以下代码将两个不同阶的矩阵相乘并返回结果，即 mat1（6x3）* mat2（3x6），并以 dest
返回6x6矩阵问题是结果与计算值不匹配。另外，如果您观察到结果 mat2 正在更改其内容。
PS：迭代次数：3，0，1 mat1 [3] [1] = 0.000000 mat2 [1] [0] = 20.000000 dest [3] [0] = 0.000000
mat2 [1] [0]的原始内容为零。
输出：
iterals: 0, 0, 0 mat1[0][0] = 10.000000 mat2[0][0] = 1.000000 dest[0][0] = 10.000000
iterals: 0, 0, 1 mat1[0][1] = 0.000000 mat2[1][0] = 0.000000 dest[0][0] = 10.000000
iterals: 0, 0, 2 mat1[0][2] = 0.000000 mat2[2][0] = 0.000000 dest[0][0] = 10.000000
iterals: 0, 1, 0 mat1[0][0] = 10.000000 mat2[0][1] = 0.000000 dest[0][1] = 0.000000
iterals: 0, 1, 1 mat1[0][1] = 0.000000 mat2[1][1] = 0.000000 dest[0][1] = 0.000000
iterals: 0, 1, 2 mat1[0][2] = 0.000000 mat2[2][1] = 0.000000 dest[0][1] = 0.000000
iterals: 0, 2, 0 mat1[0][0] = 10.000000 mat2[0][2] = 0.000000 dest[0][2] = 0.000000
iterals: 0, 2, 1 mat1[0][1] = 0.000000 mat2[1][2] = 1.000000 dest[0][2] = 0.000000
iterals: 0, 2, 2 mat1[0][2] = 0.000000 mat2[2][2] = 0.000000 dest[0][2] = 0.000000
iterals: 0, 3, 0 mat1[0][0] = 10.000000 mat2[0][3] = 0.000000 dest[0][3] = 0.000000
iterals: 0, 3, 1 mat1[0][1] = 0.000000 mat2[1][3] = 0.000000 dest[0][3] = 0.000000
iterals: 0, 3, 2 mat1[0][2] = 0.000000 mat2[2][3] = 0.000000 dest[0][3] = 0.000000
iterals: 0, 4, 0 mat1[0][0] = 10.000000 mat2[0][4] = 0.000000 dest[0][4] = 0.000000
iterals: 0, 4, 1 mat1[0][1] = 0.000000 mat2[1][4] = 0.000000 dest[0][4] = 0.000000
iterals: 0, 4, 2 mat1[0][2] = 0.000000 mat2[2][4] = 1.000000 dest[0][4] = 0.000000
iterals: 0, 5, 0 mat1[0][0] = 10.000000 mat2[0][5] = 0.000000 dest[0][5] = 0.000000
iterals: 0, 5, 1 mat1[0][1] = 0.000000 mat2[1][5] = 0.000000 dest[0][5] = 0.000000
iterals: 0, 5, 2 mat1[0][2] = 0.000000 mat2[2][5] = 0.000000 dest[0][5] = 0.000000
iterals: 1, 0, 0 mat1[1][0] = 0.000000 mat2[0][0] = 1.000000 dest[1][0] = 0.000000
iterals: 1, 0, 1 mat1[1][1] = 0.000000 mat2[1][0] = 0.000000 dest[1][0] = 0.000000
iterals: 1, 0, 2 mat1[1][2] = 0.000000 mat2[2][0] = 0.000000 dest[1][0] = 0.000000
iterals: 1, 1, 0 mat1[1][0] = 0.000000 mat2[0][1] = 0.000000 dest[1][1] = 0.000000
iterals: 1, 1, 1 mat1[1][1] = 0.000000 mat2[1][1] = 0.000000 dest[1][1] = 0.000000
iterals: 1, 1, 2 mat1[1][2] = 0.000000 mat2[2][1] = 0.000000 dest[1][1] = 0.000000
iterals: 1, 2, 0 mat1[1][0] = 0.000000 mat2[0][2] = 0.000000 dest[1][2] = 0.000000
