如何在python中删除数组的所有其他元素? (np.repeat()的反函数?) [英] How to remove every other element of an array in python? (The inverse of np.repeat()?)

问题描述

如果我有一个数组x，并执行np.repeat(x,2)，则实际上是在复制该数组.

If I have an array x, and do an np.repeat(x,2), I'm practically duplicating the array.

>>> x = np.array([1,2,3,4])    
>>> np.repeat(x, 2)
array([1, 1, 2, 2, 3, 3, 4, 4])

我该如何做相反的事情，以便最终得到原始数组?

How can I do the opposite so that I end up with the original array?

它也应该与随机数组y一起工作:

It should also work with a random array y:

>>> y = np.array([1,7,9,2,2,8,5,3,4])  

如何删除其他所有元素，以便得到以下内容?

How can I delete every other element so that I end up with the following?

array([7, 2, 8, 3])

推荐答案

y[1::2]应该可以完成这项工作.在这里，第二个元素通过用1进行索引选择，然后以2的间隔取值.

y[1::2] should do the job. Here the second element is chosen by indexing with 1, and then taken at an interval of 2.

这篇关于如何在python中删除数组的所有其他元素? (np.repeat()的反函数?)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！