/* nag_complex_gen_lin_solve (f04cac) 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(int argc, char *argv[])
{
  FILE          *fpin, *fpout;
  char          *outfile = 0;
  /* Scalars */
  double        errbnd, rcond;
  Integer       exit_status, i, j, n, nrhs, pda, pdb;

  /* Arrays */
  char          *clabs = 0, *rlabs = 0;
  Complex       *a = 0, *b = 0;
  Integer       *ipiv = 0;

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

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

  exit_status = 0;
  INIT_FAIL(fail);

  /* Check for command-line IO options */
  fpin = nag_example_file_io(argc, argv, "-data", NULL);
  fpout = nag_example_file_io(argc, argv, "-results", NULL);
  (void) nag_example_file_io(argc, argv, "-nag_write", &outfile);

  fprintf(fpout,
          "nag_complex_gen_lin_solve (f04cac) Example Program Results\n\n");

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

  fscanf(fpin, "%ld%ld%*[^\n] ", &n, &nrhs);
  if (n > 0 && nrhs > 0)
    {
      /* Allocate memory */
      if (!(clabs = NAG_ALLOC(2, char)) ||
          !(rlabs = NAG_ALLOC(2, char)) ||
          !(a = NAG_ALLOC(n*n, Complex)) ||
          !(b = NAG_ALLOC(n*nrhs, Complex)) ||
          !(ipiv = NAG_ALLOC(8, Integer)))
        {
          fprintf(fpout, "Allocation failure\n");
          exit_status = -1;
          goto END;
        }
#ifdef NAG_COLUMN_MAJOR
      pda = n;
      pdb = n;
#else
      pda = n;
      pdb = nrhs;
#endif

      /* Read A and B from data file */
    }
  else
    {
      fprintf(fpout, "%s\n", "NMAX and/or NRHSMX too small");
      exit_status = 1;
      return exit_status;
    }

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

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


  /* Solve the equations AX = B for X */
  /* nag_complex_gen_lin_solve (f04cac).
   * Computes the solution and error-bound to a complex system
   * of linear equations
   */
  nag_complex_gen_lin_solve(order, n, nrhs, a, pda, 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)
       */
      if (outfile) fclose(fpout);
      nag_gen_complx_mat_print_comp(order, Nag_GeneralMatrix, Nag_NonUnitDiag,
                                    n, nrhs, b, pdb, Nag_BracketForm, "%7.4f",
                                    "Solution", Nag_IntegerLabels, 0,
                                    Nag_IntegerLabels, 0, 80, 0, outfile,
                                    &fail);
      if (outfile && !(fpout = fopen(outfile, "a")))
        {
          exit_status = 2;
          goto END;
        }
      if (fail.code != NE_NOERROR)
        {
          fprintf(fpout,
                  "Error from nag_gen_complx_mat_print_comp (x04dbc).\n%s\n",
                  fail.message);
          exit_status = 1;
          goto END;
        }

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

      fprintf(fpout, "\n");
      fprintf(fpout, "%s\n%8s%10.1e\n\n\n",
              "Estimate of reciprocal of condition number", "", rcond);
      /* nag_gen_complx_mat_print_comp (x04dbc), see above. */
      if (outfile) fclose(fpout);
      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, outfile,
                                    &fail);
      if (outfile && !(fpout = fopen(outfile, "a")))
        {
          exit_status = 2;
          goto END;
        }
      if (fail.code != NE_NOERROR)
        {
          fprintf(fpout,
                  "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 triangualr matrix U is exactly singular.  Print */
      /* details of factorization */
      fprintf(fpout, "\n");
      /* nag_gen_complx_mat_print_comp (x04dbc), see above. */
      if (outfile) fclose(fpout);
      nag_gen_complx_mat_print_comp(order, Nag_GeneralMatrix, Nag_NonUnitDiag,
                                    n, n, a, pda, Nag_BracketForm, "%7.4f",
                                    "Details of factorization",
                                    Nag_IntegerLabels, 0, Nag_IntegerLabels, 0,
                                    80, 0, outfile, &fail);
      if (outfile && !(fpout = fopen(outfile, "a")))
        {
          exit_status = 2;
          goto END;
        }
      if (fail.code != NE_NOERROR)
        {
          fprintf(fpout,
                  "Error from nag_gen_complx_mat_print_comp (x04dbc).\n%s\n",
                  fail.message);
          exit_status = 1;
          goto END;
        }

      /* Print pivot indices */
      fprintf(fpout, "\n");
      fprintf(fpout, "%s\n", "Pivot indices");
      fprintf(fpout, "%1s", "");
      for (i = 1; i <= n; ++i)
        {
          fprintf(fpout, "%11ld%s", ipiv[i - 1], i%7 == 0 || i == n?"\n":" ");
        }
      fprintf(fpout, "\n");
    }
  else
    {
      fprintf(fpout, "Error from nag_complex_gen_lin_solve (f04cac).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }
 END:
  if (fpin != stdin) fclose(fpin);
  if (fpout != stdout) fclose(fpout);
  if (clabs) NAG_FREE(clabs);
  if (rlabs) NAG_FREE(rlabs);
  if (a) NAG_FREE(a);
  if (b) NAG_FREE(b);
  if (ipiv) NAG_FREE(ipiv);

  return exit_status;
}