# scipy.sparse.spmatrix.sum¶

spmatrix.sum(self, axis=None, dtype=None, out=None)[source]

Sum the matrix elements over a given axis.

Parameters
axis{-2, -1, 0, 1, None} optional

Axis along which the sum is computed. The default is to compute the sum of all the matrix elements, returning a scalar (i.e., axis = None).

dtypedtype, optional

The type of the returned matrix and of the accumulator in which the elements are summed. The dtype of a is used by default unless a has an integer dtype of less precision than the default platform integer. In that case, if a is signed then the platform integer is used while if a is unsigned then an unsigned integer of the same precision as the platform integer is used.

New in version 0.18.0.

outnp.matrix, optional

Alternative output matrix in which to place the result. It must have the same shape as the expected output, but the type of the output values will be cast if necessary.

New in version 0.18.0.

Returns
sum_along_axisnp.matrix

A matrix with the same shape as self, with the specified axis removed.

numpy.matrix.sum