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

Calculate the sum of the values of the array.

labels : array of integers, same shape as input

Assign labels to the values of the array.

index : scalar or array

A single label number or a sequence of label numbers of the objects to be measured. If index is None, all values are used where ‘labels’ is larger than zero.


>>> input =  [0,1,2,3]
>>> labels = [1,1,2,2]
>>> sum(input, labels, index=[1,2])
[1.0, 5.0]