/* nag_enum_name_to_value (x04nac) Example Program.
*
* Copyright 2019 Numerical Algorithms Group.
*
* Mark 27.0, 2019.
*/
#include <stdio.h>
#include <nag.h>
int main(void)
{
/* Scalars */
Integer i, j, n, nrhs, pda, pdb;
Integer exit_status = 0;
NagError fail;
Nag_OrderType order;
Nag_TransType trans;
Nag_MatrixType matrix;
Nag_DiagType unitdiag;
/* Arrays */
double *a = 0, *b = 0;
Integer *ipiv = 0;
char nag_enum_arg[20];
INIT_FAIL(fail);
printf("nag_enum_name_to_value (x04nac) Example Program Results\n\n");
/* Skip heading in data file */
scanf("%*[^\n] ");
/* Read the problem dimensions. */
scanf("%" NAG_IFMT "%" NAG_IFMT "%*[^\n] ", &n, &nrhs);
/* Read the storage order of the matrices and convert to value. */
scanf("%19s%*[^\n] ", nag_enum_arg);
/* nag_enum_name_to_value (x04nac).
* Converts NAG enum member name to value
*/
order = (Nag_OrderType) nag_enum_name_to_value(nag_enum_arg);
/* Read whether matrix A is to be transposed and convert. */
scanf("%19s%*[^\n] ", nag_enum_arg);
trans = (Nag_TransType) nag_enum_name_to_value(nag_enum_arg);
/* Read and convert parameters for writing solution using
* nag_file_print_matrix_real_gen (x04cac). */
scanf("%19s%*[^\n] ", nag_enum_arg);
matrix = (Nag_MatrixType) nag_enum_name_to_value(nag_enum_arg);
scanf("%19s%*[^\n] ", nag_enum_arg);
unitdiag = (Nag_DiagType) nag_enum_name_to_value(nag_enum_arg);
/* Set up defines for reading matrices using given order. */
#define A(I, J) a[(J-1)*pda + I - 1]
#define B(I, J) b[(J-1)*pdb + I - 1]
if (order == (int) Nag_ColMajor) {
pda = n;
pdb = n;
}
else {
pda = n;
pdb = nrhs;
}
/* Allocate memory */
if (!(a = NAG_ALLOC(n * n, double)) ||
!(b = NAG_ALLOC(n * nrhs, double)) || !(ipiv = NAG_ALLOC(n, Integer)))
{
printf("Allocation failure\n");
exit_status = -1;
goto END;
}
/* Read A and B from data file */
if (order == Nag_ColMajor) {
for (i = 1; i <= n; ++i) {
for (j = 1; j <= n; ++j)
scanf("%lf", &A(i, j));
}
scanf("%*[^\n] ");
for (i = 1; i <= n; ++i) {
for (j = 1; j <= nrhs; ++j)
scanf("%lf", &B(i, j));
}
scanf("%*[^\n] ");
}
else {
for (i = 1; i <= n; ++i) {
for (j = 1; j <= n; ++j)
scanf("%lf", &A(j, i));
}
scanf("%*[^\n] ");
for (i = 1; i <= n; ++i) {
for (j = 1; j <= nrhs; ++j)
scanf("%lf", &B(j, i));
}
scanf("%*[^\n] ");
}
/* Factorize A */
/* nag_lapacklin_dgetrf (f07adc).
* LU factorization of real m by n matrix
*/
nag_lapacklin_dgetrf(order, n, n, a, pda, ipiv, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_lapacklin_dgetrf (f07adc).\n%s\n", fail.message);
exit_status = 1;
goto END;
}
/* Compute solution */
/* nag_lapacklin_dgetrs (f07aec).
* Solution of real system of linear equations, multiple
* right-hand sides, matrix already factorized by nag_lapacklin_dgetrf
* (f07adc)
*/
nag_lapacklin_dgetrs(order, trans, n, nrhs, a, pda, ipiv, b, pdb, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_lapacklin_dgetrs (f07aec).\n%s\n", fail.message);
exit_status = 1;
goto END;
}
/* nag_enum_value_to_name (x04nbc).
* Converts NAG enum member value to its name
*/
printf("Array storage scheme used in nag_lapacklin_dgetrs (f07aec) is %s\n",
nag_enum_value_to_name(order));
/* nag_error_name_to_code (x04ncc).
* Converts NAG error name to its code value
*/
printf("nag_lapacklin_dgetrs (f07aec) returns with the error code "
"(fail.code) set to %d\n\n", nag_error_name_to_code("NE_NOERROR"));
/* Print solution */
/* nag_file_print_matrix_real_gen (x04cac).
* Print real general matrix (easy-to-use)
*/
fflush(stdout);
nag_file_print_matrix_real_gen(order, matrix, unitdiag, n, nrhs, b, pdb,
"Solution(s)", 0, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_file_print_matrix_real_gen (x04cac).\n%s\n", fail.message);
exit_status = 1;
goto END;
}
END:
NAG_FREE(a);
NAG_FREE(b);
NAG_FREE(ipiv);
return exit_status;
}