[Numpy-discussion] Clarifications in numpy.ma module

Benjamin Root ben.root at ou.edu
Tue Dec 30 17:56:16 EST 2014

exception? Did you mean warning? If warning, I recall some discussion
recently to figure out a way to hide that, but only for masked values (I
would want to see the warning if I do bad calculations in the unmasked
portions of my array).

Now I see your point 3 much more clearly. I had never noticed that the
divide could produce new masked elements. It is presumptuous to assume that
NaNs are what I want masked. Division (and exponential) are the only two
binary operations I can imagine where two valid floats could produce a NaN
or Inf, so that is probably why the division was different from the others.
This confusion probably came about in conflating valid-ness with NaN and
Inf as concepts. In small parts of the codebase, it seems to operate with
the concept that NaN === invalid, while other parts strictly works within
the framework of masked === invalid.

Of course, fixing any of this would be potentially a significant change in
behavior. I am certainly not one to make any sort of determination on this.
I am just a heavy user of masked arrays.

Ben Root

On Tue, Dec 30, 2014 at 5:37 PM, Maniteja Nandana <
maniteja.modesty067 at gmail.com> wrote:

> I was just referring to the exception raised in the case where the length
> of the array is zero. I have not thought if the example provided by
> @Alexander.
> I was also wondering if the automatic masking of NaN should be done or
> not, which is why I asked about the difference in the operating named
> arrays upon division, where they are automatically masked and
> multiplication, where they aren't.( point 3)
> Cheers,
> N.Maniteja
> _______________________________________________
> NumPy-Discussion mailing list
> NumPy-Discussion at scipy.org
> http:// <http://mail.scipy.org/mailman/listinfo/numpy-discussion>
> mail.scipy.org <http://mail.scipy.org/mailman/listinfo/numpy-discussion>
> /mailman/ <http://mail.scipy.org/mailman/listinfo/numpy-discussion>
> listinfo <http://mail.scipy.org/mailman/listinfo/numpy-discussion>/
> <http://mail.scipy.org/mailman/listinfo/numpy-discussion>numpy-discussion
> <http://mail.scipy.org/mailman/listinfo/numpy-discussion>
> _______________________________________________
> NumPy-Discussion mailing list
> NumPy-Discussion at scipy.org
> http://mail.scipy.org/mailman/listinfo/numpy-discussion
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/numpy-discussion/attachments/20141230/cff7ba84/attachment.html>

More information about the NumPy-Discussion mailing list