[NumPy-Tickets] [NumPy] #1666: Reducing the memory usage of MaskedArrays after DomainedBinaryOperation

[NumPy Trac]

#1666: Reducing the memory usage of MaskedArrays after DomainedBinaryOperation
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 Reporter:  lee                |       Owner:  pierregm   
     Type:  enhancement        |      Status:  new        
 Priority:  normal             |   Milestone:  Unscheduled
Component:  numpy.ma           |     Version:  1.5.0      
 Keywords:  mask memory usage  |  
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 I noticed that when I create a new masked array with no mask (yet) I am
 given a mask=False. After dividing this mask by a nonzero number, the mask
 becomes the same shape as the array, populated entirely with 'False'. I
 would like to not increase my memory usage unnecessarily after safe
 operations.

 I attempted to patch the ma/core.py file to check the mask: If all entries
 are False, the mask is not applied to the result. The patch works for
 divide, but not for mod (%). It doesn't seem like mod passes through
 _DomainedBinaryOperation.__call__ even though it is decorated as such in
 ma/core.py .

 Is there another location that overrides this mod operation that I
 can/should patch? Is this patch even useful or a good idea?

 - Chris

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Ticket URL: <http://projects.scipy.org/numpy/ticket/1666>
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