/* nag_zgerfs (f07avc) Example Program.
 *
 * Copyright 2001 Numerical Algorithms Group.
 *
 * Mark 7, 2001.
 */

#include <stdio.h>
#include <nag.h>
#include <nag_stdlib.h>
#include <nagf07.h>
#include <nagx04.h>

int main(int argc, char *argv[])
{
  FILE          *fpin, *fpout;
  char          *outfile = 0;
  /* Scalars */
  Integer       berr_len, i, ferr_len, ipiv_len, j, n, nrhs;
  Integer       pda, pdaf, pdb, pdx;
  Integer       exit_status = 0;
  NagError      fail;
  Nag_OrderType order;
  /* Arrays */
  Complex       *a = 0, *af = 0, *b = 0, *x = 0;
  double        *berr = 0, *ferr = 0;
  Integer       *ipiv = 0;

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

  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_zgerfs (f07avc) Example Program Results\n\n");

  /* Skip heading in data file */
  fscanf(fpin, "%*[^\n] ");
  fscanf(fpin, "%ld%ld%*[^\n] ", &n, &nrhs);
#ifdef NAG_COLUMN_MAJOR
  pda = n;
  pdaf = n;
  pdb = n;
  pdx = n;
#else
  pda = n;
  pdaf = n;
  pdb = nrhs;
  pdx = nrhs;
#endif
  ipiv_len = n;
  ferr_len = n;
  berr_len = nrhs;

  /* Allocate memory */
  if (!(a = NAG_ALLOC(n * n, Complex)) ||
      !(af = NAG_ALLOC(n * n, Complex)) ||
      !(b = NAG_ALLOC(n * nrhs, Complex)) ||
      !(x = NAG_ALLOC(n * n, Complex)) ||
      !(berr = NAG_ALLOC(berr_len, double)) ||
      !(ferr = NAG_ALLOC(ferr_len, double)) ||
      !(ipiv = NAG_ALLOC(ipiv_len, Integer)))
    {
      fprintf(fpout, "Allocation failure\n");
      exit_status = -1;
      goto END;
    }

  /* Read A and B from data file, and copy A to AF and B to X */
  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] ");

  for (i = 1; i <= n; ++i)
    {
      for (j = 1; j <= n; ++j)
        {
          AF(i, j).re = A(i, j).re;
          AF(i, j).im = A(i, j).im;
        }
    }
  for (i = 1; i <= n; ++i)
    {
      for (j = 1; j <= nrhs; ++j)
        {
          X(i, j).re = B(i, j).re;
          X(i, j).im = B(i, j).im;
        }
    }
  /* Factorize A in the array AF */
  /* nag_zgetrf (f07arc).
   * LU factorization of complex m by n matrix
   */
  nag_zgetrf(order, n, n, af, pdaf, ipiv, &fail);
  if (fail.code != NE_NOERROR)
    {
      fprintf(fpout, "Error from nag_zgetrf (f07arc).\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }
  /* Compute solution in the array X */
  /* nag_zgetrs (f07asc).
   * Solution of complex system of linear equations, multiple
   * right-hand sides, matrix already factorized by nag_zgetrf
   * (f07arc)
   */
  nag_zgetrs(order, Nag_NoTrans, n, nrhs, af, pdaf, ipiv, x, pdx, &fail);
  if (fail.code != NE_NOERROR)
    {
      fprintf(fpout, "Error from nag_zgetrs (f07asc).\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }
  /* Improve solution, and compute backward errors and */
  /* estimated bounds on the forward errors */
  /* nag_zgerfs (f07avc).
   * Refined solution with error bounds of complex system of
   * linear equations, multiple right-hand sides
   */
  nag_zgerfs(order, Nag_NoTrans, n, nrhs, a, pda, af, pdaf, ipiv, b, pdb, x,
             pdx, ferr, berr, &fail);
  if (fail.code != NE_NOERROR)
    {
      fprintf(fpout, "Error from nag_zgerfs (f07avc).\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }

  /* Print solution */
  /* 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, x, pdx, Nag_BracketForm, "%7.4f",
                                "Solution(s)", 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, "\nBackward errors (machine-dependent)\n");

  for (j = 1; j <= nrhs; ++j)
    fprintf(fpout, "%11.1e%s", berr[j-1], j%4 == 0?"\n":" ");
  fprintf(fpout, "\nEstimated forward error bounds (machine-dependent)\n");
  for (j = 1; j <= nrhs; ++j)
    fprintf(fpout, "%11.1e%s", ferr[j-1], j%4 == 0 || j == nrhs?"\n":" ");
 END:
  if (fpin != stdin) fclose(fpin);
  if (fpout != stdout) fclose(fpout);
  if (a) NAG_FREE(a);
  if (af) NAG_FREE(af);
  if (b) NAG_FREE(b);
  if (x) NAG_FREE(x);
  if (berr) NAG_FREE(berr);
  if (ferr) NAG_FREE(ferr);
  if (ipiv) NAG_FREE(ipiv);
  return exit_status;
}