[Numpy-discussion] how to name "contagious" keyword in np.ma.convolve

[Allan Haldane]

On 10/14/2016 07:49 PM, Juan Nunez-Iglesias wrote:
> +1 for propagate_mask. That is the only proposal that immediately makes
> sense to me. "contagious" may be cute but I think approximately 0% of
> users would guess its purpose on first use.
>
> Can you elaborate on what happens with the masks exactly? I didn't quite
> get why propagate_mask=False was unintuitive. My expectation is that any
> mask present in the input will not be set in the output, but the mask
> will be "respected" by the function.

Here's an illustration of how the PR currently works with convolve, 
using the name "propagate_mask":

     >>> m = np.ma.masked
     >>> a = np.ma.array([1,1,1,m,1,1,1,m,m,m,1,1,1])
     >>> b = np.ma.array([1,1,1])
     >>>
     >>> print np.ma.convolve(a, b, propagate_mask=True)
     [1 2 3 -- -- -- 3 -- -- -- -- -- 3 2 1]
     >>> print np.ma.convolve(a, b, propagate_mask=False)
     [1 2 3 2 2 2 3 2 1 -- 1 2 3 2 1]

Allan


> On 15 Oct. 2016, 5:23 AM +1100, Allan Haldane <allanhaldane at gmail.com>,
> wrote:
>> I think the possibilities that have been mentioned so far (here or in
>> the PR) are:
>>
>> contagious
>> contagious_mask
>> propagate
>> propagate_mask
>> propagated
>>
>> `propogate_mask=False` seemed to imply that the mask would never be set,
>> so Eric also suggested
>> propagate_mask='any' or propagate_mask='all'
>>
>>
>> I would be happy with 'propagated=False' as the name/default. As Eric
>> pointed out, most MaskedArray functions like sum implicitly don't
>> propagate, currently, so maybe we should do likewise here.
>>
>>
>> Allan