[Numpy-discussion] masked arrays as array indices (is a bad idea)
Mon Sep 21 15:35:58 CDT 2009
On Sep 21, 2009, at 4:23 PM, Ernest Adrogué wrote:
> This explains why x[x == 3] = 4 works "as expected", whereas
> x[x == 0] = 4 ruins everything. Basically, any condition that matches
> 0 will match every masked item as well.
There's room for improvement here indeed. I need to check first
whether fixing the comparison methods doesn't break anything.
> I don't know, but maybe it would be better to raise an exception when
> the index is a masked array then. The current behaviour seems a bit
> confusing to me.
That'd be modifying ndarray.__getitem__ and I don't see that
happening. In the meantime, please just fill your masked array with
the `filled` method or the corresponding function.
Remmber that masked arrays are for convenience. As soon as you try to
do some heavy computations, you're better processing data and mask
More information about the NumPy-Discussion