DOC: ndimage convolve origin documentation (#14745)

[alexandschaefer]

gh-14745

Reference issue

What does this implement/fix?

Fixes incorrect assignment of left and right in current documentation.

Additional information

[rgommers]

Thanks @alexandschaefer. This fixes the obvious bug in the description. Did you consider adopting the proposed more extensive description from gh-14745? The ascii visualization used there seems nice. It'll render fine in html if you use reST markup like this I expect (double colon plus blank lines around the content to be typeset):

    Visualizations with an input of length 5 and a filter of length 3::

         origin of 0     origin of -1     origin of 1
         -----           -----            -----
        ---            ---                ---

[alexandschaefer]

Thanks @alexandschaefer. This fixes the obvious bug in the description. Did you consider adopting the proposed more extensive description from gh-14745? The ascii visualization used there seems nice. It'll render fine in html if you use reST markup like this I expect (double colon plus blank lines around the content to be typeset):

    Visualizations with an input of length 5 and a filter of length 3::

         origin of 0     origin of -1     origin of 1
         -----           -----            -----
        ---            ---                ---

Hi @rgommers. Thank you for approving.

To your question. I considered but did not like visualization: I do not think it is very obvious what input and output is (to someone who needs to read it). Also it seems that the output is shifted by ~3 whitespaces.

[rgommers]

Okay, thanks for considering it. In it goes then.