iterals: 1, 2, 1 mat1[1][1] = 0.000000 mat2[1][2] = 1.000000 dest[1][2] = 0.000000
iterals: 1, 2, 2 mat1[1][2] = 0.000000 mat2[2][2] = 0.000000 dest[1][2] = 0.000000
iterals: 1, 3, 0 mat1[1][0] = 0.000000 mat2[0][3] = 0.000000 dest[1][3] = 0.000000
iterals: 1, 3, 1 mat1[1][1] = 0.000000 mat2[1][3] = 0.000000 dest[1][3] = 0.000000
iterals: 1, 3, 2 mat1[1][2] = 0.000000 mat2[2][3] = 0.000000 dest[1][3] = 0.000000
iterals: 1, 4, 0 mat1[1][0] = 0.000000 mat2[0][4] = 0.000000 dest[1][4] = 0.000000
iterals: 1, 4, 1 mat1[1][1] = 0.000000 mat2[1][4] = 0.000000 dest[1][4] = 0.000000
iterals: 1, 4, 2 mat1[1][2] = 0.000000 mat2[2][4] = 1.000000 dest[1][4] = 0.000000
iterals: 1, 5, 0 mat1[1][0] = 0.000000 mat2[0][5] = 0.000000 dest[1][5] = 0.000000
iterals: 1, 5, 1 mat1[1][1] = 0.000000 mat2[1][5] = 0.000000 dest[1][5] = 0.000000
iterals: 1, 5, 2 mat1[1][2] = 0.000000 mat2[2][5] = 0.000000 dest[1][5] = 0.000000
iterals: 2, 0, 0 mat1[2][0] = 0.000000 mat2[0][0] = 0.000000 dest[2][0] = 0.000000
iterals: 2, 0, 1 mat1[2][1] = 20.000000 mat2[1][0] = 0.000000 dest[2][0] = 0.000000
iterals: 2, 0, 2 mat1[2][2] = 0.000000 mat2[2][0] = 0.000000 dest[2][0] = 0.000000
iterals: 2, 1, 0 mat1[2][0] = 0.000000 mat2[0][1] = 0.000000 dest[2][1] = 0.000000
iterals: 2, 1, 1 mat1[2][1] = 20.000000 mat2[1][1] = 0.000000 dest[2][1] = 0.000000
iterals: 2, 1, 2 mat1[2][2] = 0.000000 mat2[2][1] = 0.000000 dest[2][1] = 0.000000
iterals: 2, 2, 0 mat1[2][0] = 0.000000 mat2[0][2] = 0.000000 dest[2][2] = 0.000000
iterals: 2, 2, 1 mat1[2][1] = 20.000000 mat2[1][2] = 1.000000 dest[2][2] = 20.000000
iterals: 2, 2, 2 mat1[2][2] = 0.000000 mat2[2][2] = 0.000000 dest[2][2] = 20.000000
iterals: 2, 3, 0 mat1[2][0] = 0.000000 mat2[0][3] = 0.000000 dest[2][3] = 0.000000
iterals: 2, 3, 1 mat1[2][1] = 20.000000 mat2[1][3] = 0.000000 dest[2][3] = 0.000000
iterals: 2, 3, 2 mat1[2][2] = 0.000000 mat2[2][3] = 0.000000 dest[2][3] = 0.000000
iterals: 2, 4, 0 mat1[2][0] = 0.000000 mat2[0][4] = 0.000000 dest[2][4] = 0.000000
iterals: 2, 4, 1 mat1[2][1] = 20.000000 mat2[1][4] = 0.000000 dest[2][4] = 0.000000
iterals: 2, 4, 2 mat1[2][2] = 0.000000 mat2[2][4] = 1.000000 dest[2][4] = 0.000000
iterals: 2, 5, 0 mat1[2][0] = 0.000000 mat2[0][5] = 0.000000 dest[2][5] = 0.000000
iterals: 2, 5, 1 mat1[2][1] = 20.000000 mat2[1][5] = 0.000000 dest[2][5] = 0.000000
