遍历数组numpy的的第一个D轴 [英] Iterating over first d axes of numpy array

问题描述

我给斧头任意数量的数组，我想遍历，说他们的第一个D。我该怎么做呢？

I'm given an array with an arbitrary number of axes, and I want to iterate over, say the first 'd' of them. How do I do this?

起初我以为我会做一个包含所有我想要循环指数通过一个数组，使用

Initially I thought I would make an array containing all the indices I want to loop through, using

i = np.indices(a.shape[:d])
indices = np.transpose(np.asarray([x.flatten() for x in i]))
for idx in indices:
    a[idx]

但显然我不能像索引一个数组，即使用包含索引另一个数组。

But apparently I cannot index an array like that, i.e. using another array containing the index.

推荐答案

您可以使用的 ndindex ：

You can use ndindex:

d = 2
a = np.random.random((2,3,4))
for i in np.ndindex(a.shape[:d]):
    print i, a[i]

输出：

(0, 0) [ 0.72730488  0.2349532   0.36569509  0.31244037]
(0, 1) [ 0.41738425  0.95999499  0.63935274  0.9403284 ]
(0, 2) [ 0.90690468  0.03741634  0.33483221  0.61093582]
(1, 0) [ 0.06716122  0.52632369  0.34441657  0.80678942]
(1, 1) [ 0.8612884   0.22792671  0.15628046  0.63269415]
(1, 2) [ 0.17770685  0.47955698  0.69038541  0.04838387]

这篇关于遍历数组numpy的的第一个D轴的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！