python - 如何将向量的每个元素提升为另一个向量的每个元素的幂？

Question

我想通过从 0 到 5 的递增幂来提高向量:

import numpy as np

a = np.array([1, 2, 3]) # list of 11 components
b = np.array([0, 1, 2, 3, 4]) # power
c = np.power(a,b)

期望的结果是:

c = [[1**0, 1**1, 1**2, 1**3, 1**4], [2**0, 2**1, ...], ...]

我不断收到此错误:

ValueError: operands could not be broadcast together with shapes (3,) (5,)

Answer 1

一种解决方案是为数组添加一个新维度 a

c = a[:,None]**b

# Using broadcasting : 
# (3,1)**(4,) --> (3,4)
#
#     [[1],
# c =  [2], ** [0,1,2,3,4]
#      [3]]

有关更多信息，请查看 numpy broadcasting documentation