iterals: 2, 5, 2 mat1[2][2] = 0.000000 mat2[2][5] = 0.000000 dest[2][5] = 0.000000
iterals: 3, 0, 0 mat1[3][0] = 0.000000 mat2[0][0] = 0.000000 dest[3][0] = 0.000000
iterals: 3, 0, 1 mat1[3][1] = 0.000000 mat2[1][0] = 20.000000 dest[3][0] = 0.000000
iterals: 3, 0, 2 mat1[3][2] = 0.000000 mat2[2][0] = 0.000000 dest[3][0] = 0.000000
iterals: 3, 1, 0 mat1[3][0] = 0.000000 mat2[0][1] = 0.000000 dest[3][1] = 0.000000
iterals: 3, 1, 1 mat1[3][1] = 0.000000 mat2[1][1] = 0.000000 dest[3][1] = 0.000000
iterals: 3, 1, 2 mat1[3][2] = 0.000000 mat2[2][1] = 0.000000 dest[3][1] = 0.000000
iterals: 3, 2, 0 mat1[3][0] = 0.000000 mat2[0][2] = 0.000000 dest[3][2] = 0.000000
iterals: 3, 2, 1 mat1[3][1] = 0.000000 mat2[1][2] = 0.000000 dest[3][2] = 0.000000
iterals: 3, 2, 2 mat1[3][2] = 0.000000 mat2[2][2] = 0.000000 dest[3][2] = 0.000000
iterals: 3, 3, 0 mat1[3][0] = 0.000000 mat2[0][3] = 0.000000 dest[3][3] = 0.000000
iterals: 3, 3, 1 mat1[3][1] = 0.000000 mat2[1][3] = 0.000000 dest[3][3] = 0.000000
iterals: 3, 3, 2 mat1[3][2] = 0.000000 mat2[2][3] = 0.000000 dest[3][3] = 0.000000
iterals: 3, 4, 0 mat1[3][0] = 0.000000 mat2[0][4] = 0.000000 dest[3][4] = 0.000000
iterals: 3, 4, 1 mat1[3][1] = 0.000000 mat2[1][4] = 0.000000 dest[3][4] = 0.000000
iterals: 3, 4, 2 mat1[3][2] = 0.000000 mat2[2][4] = 1.000000 dest[3][4] = 0.000000
iterals: 3, 5, 0 mat1[3][0] = 0.000000 mat2[0][5] = 0.000000 dest[3][5] = 0.000000
iterals: 3, 5, 1 mat1[3][1] = 0.000000 mat2[1][5] = 0.000000 dest[3][5] = 0.000000
iterals: 3, 5, 2 mat1[3][2] = 0.000000 mat2[2][5] = 0.000000 dest[3][5] = 0.000000
iterals: 4, 0, 0 mat1[4][0] = 0.000000 mat2[0][0] = 0.000000 dest[4][0] = 0.000000
iterals: 4, 0, 1 mat1[4][1] = 0.000000 mat2[1][0] = 20.000000 dest[4][0] = 0.000000
iterals: 4, 0, 2 mat1[4][2] = 30.000000 mat2[2][0] = 0.000000 dest[4][0] = 0.000000
iterals: 4, 1, 0 mat1[4][0] = 0.000000 mat2[0][1] = 0.000000 dest[4][1] = 0.000000
iterals: 4, 1, 1 mat1[4][1] = 0.000000 mat2[1][1] = 0.000000 dest[4][1] = 0.000000
iterals: 4, 1, 2 mat1[4][2] = 30.000000 mat2[2][1] = 0.000000 dest[4][1] = 0.000000
iterals: 4, 2, 0 mat1[4][0] = 0.000000 mat2[0][2] = 0.000000 dest[4][2] = 0.000000
iterals: 4, 2, 1 mat1[4][1] = 0.000000 mat2[1][2] = 0.000000 dest[4][2] = 0.000000
iterals: 4, 2, 2 mat1[4][2] = 30.000000 mat2[2][2] = 0.000000 dest[4][2] = 0.000000
