[Matplotlib-users] HiLo colormap

Thomas Caswell tcaswell at gmail.com
Mon Jun 4 21:53:30 EDT 2018

I would not call it hacky, this is exactly what the over/under
functionality is for!  It also fits the use-case of the blog post where
there is some knowledge that 0 and the max-int are invalid.

You are going to have a related  issue with the color map.  It is going to
take the top/bottom 1/Nth of the range to be marked as over/under which may
be _more_ that you want to grab.  I also think it will grab asymmetrical
ranges for log scales.

For the API I am thinking something like

`im = ax.imshow(..., over_color='r', under_color='b')`

so that you can control that aspect of the color map from the user API.


On Mon, Jun 4, 2018 at 8:19 PM Juan Nunez-Iglesias <jni.soma at gmail.com>

> On Tue, Jun 5, 2018, at 10:37 AM, Thomas Caswell wrote:
> Given that you can already do that with the over/under values I suspect we
> just need better documentation of this feature.
> I would argue that over/under is hacky for this use-case, given that the
> vmin and vmax have to be set not to the data but to something slightly less
> than the data. For int as in the SO answer, it was relatively
> straightforward. For float data now you have to set it to 0+epsilon,
> 1-epsilon, which isn't fun.
> Extending the colormappable family of things to take over/under/bad colors
> as input might also be a nice convince to add.
> Can you elaborate on the interface you are envisioning for this?
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