/* nag_dgetrf (f07adc) Example Program. * * Copyright 2001 Numerical Algorithms Group. * * Mark 7, 2001. */ #include #include #include #include #include int main(void) { /* Scalars */ Integer i, ipiv_len, j, m, n, pda; Integer exit_status = 0; NagError fail; Nag_OrderType order; /* Arrays */ double *a = 0; Integer *ipiv = 0; #ifdef NAG_COLUMN_MAJOR #define A(I, J) a[(J-1)*pda + I - 1] order = Nag_ColMajor; #else #define A(I, J) a[(I-1)*pda + J - 1] order = Nag_RowMajor; #endif INIT_FAIL(fail); printf("nag_dgetrf (f07adc) Example Program Results\n\n"); /* Skip heading in data file */ scanf("%*[^\n] "); scanf("%ld%ld%*[^\n] ", &m, &n); ipiv_len = MIN(m, n); #ifdef NAG_COLUMN_MAJOR pda = m; #else pda = n; #endif /* Allocate memory */ if (!(a = NAG_ALLOC(m * n, double)) || !(ipiv = NAG_ALLOC(ipiv_len, Integer))) { printf("Allocation failure\n"); exit_status = -1; goto END; } /* Read A from data file */ for (i = 1; i <= m; ++i) { for (j = 1; j <= n; ++j) scanf("%lf", &A(i, j)); } scanf("%*[^\n] "); /* Factorize A */ /* nag_dgetrf (f07adc). * LU factorization of real m by n matrix */ nag_dgetrf(order, m, n, a, pda, ipiv, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_dgetrf (f07adc).\n%s\n", fail.message); exit_status = 1; goto END; } /* Print details of factorization */ /* nag_gen_real_mat_print (x04cac). * Print real general matrix (easy-to-use) */ fflush(stdout); nag_gen_real_mat_print(order, Nag_GeneralMatrix, Nag_NonUnitDiag, m, n, a, pda, "Details of factorization", 0, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_gen_real_mat_print (x04cac).\n%s\n", fail.message); exit_status = 1; goto END; } /* Print pivot indices */ printf("\nipiv\n"); for (i = 1; i <= MIN(m, n); ++i) printf("%6ld%s", ipiv[i-1], i%7 == 0?"\n":" "); printf("\n"); END: NAG_FREE(a); NAG_FREE(ipiv); return exit_status; }