/* nag_matop_real_gen_matrix_actexp (f01gac) Example Program. * * Copyright 2013 Numerical Algorithms Group. * * Mark 24, 2013. */ #include #include #include #include #include #include int main(void) { /* Scalars */ Integer exit_status = 0; Integer i, j, m, n, lda, ldb; double t; /* Arrays */ double *a = 0; double *b = 0; /* Nag Types */ Nag_OrderType order; NagError fail; INIT_FAIL(fail); #define A(I, J) a[(J-1)*lda + I-1] #define B(I, J) b[(J-1)*ldb + I-1] order = Nag_ColMajor; /* Output preamble */ printf("nag_matop_real_gen_matrix_actexp (f01gac) "); printf("Example Program Results\n\n"); fflush(stdout); /* Skip heading in data file */ scanf("%*[^\n]"); /* Read in the problem size and the value of the parameter t */ scanf("%ld %ld %lf%*[^\n]", &n, &m, &t); lda = n; ldb = n; if (!(a = NAG_ALLOC(n*n, double)) || !(b = NAG_ALLOC(n*m, double))) { printf("Allocation failure\n"); exit_status = -1; goto END; } /* Read in the matrix a from data file */ for (i = 1; i <= n; i++) for (j = 1; j <= n; j++) scanf("%lf", &A(i, j)); scanf("%*[^\n]"); /* Read in the matrix b from data file */ for (i = 1; i <= n; i++) for (j = 1; j <= m; j++) scanf("%lf", &B(i, j)); scanf("%*[^\n]"); /* Find exp(tA) B using * nag_matop_real_gen_matrix_actexp (f01gac) * Action of the the exponential of a real matrix on a real matrix */ nag_matop_real_gen_matrix_actexp(n, m, a, lda, b, ldb, t, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_matop_real_gen_matrix_actexp (f01gac)\n%s\n", fail.message); exit_status = 1; goto END; } /* Print solution using * nag_gen_real_mat_print (x04cac) * Print real general matrix (easy-to-use) */ nag_gen_real_mat_print(order, Nag_GeneralMatrix, Nag_NonUnitDiag, n, m, b, ldb, "exp(tA) B", NULL, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_gen_real_mat_print (x04cac)\n%s\n", fail.message); exit_status = 2; goto END; } END: NAG_FREE(a); NAG_FREE(b); return exit_status; }