Re: [matplotlib-devel] [Patch] NonUniformImage uses np.asarray; should use ma.asarray

[Klaus Z. <kla...@fm...>]

Eric Firing schrieb:
> John Hunter wrote:
>> On Mon, Jul 21, 2008 at 3:12 AM, Klaus Zimmermann
>> <kla...@fm...> wrote:
>>> Hello *,
>>>
>>> right now the NonUniformImage class in image.py uses numpy's asarray
>>> method. All similar classes instead use numpy.ma.asarray, thus allowing
>>> for masked images.
[...]
> Masked arrays are handled automatically as needed by the 
> ScalarMappable.to_rgba() method.
> 
> What we really wanted, and the change I made throughout image.py, is to 
> keep masked input as masked, and to ensure that anything else is a plain 
> ndarray.  This is now committed.
I just checked and I think your changes solve my problem well, obviously 
without introducing the potential problems you mentioned above. Thanks!
I was just confused by the different semantics:
AxesImage : does masks, NxM array expects N, M dimensions.
NonUniformImage : didn't do masks, NxM array expects N, M dimensions.
PcolorImage: does masks, NxM array expects N+1, M+1 dimensions.

Though I think the mask thingie in the NonUniformImage was simply a bug 
and I understand why PcolorImage is the way it is, it still stumped me 
at first sight. Also I find it difficult to understand the difference 
Pcolor and NonUniform since NonUniform does pseudo colors just as well?
However if you feel this is just a lack of RTFM on my part please feel 
free to ignore.

> I considered using np.asanyarray(A) but rejected it because it could 
> fail for matrix input if any code is expecting iteration or 
> single-indexing to return a 1-D array.
Makes sense. But perhaps we should refactor that check into a (module) 
function of its own, as to avoid recundancy? I can do that if you want, 
or if you prefer a classmethod in AxesImage?


> We lack examples to test masking of various types of input in the 
> various types of image, though.  Maybe I will add that later.  Klaus, if 
> you have any nice, small examples you would like to add to the mpl 
> examples directory, that illustrate features or use cases that are not 
> exercised in any present examples, please submit them.
Will do.

Cheers,
Klaus