scipy.ndimage.sum

scipy.ndimage.sum(input, labels=None, index=None)

Calculate the sum of the values of the array.

Parameters:

input : array_like

Values of input inside the regions defined by labels are summed together.

labels : array_like of ints, optional

Assign labels to the values of the array. Has to have the same shape as input.

index : array_like, optional

A single label number or a sequence of label numbers of the objects to be measured.

Returns:

sum : ndarray or scalar

An array of the sums of values of input inside the regions defined by labels with the same shape as index. If ‘index’ is None or scalar, a scalar is returned.

See also

mean, median

Examples

>>> from scipy import ndimage
>>> input =  [0,1,2,3]
>>> labels = [1,1,2,2]
>>> ndimage.sum(input, labels, index=[1,2])
[1.0, 5.0]
>>> ndimage.sum(input, labels, index=1)
1
>>> ndimage.sum(input, labels)
6