c - 使用产生错误结果的数组进行矩阵乘法
问题描述
下面的代码将两个不同阶的矩阵相乘，返回结果即mat1 (6x3) * mat2 (3x6) ，返回dest中的6x6矩阵
问题是结果与计算值不匹配。此外，如果您观察结果 mat2正在更改其内容。
PS：迭代：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);
}
解决方案
float res[][6] = { 0 };是 afloat res[1][6];而不是 afloat res[6][6];你需要的。如果您没有完整的初始化列表，则需要写出所有维度。
也void main()应该是int main(void)。
您的初始化程序列表G也不适合float G[][6]，它应该是float G[][3].
这是完整的代码：https ://ideone.com/2hz45m
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