[Numpy-discussion] in the NA discussion, what can we agree on?

Benjamin Root ben.root@ou....
Thu Nov 3 22:20:14 CDT 2011


On Thursday, November 3, 2011, Gary Strangman <strang@nmr.mgh.harvard.edu>
wrote:
>
> For the non-destructive+propagating case, do I understand correctly that
> this would mean I (as a user) could temporarily decide to IGNORE certain
> portions of my data, perform a series of computation on that data, and the
> IGNORED flag (or however it is implemented) would be propagated from
> computation to computation? If that's the case, I suspect I'd use it all
> the time ... to effectively perform data subsetting without generating
> (partial) copies of large datasets. But maybe I misunderstand the
> intended notion of propagation ...
>
> Gary
>

Propagating is default NaN-like behavior when performing a sum with at
least one NaN in it. Ignoring is like using nansum on that same array.

Masking, one can think of it as very fancy indexing, but the shape and
structure of the data is maintained.

Ben Root
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