iterals: 4, 3, 0 mat1[4][0] = 0.000000 mat2[0][3] = 0.000000 dest[4][3] = 0.000000
iterals: 4, 3, 1 mat1[4][1] = 0.000000 mat2[1][3] = 0.000000 dest[4][3] = 0.000000
iterals: 4, 3, 2 mat1[4][2] = 30.000000 mat2[2][3] = 0.000000 dest[4][3] = 0.000000
iterals: 4, 4, 0 mat1[4][0] = 0.000000 mat2[0][4] = 0.000000 dest[4][4] = 0.000000
iterals: 4, 4, 1 mat1[4][1] = 0.000000 mat2[1][4] = 0.000000 dest[4][4] = 0.000000
iterals: 4, 4, 2 mat1[4][2] = 30.000000 mat2[2][4] = 0.000000 dest[4][4] = 0.000000
iterals: 4, 5, 0 mat1[4][0] = 0.000000 mat2[0][5] = 0.000000 dest[4][5] = 0.000000
iterals: 4, 5, 1 mat1[4][1] = 0.000000 mat2[1][5] = 0.000000 dest[4][5] = 0.000000
iterals: 4, 5, 2 mat1[4][2] = 30.000000 mat2[2][5] = 0.000000 dest[4][5] = 0.000000
iterals: 5, 0, 0 mat1[5][0] = 0.000000 mat2[0][0] = 0.000000 dest[5][0] = 0.000000
iterals: 5, 0, 1 mat1[5][1] = 0.000000 mat2[1][0] = 20.000000 dest[5][0] = 0.000000
iterals: 5, 0, 2 mat1[5][2] = 0.000000 mat2[2][0] = 0.000000 dest[5][0] = 0.000000
iterals: 5, 1, 0 mat1[5][0] = 0.000000 mat2[0][1] = 0.000000 dest[5][1] = 0.000000
iterals: 5, 1, 1 mat1[5][1] = 0.000000 mat2[1][1] = 0.000000 dest[5][1] = 0.000000
iterals: 5, 1, 2 mat1[5][2] = 0.000000 mat2[2][1] = 0.000000 dest[5][1] = 0.000000
iterals: 5, 2, 0 mat1[5][0] = 0.000000 mat2[0][2] = 0.000000 dest[5][2] = 0.000000
iterals: 5, 2, 1 mat1[5][1] = 0.000000 mat2[1][2] = 0.000000 dest[5][2] = 0.000000
iterals: 5, 2, 2 mat1[5][2] = 0.000000 mat2[2][2] = 0.000000 dest[5][2] = 0.000000
iterals: 5, 3, 0 mat1[5][0] = 0.000000 mat2[0][3] = 0.000000 dest[5][3] = 0.000000
iterals: 5, 3, 1 mat1[5][1] = 0.000000 mat2[1][3] = 0.000000 dest[5][3] = 0.000000
iterals: 5, 3, 2 mat1[5][2] = 0.000000 mat2[2][3] = 0.000000 dest[5][3] = 0.000000
iterals: 5, 4, 0 mat1[5][0] = 0.000000 mat2[0][4] = 0.000000 dest[5][4] = 0.000000
iterals: 5, 4, 1 mat1[5][1] = 0.000000 mat2[1][4] = 0.000000 dest[5][4] = 0.000000
iterals: 5, 4, 2 mat1[5][2] = 0.000000 mat2[2][4] = 0.000000 dest[5][4] = 0.000000
iterals: 5, 5, 0 mat1[5][0] = 0.000000 mat2[0][5] = 0.000000 dest[5][5] = 0.000000
iterals: 5, 5, 1 mat1[5][1] = 0.000000 mat2[1][5] = 0.000000 dest[5][5] = 0.000000
iterals: 5, 5, 2 mat1[5][2] = 0.000000 mat2[2][5] = 0.000000 dest[5][5] = 0.000000
这是源代码：
#include<stdio.h>
