[Numpy-discussion] maskedarray: how to force mask to expand
Vincent Schut
schut at sarvision.nl
Wed Sep 24 06:25:57 EDT 2008
Probably I'm just overlooking something obvious, but I'm having problems
with maskedarrays (numpy.ma from svn: '1.3.0.dev5861'), the mask by
default being a single bool value ('False') instead of a properly sized
bool array. If I then try to mask one value by assigning values to
certain mask positions (a.mask[0,0]=True) I get an error, logically. I
know I can use mask_where, but I like the mask[...] idiom. And I have to
expand the mask anyway, as I'm gonna write it to a file at the end.
1) Is there a way to have ma always use properly expanded masks (bool
arrays instead of single bool values)? I tried the shrink=False keyword,
but that does not do what I want, and is not available for
numpy.ma.zeros, which I conveniently use a lot.
2) Is there a method/function to request the mask, be it a single bool
value or an array, as a properly sized array? I found shrink_mask but no
opposite method, and shrink_mask seems to do something subtly different
even.
Regards,
Vincent.
More information about the NumPy-Discussion
mailing list