Increment Numpy array with repeated indices

Question

I have a Numpy array and a list of indices whose values I would like to increment by one. This list may contain repeated indices, and I would like the increment to scale wit

Answer 1

If b is a small subrange of a, one can refine Alok's answer like this:

import numpy as np
a = np.zeros( 100000, int )
b = np.array( [99999, 99997, 99999] )

blo, bhi = b.min(), b.max()
bbins = np.bincount( b - blo )
a[blo:bhi+1] += bbins

print a[blo:bhi+1]  # 1 0 2