python - How to get the cumulative sum of numpy array in-place -

i want compute integral image. example

a=array([(1,2,3),(4,5,6)]) b = a.cumsum(axis=0) 

this generate array b.can execute cumsum in-place. if not . there other methods that

you have pass argument out:

np.cumsum(a, axis=1, out=a) 

obs: array 2-d array, can use axis=0 sum along rows , axis=1 sum along columns.