numpy.ma.masked_array.sum

method

masked_array.sum(self, axis=None, dtype=None, out=None, keepdims=<no value>)

Return the sum of the array elements over the given axis.

Masked elements are set to 0 internally.

Refer to numpy.sum for full documentation.

See also

ndarray.sum

corresponding function for ndarrays

numpy.sum

equivalent function

Examples

>>> x = np.ma.array([[1,2,3],[4,5,6],[7,8,9]], mask=[0] + [1,0]*4)
>>> print(x)
[[1 -- 3]
 [-- 5 --]
 [7 -- 9]]
>>> print(x.sum())
25
>>> print(x.sum(axis=1))
[4 5 16]
>>> print(x.sum(axis=0))
[8 5 12]
>>> print(type(x.sum(axis=0, dtype=np.int64)[0]))
<type 'numpy.int64'>