/* nag_complex_tridiag_lin_solve (f04ccc) Example Program.
 *
 * Copyright 2004 Numerical Algorithms Group.
 *
 * Mark 8, 2004.
 */

#include <stdio.h>
#include <nag.h>
#include <nag_stdlib.h>
#include <nagf04.h>
#include <nagx04.h>

int main(void)
{
  /* Scalars */
  double        errbnd, rcond;
  Integer       exit_status, i, j, n, nrhs, pdb;

  /* Arrays */
  char          *clabs = 0, *rlabs = 0;
  Complex       *b = 0, *d = 0, *dl = 0, *du = 0, *du2 = 0;
  Integer       *ipiv = 0;

  /* Nag types */
  NagError      fail;
  Nag_OrderType order;

#ifdef NAG_COLUMN_MAJOR
#define B(I, J) b[(J-1)*pdb + I - 1]
  order = Nag_ColMajor;
#else
#define B(I, J) b[(I-1)*pdb + J - 1]
  order = Nag_RowMajor;
#endif

  exit_status = 0;
  INIT_FAIL(fail);

  printf(
          "nag_complex_tridiag_lin_solve (f04ccc) Example Program Results\n\n");

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

  scanf("%ld%ld%*[^\n] ", &n, &nrhs);
  if (n > 0 && nrhs > 0)
    {
      /* Allocate memory */
      if (!(clabs = NAG_ALLOC(2, char)) ||
          !(rlabs = NAG_ALLOC(2, char)) ||
          !(b = NAG_ALLOC(n*nrhs, Complex)) ||
          !(d = NAG_ALLOC(n, Complex)) ||
          !(dl = NAG_ALLOC(n-1, Complex)) ||
          !(du = NAG_ALLOC(n-1, Complex)) ||
          !(du2 = NAG_ALLOC(n-2, Complex)) ||
          !(ipiv = NAG_ALLOC(n, Integer)))
        {
          printf("Allocation failure\n");
          exit_status = -1;
          goto END;
        }
#ifdef NAG_COLUMN_MAJOR
      pdb = n;
#else
      pdb = nrhs;
#endif
    }
  else
    {
      printf("%s\n", "n and/or nrhs too small");
      exit_status = 1;
      return exit_status;
    }
  /* Read A and B from data file */

  for (i = 1; i <= n - 1; ++i)
    {
      scanf(" ( %lf , %lf )", &du[i - 1].re, &du[i - 1].im);
    }
  scanf("%*[^\n] ");

  for (i = 1; i <= n; ++i)
    {
      scanf(" ( %lf , %lf )", &d[i - 1].re, &d[i - 1].im);
    }
  scanf("%*[^\n] ");

  for (i = 1; i <= n - 1; ++i)
    {
      scanf(" ( %lf , %lf )", &dl[i - 1].re, &dl[i - 1].im);
    }
  scanf("%*[^\n] ");

  for (i = 1; i <= n; ++i)
    {
      for (j = 1; j <= nrhs; ++j)
        {
          scanf(" ( %lf , %lf )", &B(i, j).re, &B(i, j).im);
        }
    }
  scanf("%*[^\n] ");

  /* Solve the equations AX = B for X */
  /* nag_complex_tridiag_lin_solve (f04ccc).
   * Computes the solution and error-bound to a complex
   * tridiagonal system of linear equations
   */
  nag_complex_tridiag_lin_solve(order, n, nrhs, dl, d, du, du2, ipiv, b, pdb,
                                &rcond, &errbnd, &fail);
  if (fail.code == NE_NOERROR)
    {
      /* Print solution, estimate of condition number and approximate */
      /* error bound */
      /* nag_gen_complx_mat_print_comp (x04dbc).
       * Print complex general matrix (comprehensive)
       */
      fflush(stdout);
      nag_gen_complx_mat_print_comp(order, Nag_GeneralMatrix, Nag_NonUnitDiag,
                                    n, nrhs, b, pdb, Nag_BracketForm,
                                    0, "Solution", Nag_IntegerLabels, 0,
                                    Nag_IntegerLabels, 0, 80, 0, 0,
                                    &fail);
      if (fail.code != NE_NOERROR)
        {
          printf(
                  "Error from nag_gen_complx_mat_print_comp (x04dbc).\n%s\n",
                  fail.message);
          exit_status = 1;
          goto END;
        }

