# scipy.ndimage.sum_labels¶

scipy.ndimage.sum_labels(input, labels=None, index=None)[source]

Calculate the sum of the values of the array.

Parameters
inputarray_like

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

labelsarray_like of ints, optional

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

indexarray_like, optional

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

Returns
sumndarray 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.

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


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