[Matplotlib-users] getting extra colors in figure
efiring at hawaii.edu
Tue Jul 26 13:47:11 EDT 2016
On 2016/07/22 8:24 AM, Smit, Christine E. (GSFC-610.2)[TELOPHASE CORP]
> Hi! I’m trying to plot data using imshow and ending up with more colors
> than I specify in the colormap. This is causing problems with a downstream
> user who is machine reading images to determine approximate data values
> based on colors. I think the issue has something to do with rounding
> because many colors in the image are only slightly off from the colors I
> specified. My plots have exactly one pixel per data value, so each pixel¹s
> color should be exactly a color in the colormap.
To solve the problem, try using interpolation = 'nearest' rather than
'none'. The distinction between these is two is endlessly confusing,
is an attempt to illustrate it.
In your example, with "nearest" I get 5 unique colors, not 6.
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