      printf("\n");
      printf("%s\n%8s%10.1e\n", "Estimate of condition number", "",
              1.0/rcond);
      printf("\n\n");
      printf("%s\n%8s%10.1e\n\n",
              "Estimate of error bound for computed solutions", "", errbnd);
    }
  else if (fail.code == NE_RCOND)
    {
      /* Matrix A is numerically singular.  Print estimate of */
      /* reciprocal of condition number and solution */

      printf("\n");
      printf("%s\n%8s%10.1e\n\n\n",
              "Estimate of reciprocal of condition number", "", rcond);
      /* nag_gen_complx_mat_print_comp (x04dbc), see above. */
      fflush(stdout);
      nag_gen_complx_mat_print_comp(order, Nag_GeneralMatrix, Nag_NonUnitDiag,
                                    n, nrhs, b, pdb, Nag_BracketForm, 0,
                                    "Solution", Nag_IntegerLabels, 0,
                                    Nag_IntegerLabels, 0, 80, 0, 0,
                                    &fail);
      if (fail.code != NE_NOERROR)
        {
          printf(
                  "Error from nag_gen_complx_mat_print_comp (x04dbc).\n%s\n",
                  fail.message);
          exit_status = 1;
          goto END;
        }
    }
  else if (fail.code == NE_SINGULAR)
    {
      /* The upper triangular matrix U is exactly singular.  Print */
      /* details of factorization */

      printf("%s\n\n", "Details of factorization");
      printf("%s", " Second super-diagonal of U");
      printf("\n");

      for (i = 1; i <= n - 2; ++i)
        {
          printf("(%7.4f, %7.4f)%s", du2[i - 1].re,
                  du2[i - 1].im, i%4 == 0 || i == n - 2?"\n":" ");
        }

      printf("\n\n");

      printf("%s\n", " First super-diagonal of U");


      for (i = 1; i <= n - 1; ++i)
        {
          printf("(%7.4f, %7.4f)%s", du[i - 1].re, du[i - 1].im,
                  i%4 == 0 || i == n - 1?"\n":" ");
        }

      printf("\n\n");
      printf("%s\n", " Main diagonal of U");

      for (i = 1; i <= n; ++i)
        {
          printf("(%7.4f, %7.4f)%s", d[i - 1].re, d[i - 1].im,
                  i%4 == 0 || i == n?"\n":" ");
        }
      printf("\n\n");
      printf("%s\n", " Multipliers");

      for (i = 1; i <= n - 1; ++i)
        {
          printf("(%7.4f, %7.4f)%s", dl[i - 1].re, dl[i - 1].im,
                  i%4 == 0 || i == n - 1?"\n":" ");
        }
      printf("\n\n");
      printf("%s\n", " Vector of interchanges");

      for (i = 1; i <= n; ++i)
        {
          printf("%9ld%s", ipiv[i - 1], i%8 == 0 || i == n?"\n":" ");
        }
      printf("\n");
    }
  else
    {
      printf(
              "Error from nag_complex_tridiag_lin_solve (f04ccc).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }
 END:
  if (clabs) NAG_FREE(clabs);
  if (rlabs) NAG_FREE(rlabs);
  if (b) NAG_FREE(b);
  if (d) NAG_FREE(d);
  if (dl) NAG_FREE(dl);
  if (du) NAG_FREE(du);
  if (du2) NAG_FREE(du2);
  if (ipiv) NAG_FREE(ipiv);


  return exit_status;
}

#undef B