如何在numpy中执行此数组索引

时间:2012-01-10 18:36:01

标签: python arrays numpy

给定索引数组I,如何设置D中索引不存在的数据数组I的值?

示例:如何从AI获取D

I = array( [[1,1], [2,2], [3,3]] )

D = array( [[ 1, 2, 3, 4, 5, 6],
            [ 7, 8, 9, 1, 2, 3],
            [ 4, 5, 6, 7, 8, 9],
            [ 1, 2, 3, 4, 5, 6],
            [ 7, 8, 9, 1, 2, 3]] )

A = array( [[ 0, 0, 0, 0, 0, 0],
            [ 0, 8, 0, 0, 0, 0],
            [ 0, 0, 6, 0, 0, 0],
            [ 0, 0, 0, 4, 0, 0],
            [ 0, 0, 0, 0, 0, 0]] )

编辑:我正在寻找如何在Id很大的情况下一次性完成此操作。

1 个答案:

答案 0 :(得分:10)

简单的解决方案:

A = zeros(D.shape)
for i, j in I:
    A[i, j] = D[i, j]

矢量化:

A = zeros(D.shape)
i, j = I.T
A[i, j] = D[i, j]