R将矩阵的行乘以向量的行的最快方法 [英] R fastest way to multiply rows of a matrix by rows of a vector

问题描述

我想将矩阵的行乘以向量的每个行(元素)，而不是整个向量(正如已经发布的另一个问题所讨论的那样).

I want to multiply rows of a matrix by EACH row (element) of a vector, not the entire vector (as the other question already posted talks about.)

例如，我要使用这两个矩阵(或者oo是向量，因为它是一列)

for example, I want to use these two matrices (or oo is a vector, since it's one column)

oo=matrix(1:3,3,1)
oop=matrix(1:9,3,3,byrow=TRUE)

输出

1  2  3 
8  10 12
21 24 27

我需要非常高效地执行此操作，因为我需要数千次处理大量数据.我用

I need to do this VERY efficiently, as I need to do it with massive amounts of data thousands of times. I used

diag(as.vector(oo))%*%oop

但这太慢了.

推荐答案

R>oop*drop(oo)
     [,1] [,2] [,3]
[1,]    1    2    3
[2,]    8   10   12
[3,]   21   24   27

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