/* nag_dtgsen (f08ygc) Example Program.
 *
 * Copyright 2011 Numerical Algorithms Group.
 *
 * Mark 23, 2011.
 */

#include <stdio.h>
#include <math.h>
#include <nag.h>
#include <nag_stdlib.h>
#include <nagf08.h>
#include <nagf16.h>
#include <nagx02.h>
#include <nagx04.h>

int main(void)
{

  /* Scalars */
  double        pl, pr, small;
  Integer       i, ijob, j, m, n, pdq, pds, pdt, pdz;
  Integer       exit_status = 0;

  /* Arrays */
  double        *alphai = 0, *alphar = 0, *beta = 0, *q = 0, *s = 0, *t = 0,
                *z = 0;
  double        dif[2];
  char          nag_enum_arg[40];

  /* Nag Types */
  NagError      fail;
  Nag_OrderType order;
  Nag_Boolean   wantq, wantz;
  Nag_Boolean   *select = 0;

#ifdef NAG_COLUMN_MAJOR
#define S(I, J) s[(J-1)*pds + I - 1]
#define T(I, J) t[(J-1)*pdt + I - 1]
#define Q(I, J) q[(J-1)*pdq + I - 1]
#define Z(I, J) z[(J-1)*pdz + I - 1]
  order = Nag_ColMajor;
#else
#define S(I, J) s[(I-1)*pds + J - 1]
#define T(I, J) t[(I-1)*pdt + J - 1]
#define Q(I, J) q[(I-1)*pdq + J - 1]
#define Z(I, J) z[(I-1)*pdz + J - 1]
  order = Nag_RowMajor;
#endif

  INIT_FAIL(fail);

  printf("nag_dtgsen (f08ygc) Example Program Results\n\n");

  /* Skip heading in data file */
  scanf("%*[^\n]");
  scanf("%ld%ld%*[^\n]", &n, &ijob);
  if (n < 0 || ijob<0 || ijob>5)
    {
      printf("Invalid n or ijob\n");
      exit_status = 1;
      goto END;
    }
  scanf(" %s%*[^\n]", nag_enum_arg);
  /* nag_enum_name_to_value(x04nac).
   * Converts NAG enum member name to value
   */
  wantq = (Nag_Boolean) nag_enum_name_to_value(nag_enum_arg);
  scanf(" %s%*[^\n]", nag_enum_arg);
  wantz = (Nag_Boolean) nag_enum_name_to_value(nag_enum_arg);

  pds = n;
  pdt = n;
  pdq = (wantq?n:1);
  pdz = (wantz?n:1);

  /* Allocate memory */
  if (!(s      = NAG_ALLOC(n*n, double)) ||
      !(t      = NAG_ALLOC(n*n, double)) ||
      !(alphai = NAG_ALLOC(n, double)) ||
      !(alphar = NAG_ALLOC(n, double)) ||
      !(beta   = NAG_ALLOC(n, double)) ||
      !(select = NAG_ALLOC(n, Nag_Boolean)) ||
      !(q      = NAG_ALLOC(pdq*pdq, double)) ||
      !(z      = NAG_ALLOC(pdz*pdz, double)))
    {
      printf("Allocation failure\n");
      exit_status = -1;
      goto END;
    }

  /* nag_enum_name_to_value(x04nac).
   * Converts NAG enum member name to value
   */
  for (i = 0; i < n; ++i)
    {
      scanf("%s", nag_enum_arg);
      select[i] = (Nag_Boolean) nag_enum_name_to_value(nag_enum_arg);
    }
  scanf("%*[^\n]");

  /* Read S, T, Q, Z and the logical array select from data file */
  for (i = 1; i <= n; ++i)
    for (j = 1; j <= n; ++j) scanf("%lf", &S(i, j));
  scanf("%*[^\n]");
  for (i = 1; i <= n; ++i)
    for (j = 1; j <= n; ++j) scanf("%lf", &T(i, j));
  scanf("%*[^\n]");

  if (wantq) {
    for (i = 1; i <= n; ++i)
      for (j = 1; j <= n; ++j) scanf("%lf", &Q(i, j));
    scanf("%*[^\n]");
  }
  if (wantz) {
    for (i = 1; i <= n; ++i)
      for (j = 1; j <= n; ++j) scanf("%lf", &Z(i, j));
    scanf("%*[^\n]");
  }

  /* Reorder the Schur factors S and T and update the matrices Q and Z */
  nag_dtgsen(order, ijob, wantq, wantz, select, n, s, pds, t, pdt, alphar,
             alphai, beta, q, pdq, z, pdz, &m, &pl, &pr, dif, &fail);

  if (fail.code != NE_NOERROR)
    {
      printf("Error from nag_dtgsen (f08ygc).\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }

  /* nag_real_safe_small_number (x02amc). */
  small = nag_real_safe_small_number;

  /* Print the eigenvalues */
  printf("Selected Eigenvalues\n");
  for (j = 0; j < m; ++j)
    {
      printf("%2ld ", j+1);
      if ((fabs(alphar[j]) + fabs(alphai[j])) * small >= fabs(beta[j]))
        printf("  infinite or undetermined, alpha = (%11.4e, %11.4e), "
               "beta = %11.4e\n", alphar[j], alphai[j], beta[j]);
      else if (alphai[j] == 0.0)
        printf("  %12.4e\n", alphar[j]/beta[j]);
      else
        printf("  (%11.4e, %11.4e)\n", alphar[j]/beta[j], alphai[j]/beta[j]);
    }
 
  if (ijob==1 || ijob==4 || ijob == 5) {
    printf("\n");
    printf("For the selected eigenvalues,\nthe reciprocals of projection "
           "norms onto the deflating subspaces are\n");
    printf(" for left  subspace, pl = %11.2e\n for right subspace, pr = "
           "%11.2e\n\n", pl, pr);
  }
  if (ijob>1) {
    printf(" upper bound on Difu    = %11.2e\n", dif[0]);
    printf(" upper bound on Difl    = %11.2e\n", dif[1]);
    if (ijob==2 || ijob==4) {
      printf("\nUpper bounds on Difl, Difu are based on the Frobenius norm\n");
    }
    if (ijob==3 || ijob==5) {
      printf("\nUpper bounds on Difl, Difu are based on the one norm.\n");
    }
  }

 END:
  if (s)      NAG_FREE(s);
  if (t)      NAG_FREE(t);
  if (alphai) NAG_FREE(alphai);
  if (alphar) NAG_FREE(alphar);
  if (beta)   NAG_FREE(beta);
  if (select) NAG_FREE(select);
  if (q)      NAG_FREE(q);
  if (z)      NAG_FREE(z);

  return exit_status;
}