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

[Charles R Harris]

On Thu, Jun 23, 2011 at 3:44 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.
>
>
So we are looking for unhappy users ;) Making the functionality, whatever it
turns out to be, faster, more complete, and easier to use also seems a
worthy goal.

Chuck
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