在一个数组中连接多个 numpy 数组? [英] concatenate multiple numpy arrays in one array?

问题描述

假设我有很多 numpy 数组:

a = ([1,2,3,4,5])b = ([2,3,4,5,6])c = ([3,4,5,6,7])

我想生成一个新的二维数组:

d = ([[1,2,3,4,5],[2,3,4,5,6],[3,4,5,6,7]])

我应该编码什么?我试过用过:

d = np.concatenate((a,b),axis=0)d = np.concatenate((d,c),axis=0)

它返回:

d = ([1,2,3,4,5,2,3,4,5,6,3,4,5,6,7])

解决方案

正如评论中提到的，你可以使用 np.array 函数:

<预><代码>>>>将 numpy 导入为 np>>>a = ([1,2,3,4,5])>>>b = ([2,3,4,5,6])>>>c = ([3,4,5,6,7])>>>np.array([a, b, c])数组([[1, 2, 3, 4, 5],[2, 3, 4, 5, 6],[3, 4, 5, 6, 7]])

一般情况下，您希望基于not-yet-existing"维度进行堆叠，您也可以使用 np.stack:

<预><代码>>>>np.stack([a, b, c],axis=0)数组([[1, 2, 3, 4, 5],[2, 3, 4, 5, 6],[3, 4, 5, 6, 7]])>>>np.stack([a, b, c], axis=1) # 不是你想要的，这只是为了展示什么是可能的数组([[1, 2, 3],[2, 3, 4],[3, 4, 5],[4, 5, 6],[5, 6, 7]])

Assume I have many numpy array:

a = ([1,2,3,4,5])
b = ([2,3,4,5,6])
c = ([3,4,5,6,7])

and I want to generate a new 2-D array:

d = ([[1,2,3,4,5],[2,3,4,5,6],[3,4,5,6,7]])

What should I code? I tried used:

d = np.concatenate((a,b),axis=0)
d = np.concatenate((d,c),axis=0)

It returns:

d = ([1,2,3,4,5,2,3,4,5,6,3,4,5,6,7])

解决方案

As mentioned in the comments you could just use the np.array function:

>>> import numpy as np
>>> a = ([1,2,3,4,5])
>>> b = ([2,3,4,5,6])
>>> c = ([3,4,5,6,7])

>>> np.array([a, b, c])
array([[1, 2, 3, 4, 5],
       [2, 3, 4, 5, 6],
       [3, 4, 5, 6, 7]])

In the general case that you want to stack based on a "not-yet-existing" dimension, you can also use np.stack:

>>> np.stack([a, b, c], axis=0)
array([[1, 2, 3, 4, 5],
       [2, 3, 4, 5, 6],
       [3, 4, 5, 6, 7]])

>>> np.stack([a, b, c], axis=1)  # not what you want, this is only to show what is possible
array([[1, 2, 3],
       [2, 3, 4],
       [3, 4, 5],
       [4, 5, 6],
       [5, 6, 7]])

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