/* nag_matop_real_gen_matrix_cond_usd (f01jcc) Example Program.
 *
 * Copyright 2014 Numerical Algorithms Group.
 *
 * Mark 24, 2013.
 */
#include <math.h>
#include <nag.h>
#include <nag_stdlib.h>
#include <nagf01.h>
#include <nagx02.h>
#include <nagx04.h>

#ifdef __cplusplus
extern "C" {
#endif
   static void NAG_CALL f(Integer m, Integer *iflag, Integer nz,
                          const Complex z[], Complex fz[], Nag_Comm *comm);
#ifdef __cplusplus
}
#endif

#define A(I,J) a[J*pda + I]

int main(void)
{

  /* Scalars */
  Integer        exit_status = 0;
  Integer        i, iflag, j, n, pda;
  double         conda, cond_rel, eps, norma, normfa;
  /* Arrays */
  static double ruser[1] = {-1.0};
  double         *a = 0;
  /* Nag Types */
  Nag_OrderType  order = Nag_ColMajor;
  Nag_Comm       comm;
  NagError       fail;

  INIT_FAIL(fail);
  
  /* Output preamble */
  printf("nag_matop_real_gen_matrix_cond_usd (f01jcc) ");
  printf("Example Program Results\n\n");

  /* For communication with user-supplied functions: */
  comm.user = ruser;

  fflush(stdout);

  /* Skip heading in data file */
  scanf("%*[^\n] ");

  /* Read in the problem size */
  scanf("%ld%*[^\n]", &n);

  pda = n;
  if (!(a = NAG_ALLOC((pda)*(n), double))) {
    printf("Allocation failure\n");
    exit_status = -1;
    goto END;
  }
  
  /* Read in the matrix A from data file */
  for (i = 0; i < n; i++)
    for (j = 0; j < n; j++) scanf("%lf", &A(i, j));
  scanf("%*[^\n] ");
  
  /* Print real general matrix A using the easy-to-use function
   * nag_gen_real_mat_print (x04cac).
   */ 
  nag_gen_real_mat_print (order, Nag_GeneralMatrix, Nag_NonUnitDiag,
                          n, n, a, pda, "A", 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;
  }
  /* Find absolute condition number estimate of f(A) for real matrix A using
   * nag_matop_real_gen_matrix_cond_usd (f01jcc),
   * which requires user-supplied derivatives.
   */
  nag_matop_real_gen_matrix_cond_usd (n, a, pda, f, &comm, &iflag,
                                      &conda, &norma, &normfa, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_matop_real_gen_matrix_cond_usd (f01jcc)\n%s\n",
           fail.message);
    exit_status = 1;
    goto END;
  }

  /* Print absolute condition number estimate */
  printf("\nf(A) = exp(2A)\n");
  printf("Estimated absolute condition number is: %7.2f\n",conda);
  
  /* nag_machine_precision (x02ajc)  The machine precision */
  eps = nag_machine_precision;
  
  /* Find relative condition number estimate */
  if ( normfa>eps) {
    cond_rel = conda * norma/normfa;
    printf("Estimated relative condition number is: %7.2f\n",cond_rel);
  }
  else {
    printf("The estimated norm of f(A) is effectively zero");
    printf("and so the relative condition number is undefined.\n");
  }
  
 END:
  NAG_FREE(a);
  return exit_status;
}

static void NAG_CALL f(Integer m, Integer *iflag, Integer nz,
                       const Complex z[], Complex fz[], Nag_Comm *comm)
{
  /* Scalars */
  Integer j;
#pragma omp master
  if (comm->user[0] == -1.0)
    {
      printf("(User-supplied callback f, first invocation.)\n");
      comm->user[0] = 0.0;
    }
  for (j = 0; j < nz; j++) {
    /* The m^th derivative of exp 2z for complex z*/
    fz[j].re = pow(2.0,m)*exp(2.0*z[j].re)*cos(2.0*z[j].im);
    fz[j].im = pow(2.0,m)*exp(2.0*z[j].re)*sin(2.0*z[j].im);
  }
  /* Set iflag nonzero to terminate execution for any reason. */
  *iflag = 0;
}