Python Running cumulative sum with a given window

Question

What I want to do is generate a numpy array that is the cumulative sum of another numpy array given a certain window.

For example, given an array [1,2,3,4,5,6

Answer 1

seberg's answer is better and more general than mine, but note that you need to zero-pad your samples to get the result you want.

import numpy as np
from numpy.lib.stride_tricks import as_strided as ast
samples = 100
window = 3
padding = np.zeros(window - 1)
# zero-pad your samples
a = np.concatenate([padding,np.arange(1,samples + 1)])
newshape = (len(a) - window,window)
newstrides = a.strides * 2
# this gets you a sliding window of size 3, with a step of 1
strided = ast(a,shape = newshape,strides = newstrides)
# get your moving sum
strided.sum(1)