void prod(float mat1[][6], float mat2[][6], float dest[][6], int m1, int n1, int n2) {
printf("orders: %d, %d, %d\n", m1, n1, n2);
int i, j, k; // kmax = n1, jmax = n2, imax = m1
for (i = 0; i < m1; i++) {
for (j = 0; j < n2; j++) {
dest[i][j] = 0;
for (k = 0; k < n1; k++) {
dest[i][j] += mat1[i][k]*mat2[k][j];
printf("iterals: %d, %d, %d\t", i, j, k);
printf("mat1[%d][%d] = %f\t", i, k, mat1[i][k]);
printf("mat2[%d][%d] = %f\t", k, j, mat2[k][j]);
printf("dest[%d][%d] = %f\n", i, j, dest[i][j]);
}
}
}
}
void main() {
float res[][6] = { 0 };
float G[][6] = { {10, 0, 0},
{ 0, 0, 0},
{ 0, 20, 0},
{ 0, 0, 0},
{ 0, 0, 30},
{ 0, 0, 0} };
float H[][6] = { {1, 0, 0, 0, 0, 0},
{0, 0, 1, 0, 0, 0},
{0, 0, 0, 0, 1, 0} };
prod(G, H, res, 6, 3, 6);
}
答案 0 :(得分：2)
float res[][6] = { 0 };是float res[1][6];，而不是您需要的float res[6][6];。如果没有完整的初始化程序列表，则需要写出所有尺寸。
也void main()应该是int main(void)。
您的G初始化列表也不适合float G[][6]，它应该是float G[][3]。
完整代码如下：https://ideone.com/2hz45m
答案 1 :(得分：1)
除了float res[][6] = { 0 };太小以外，其他@mch，@Rishikesh Raje都说过，还存在其他问题。
将mat1[][6], mat2[][6], dest[][6]视为mat1[a][b], mat2[b][c], dest[a][c]，以获得更清晰，更灵活的代码。
在C99中以及在C11中（可选），参数可以是variable length array - VLA，从而简化了编码。
参见Passing a multidimensional variable length array to a function
void prod(int a, int b, int c, float mat1[a][b], float mat2[b][c], float dest[a][c]) {
printf("orders: %d, %d, %d\n", a, b, c);
for (int ai = 0; ai < a; ai++) {
for (int ci = 0; ci < c; ci++) {
float sum = 0.0;
for (int bi = 0; bi < b; bi++) {
sum += mat1[ai][bi] * mat2[bi][ci];
printf("iterals: %d, %d, %d\t", ai, ci, bi);
printf("mat1[%d][%d] = %2g\t", ai, bi, mat1[ai][bi]);
printf("mat2[%d][%d] = %2g\t", bi, ci, mat2[bi][ai]);
printf("dest[%d][%d] = %2g\n", ai, ci, sum);
}
dest[ai][ci] = sum;
}
}
}
#define A 6
#define B 3
#define C 6
int main(void) {
float g[A][B] = { //
{10, 0, 0}, //
{0, 0, 0}, //
{0, 20, 0}, //
{0, 0, 0}, //
{0, 0, 30}, //
{0, 0, 0}};
float h[B][C] = { // Note dimension change
{1, 0, 0, 0, 0, 0}, //
{0, 0, 1, 0, 0, 0}, //
{0, 0, 0, 0, 1, 0}};
float res[A][C]; // Note dimension change
prod(A, B, C, g, h, res);
}
答案 2 :(得分：0)
您的G矩阵没有6列。它有3列，应定义如下
float G[][3]
结果矩阵需要一个大小。
float res[6][6] = { 0 };
您应将main定义为int main(void)
功能定义也应如下更改。
void prod(float mat1[][3], float mat2[][6], float dest[][6], int m1, int n1, int n2) {