mkl_sparse_d_mm() wrong results

di_luca__daniele1 — Wed, 01 Jul 2020 08:49:40 GMT

Hello everybody,

I ran into wrong results when I was trying to use mkl_sparse_d_mm() to multiply a symmetric sparse matrix A [12 x 12] (CSR packed, lower triangular) by a dense rectangular matrix B [12 x 3] (full), that is:

C = A * B

Both matrices A and B have column wise layout, while the A matrix's CSR indeces arrays are all 0-based.

Here the example code:

int main() { // sparse matrix A[12x12] (lower triangular, column wise layout, 0-based indexing) struct matrix_descr A_descr; A_descr.type = SPARSE_MATRIX_TYPE_TRIANGULAR; A_descr.mode = SPARSE_FILL_MODE_LOWER; A_descr.diag = SPARSE_DIAG_NON_UNIT; // A rows_start MKL_INT A_ptrb[12] = { 0, 3, 8, 12, 14, 17, 20, 22, 25, 27, 28, 29 }; // A rows_end MKL_INT A_ptre[12] = { 3, 8, 12, 14, 17, 20, 22, 25, 27, 28, 29, 30 }; // A column_indeces MKL_INT A_col_index[30] = { 0, 4, 6, 1, 3, 5, 7, 11, 2, 4, 8, 10, 3, 9, 4, 8, 10, 5, 7, 11, 6, 10, 7, 9, 11, 8, 10, 9, 10, 11 }; // A values double A_values[30] = { 3.60394e+06, -2.27463e+07, -3.14901e+06, 462747, 2.27463e+07, -1.56399e+06, -7819.96, -1.56399e+06, 1.26039e+07, 1.56399e+06, -7819.96, 1.56399e+06, 1.63638e+09, -7.91937e+07, 1.97495e+09, -1.56399e+06, 2.07831e+08, 7.3454e+08, 1.56399e+06, 2.07831e+08, 3.60394e+06, -2.27463e+07, 462747, 2.27463e+07, 1.56399e+06, 1.26039e+07, -1.56399e+06, 1.63638e+09, 1.97495e+09, 7.3454e+08 }; // handle to A matrix sparse_matrix_t A_handle; sparse_status_t outcome = mkl_sparse_d_create_csr(&A_handle, SPARSE_INDEX_BASE_ZERO, 12, 12, A_ptrb, A_ptre, A_col_index, A_values); // dense matrix B [12x3] values (full, column wise layout) double B[36] = { 0.447212, 0, -0.00115627, 0, 0.00466197, 0, 0.447212, 0, 0.00115627, 0, 0.00466197, 0, 3.77898e-21, 0, -0.447214, 0, 5.05844e-22, 0, 6.67055e-22, 0, -0.447214, 0, -4.18026e-22, 0, 0, 0.447214, 0, -0.00653261, 0, -3.29415e-20, 0, 0.447214, 0, -0.00653261, 0, -3.44084e-21 }; // C = A * B double C[36]; mkl_sparse_d_mm(SPARSE_OPERATION_NON_TRANSPOSE, 1.0, A_handle, A_descr, SPARSE_LAYOUT_COLUMN_MAJOR, B, 3, 12, 0.0, C, 12); // print C for (size_t r = 0; r != 12; r++) { for (size_t c = 0; c != 3; c++) std::cout << C[r + 12*c] << " "; std::cout << std::endl; } return 0; }

Could it be a problem with the triangular form assigned to the CSR matrix? Does the routine need the full CSR matrix maybe? The results seem to be correct if the sparse matrix has no off-diagonal terms (i.e. it it's diagonal).

topic mkl_sparse_d_mm() wrong results in Intel® oneAPI Math Kernel Library

mkl_sparse_d_mm() wrong results