有没有办法使用" out"在适当修改数组时Numpy函数的参数?

时间:2016-01-12 21:46:54

标签: python arrays numpy

如果我想获得两个数组的点积,我可以通过指定一个存储输出的数组而不是创建一个新数组来获得性能提升(如果我多次执行此操作)

import numpy as np

a = np.array([[1.0,2.0],[3.0,4.0]])
b = np.array([[2.0,2.0],[2.0,2.0]])
out = np.empty([2,2])

np.dot(a,b, out = out)

如果我需要修改数组,有什么办法可以利用这个功能吗?例如,如果我想:

out = np.array([[3.0,3.0],[3.0,3.0]])
out *= np.dot(a,b)

1 个答案:

答案 0 :(得分:0)

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您甚至可以使用就地运算符语法,例如np.multiply(array, 3, out=array)

要确认阵列是否就地更新,可以在修改前后检查内存地址array *= 2