlib) so I was wondering if anybody out there knew of any non-decorative uses. –  tpg2114 Jan 14 '13 at 20:38
I've never heard justification for mapping the same color to multiple values. An example, and further chastising for it, can be found in this blog post by Robert Kosara. At least that is an example use, although Kosara says no justification is given for it. –  Andy W Jan 14 '13 at 20:40
I have seen such color schemes used when particular thresholds need visual emphasis: a sharp break in the color graduation at the threshold(s) becomes manifest as an apparent contour in the plot itself. –  whuber Jan 14 '13 at 20:49

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.