mx.nd.sum.axis

Description

Computes the sum of array elements over given axes.

Note

sum and sum_axis are equivalent. For ndarray of csr storage type summation along axis 0 and axis 1 is supported. Setting keepdims or exclude to True will cause a fallback to dense operator.

Example:

data = [[[1, 2], [2, 3], [1, 3]],
[[1, 4], [4, 3], [5, 2]],
[[7, 1], [7, 2], [7, 3]]]

sum(data, axis=1)
[[  4.   8.]
[ 10.   9.]
[ 21.   6.]]

sum(data, axis=[1,2])
[ 12.  19.  27.]

data = [[1, 2, 0],
[3, 0, 1],
[4, 1, 0]]

csr = cast_storage(data, 'csr')

sum(csr, axis=0)
[ 8.  3.  1.]

sum(csr, axis=1)
[ 3.  4.  5.]

Arguments

Argument

Description

data

NDArray-or-Symbol.

The input

axis

Shape or None, optional, default=None.

The axis or axes along which to perform the reduction.

The default, axis=(), will compute over all elements into a scalar array with shape (1,).

If axis is int, a reduction is performed on a particular axis.

If axis is a tuple of ints, a reduction is performed on all the axes specified in the tuple.

If exclude is true, reduction will be performed on the axes that are NOT in axis instead.

Negative values means indexing from right to left.

keepdims

boolean, optional, default=0.

If this is set to True, the reduced axes are left in the result as dimension with size one.

exclude

boolean, optional, default=0.

Whether to perform reduction on axis that are NOT in axis instead.