如何使用两个不同的 arrays 处理不同的索引

Question

I have two arrays y=[0,1,1], x=[0,0,4,10,5] and a Index-array with integers that has the indices of the non-zero entrys from x I_x=[2,3,4] .

And idealy I would want something like y[2]=0, y[3]=1, y[4]=1

Is there any way to do that for the general case.

I'm happy to answer further questions because I don't think this question is asked well enough.

edit:

def function(x,y):
    solution = 0
    for i in I:
        solution = x[i] + y[i]
    return solution

This is an example what I want to do, the problem is i is from I so y would be out of bounds, what I want to know is there any way to solve this problem.

Answer 1

Your question is still a bit unclear, but I think you are trying to produce an array which contains the sum of the nonzero elements in x with the elements in y in those positions, and you are trying to adjust it so that I _x will not be out of bounds for y . The script below does just that:

import numpy as np

def uneven_add(a, b):
    return a[np.nonzero(a)] + np.hstack((b, np.zeros((a.size - b.size))))[np.nonzero(a)]

if __name__ == '__main__':
    x = np.array([0,0,4,10,5])
    y = np.array([0,1,1])
    print(uneven_add(x,y))