Fortran 90/95 中的广播数组乘法 [英] Broadcast array multiplication in Fortran 90/95

问题描述

我想知道在 Fortran 中是否有更好(简洁)的方式来编码?我试图将 a(3, 3) 的每一列乘以 b(3) 中的每个值.我知道 Python 中有 np.multiply，但不确定 Fortran.

I was wondering that would there be a better (succinct) way to code this in Fortran? I am trying to multiply each column of a(3, 3) by each value in b(3). I know in Python there is np.multiply, and not sure about Fortran.

!!! test.f90
program test
    implicit none
    integer, parameter :: dp=kind(0.d0)
    real(dp) :: a(3, 3)=reshape([1, 2, 3, 4, 5, 6, 7, 8, 9], [3, 3]),&
        b(3)=[1, 2, 3]
    integer :: i
    do i = 1, 3
        a(:, i) = a(:, i) * b(i)
    end do
    write(*, *) a
end program test

提前致谢！

推荐答案

表达式

a * SPREAD(b,1,3)

将产生与您的循环相同的结果.我将把它留给你和其他人来判断这是否比循环更简洁或更好.

will produce the same result as your loop. I'll leave it to you and to others to judge whether this is more succinct or in any way better than the loop.

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