[Numpy-discussion] feedback request: proposal to add masks to the core ndarray

[Matthew Brett]

Hi,

On Thu, Jun 23, 2011 at 10:44 PM, Robert Kern <robert.kern at gmail.com> wrote:
> On Thu, Jun 23, 2011 at 15:53, Mark Wiebe <mwwiebe at gmail.com> wrote:
>> Enthought has asked me to look into the "missing data" problem and how NumPy
>> could treat it better. I've considered the different ideas of adding dtype
>> variants with a special signal value and masked arrays, and concluded that
>> adding masks to the core ndarray appears is the best way to deal with the
>> problem in general.
>> I've written a NEP that proposes a particular design, viewable here:
>> https://github.com/m-paradox/numpy/blob/cmaskedarray/doc/neps/c-masked-array.rst
>> There are some questions at the bottom of the NEP which definitely need
>> discussion to find the best design choices. Please read, and let me know of
>> all the errors and gaps you find in the document.
>
> One thing that could use more explanation is how your proposal
> improves on the status quo, i.e. numpy.ma. As far as I can see, you
> are mostly just shuffling around the functionality that already
> exists. There has been a continual desire for something like R's NA
> values by people who are very familiar with both R and numpy's masked
> arrays. Both have their uses, and as Nathaniel points out, R's
> approach seems to be very well-liked by a lot of users. In essence,
> *that's* the "missing data problem" that you were charged with: making
> happy the users who are currently dissatisfied with masked arrays. It
> doesn't seem to me that moving the functionality from numpy.ma to
> numpy.ndarray resolves any of their issues.

Maybe it would help if you could say specifically which issues you
think are not being addressed?  Or was this more in the way of a
'please speak up'?

Cheers,

Matthew