Re: [Matplotlib-users] specifying NaN color when using imshow

[John H. <jdh...@ac...>]

>>>>> "Gerald" == Gerald John M Manipon <Ger...@jp...> writes:

    Gerald> Hello, I'm trying to plot some grid data using basemap and
    Gerald> imshow however haven't figured out how to specify the
    Gerald> color for nan values.  For example, in my data, valid
    Gerald> values range from 0.0-10.0.  I've assigned -9999.0 and
    Gerald> 1e30 to the missing values and when I imshow (setting
    Gerald> vmin=0.0, vmax=10.0), the missing values show up in the
    Gerald> low and high end of the spectrum, respectively.  Is there
    Gerald> a way to do this?

See the archives for a post by Danny Shevitz and followups in the
thread "obscure colormapping issue related to quantization"

http://article.gmane.org/gmane.comp.python.matplotlib.general/2856/match=obscure+colormapping+issue+related+to+quantization

Basically, you want to write a custom normalization and colormapping
instance, and recipe code is posted in the thread linked above.

JDH