稀疏矩阵 part 3

▶ 各种稀疏矩阵数据结构下 y(n,1) = A(n,m) * x(m,1) 的实现，CPU版本

● MAT 乘法

 int dotCPU(const MAT *a, const MAT *x, MAT *y)
 {
     checkNULL(a); checkNULL(x); checkNULL(y);
     if (a->col != x->row)
     {
         printf("dotMATCPU dimension mismatch!\n");
         return ;
     }

     y->row = a->row;
     y->col = x->col;
     for (int i = ; i < a->row; i++)
     {
         format sum = ;
         for (int j = ; j < a->col; j++)
             sum += a->data[i * a->col + j] * x->data[j];
         y->data[i] = sum;
     }
     COUNT_MAT(y);
     return ;
 }

● CSR 乘法

 int dotCPU(const CSR *a, const MAT *x, MAT *y)
 {
     checkNULL(a); checkNULL(x); checkNULL(y);
     if (a->col != x->row)
     {
         printf("dotCSRCPU dimension mismatch!\n");
         return ;
     }

     y->row = a->row;
     y->col = x->col;
     for (int i = ; i < a->row; i++)                            // i 遍历 ptr，j 遍历行内数据，A 中为 0 的元素不参加乘法
     {
         format sum = ;
         for (int j = a->ptr[i]; j < a->ptr[i + ]; j++)
             sum += a->data[j] * x->data[a->index[j]];
         y->data[i] = sum;
     }
     COUNT_MAT(y);
     return ;
 }

● ELL 乘法

 int dotCPU(const ELL *a, const MAT *x, MAT *y)      // CPU ELL乘法
 {
     checkNULL(a); checkNULL(x); checkNULL(y);
     if (a->colOrigin != x->row)
     {
         printf("dotELLCPU dimension mismatch!\n");
         return ;
     }

     y->row = a->col;
     y->col = x->col;
     for (int i = ; i<a->col; i++)
     {
         format sum = ;
         for (int j = ; j < a->row; j++)
         {
             int temp = a->index[j * a->col + i];
             if (temp < )                                   // 跳过无效元素
                 continue;
             sum += a->data[j * a->col + i] * x->data[temp];
         }
         y->data[i] = sum;
     }
     COUNT_MAT(y);
     return ;
 }

● COO 乘法

 int dotCPU(const COO *a, const MAT *x, MAT *y)
 {
     checkNULL(a); checkNULL(x); checkNULL(y);
     if (a->col != x->row)
     {
         printf("dotCOOCPU null!\n");
         return ;
     }

     y->row = a->row;
     y->col = x->col;
     for (int i = ; i<a->count; i++)
         y->data[a->rowIndex[i]] += a->data[i] * x->data[a->colIndex[i]];
     COUNT_MAT(y);
     return ;
 }

● DIA 乘法

 int dotCPU(const DIA *a, const MAT *x, MAT *y)
 {
     checkNULL(a); checkNULL(x); checkNULL(y);
     if (a->colOrigin != x->row)
     {
         printf("dotDIACPU null!\n");
         return ;
     }
     y->row = a->row;
     y->col = x->col;
     int * inverseIndex = (int *)malloc(sizeof(int) * a->col);
     for (int i = , j = ; i < a->row + a->col - ; i++)
     {
         if (a->index[i] == )
         {
             inverseIndex[j] = i;
             j++;
         }
     }
     for (int i = ; i < a->row; i++)
     {
         format sum = ;
         for (int j = ; j < a->col; j++)
         {
             if (i < a->row -  - inverseIndex[j] || i > inverseIndex[a->col - ] - inverseIndex[j])
                 continue;
             sum += a->data[i * a->col + j] * x->data[i + inverseIndex[j] - a->row + ];
         }
         y->data[i] = sum;
     }
     COUNT_MAT(y);
     free(inverseIndex);
     return ;
 }