Question

我试图将数组A的每一行乘以另一个数组（B）中的每一行，以获得与前两个数组具有相同行数和列数的len（A）数组。

任何帮助？

pseudo-code
from numpy  import *
import numpy as np

def multipar():
    A = array( [ (0.1,0.5,0.2,0.2), (0.2,0.5,0.1,0.2), (0.7,0.1,0.1,0.1) ] )
    B = array( [ (1,2,3,4), (2,3,4,5), (3,4,5,6) ] )
    for i in len(A):
        average = A[i]*B
    print average

multipar()

我想得到每个新数组

Array C
(0.1,0.5,0.2,0.2) * (1,2,3,4);
(0.1,0.5,0.2,0.2) * (2,3,4,5);
(...)
Array D
(0.2,0.5,0.1,0.2) * (1,2,3,4);
(...)

Answer 1

你可以用更高的尺寸做一些有趣的事情。将A或B扩展到第三维，然后将其与未扩展的维度相乘。 e.g：

A = array( [ (0.1,0.5,0.2,0.2), (0.2,0.5,0.1,0.2), (0.7,0.1,0.1,0.1) ] )
B = array( [ (1,2,3,4), (2,3,4,5), (3,4,5,6) ] )

tiled = tile (B, (3,1,1)).swapaxes (0,1)
all_results = A*tiled

现在，您拥有all_results中的所有结果数组;您可以使用all_results[0]，all_results[1]等轻松获取它们

编辑：回复最新的问题编辑：如果你真的需要单独的结果数组，那么还有两个选项：

C, D, E = all_results
用我的第一个建议替换最后两个语句：

C = B * A [0]

D = B * A [1]

E = B * A [2]

如果您确实需要单独的数组用于结果，并且需要更多行以便需要循环，那么您可以执行类似的操作（感谢@Jaime用于广播符号）

all_results = A[:, None, :] * B[None, :, :]
for i, res in enumerate (all_results):
    locals () ['result%d'%i] = res

现在乘以第一行的结果是名为res1的变量，res2中的第二行，依此类推。

Python \ Numpy中的数组行乘法循环

1 个答案: