Fortran向量和矩陣乘法函數

下表描述了向量和矩陣乘法函數：

函數

描述

dot_product(vector_a, vector_b)

函數返回兩個輸入向量，它必須具有相同長度的標量積。

matmul (matrix_a, matrix_b)

它返回兩個矩陣的矩陣乘積，它必須是一致的，即具有相似大小 (m, k) 和 (k, n)

實例

下面的例子演示了內積：

program arrayDotProduct

real, dimension(5) :: a, b
integer:: i, asize, bsize

asize = size(a) bsize = size(b) do i = 1, asize
a(i) = i end do do i = 1, bsize
b(i) = i*2 end do do i = 1, asize Print *, a(i) end do do i = 1, bsize Print *, b(i) end do Print*, 'Vector Multiplication: Dot Product:' Print*, dot_product(a, b) end program arrayDotProduct

當上述代碼被編譯和執行時，它產生了以下結果：

1.00000000
2.00000000
3.00000000
4.00000000
5.00000000
2.00000000
4.00000000
6.00000000
8.00000000
10.0000000
Vector Multiplication: Dot Product:
110.000000

實例

下面的例子演示了矩陣乘法：

program matMulProduct

integer, dimension(3,3) :: a, b, c
integer :: i, j do i = 1, 3 do j = 1, 3 a(i, j) = i+j end do end do print *, 'Matrix Multiplication: A Matrix' do i = 1, 3 do j = 1, 3 print*, a(i, j) end do end do do i = 1, 3 do j = 1, 3 b(i, j) = i*j end do end do Print*, 'Matrix Multiplication: B Matrix' do i = 1, 3 do j = 1, 3 print*, b(i, j) end do end do c = matmul(a, b) Print*, 'Matrix Multiplication: Result Matrix' do i = 1, 3 do j = 1, 3 print*, c(i, j) end do end do end program matMulProduct

當上述代碼被編譯和執行時，它產生了以下結果：

Matrix Multiplication: A Matrix
2
3
4
3
4
5
4
5
6
Matrix Multiplication: B Matrix
1
2
3
2
4
6
3
6
9
Matrix Multiplication: Result Matrix
20
40
60
26
52
78
32
64
96