/* nag_mesh2d_renum (d06ccc) Example Program.
 *
 * Copyright 2001 Numerical Algorithms Group.
 *
 * Mark 7, 2001.
 */

#include <stdio.h>
#include <nag.h>
#include <nagx04.h>
#include <nag_stdlib.h>
#include <nagd06.h>

#define EDGE(I, J) edge[3*((J) -1)+(I) -1]
#define CONN(I, J) conn[3*((J) -1)+(I) -1]
#define COOR(I, J) coor[2*((J) -1)+(I) -1]

int main(int argc, char *argv[])
{
  FILE     *fpin, *fpout;
  char     *outfile = 0;
  Integer  exit_status, i, itrace, nedge, nelt, nnz, nnzmax, nv, reftk;
  NagError fail;
  char     pmesh[2];
  double   *coor = 0;
  Integer  *conn = 0, *edge = 0, *icol = 0, *irow = 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);
  exit_status = 0;

  fprintf(fpout, " nag_mesh2d_renum (d06ccc) Example Program Results\n\n");

  /* Skip heading in data file */

  fscanf(fpin, "%*[^\n] ");

  /* Reading of the geometry */

  fscanf(fpin, "%ld", &nv);
  fscanf(fpin, "%ld", &nelt);
  fscanf(fpin, "%ld", &nedge);
  fscanf(fpin, "%*[^\n] ");

  nnzmax = 10*nv;

  /* Allocate memory */

  if (!(coor = NAG_ALLOC(2*nv, double)) ||
      !(conn = NAG_ALLOC(3*nelt, Integer)) ||
      !(edge = NAG_ALLOC(3*nedge, Integer)) ||
      !(irow = NAG_ALLOC(nnzmax, Integer)) ||
      !(icol = NAG_ALLOC(nnzmax, Integer)))
    {
      fprintf(fpout, "Allocation failure\n");
      exit_status = -1;
      goto END;
    }

  for (i = 1; i <= nv; ++i)
    {
      fscanf(fpin, "%lf", &COOR(1, i));
      fscanf(fpin, "%lf", &COOR(2, i));
      fscanf(fpin, "%*[^\n] ");
    }

  for (i = 1; i <= nelt; ++i)
    {
      fscanf(fpin, "%ld", &CONN(1, i));
      fscanf(fpin, "%ld", &CONN(2, i));
      fscanf(fpin, "%ld", &CONN(3, i));
      fscanf(fpin, "%ld", &reftk);
      fscanf(fpin, "%*[^\n] ");
    }

  for (i = 1; i <= nedge; ++i)
    {
      fscanf(fpin, "%ld", &reftk);
      fscanf(fpin, "%ld", &EDGE(1, i));
      fscanf(fpin, "%ld", &EDGE(2, i));
      fscanf(fpin, "%ld", &EDGE(3, i));
      fscanf(fpin, "%*[^\n] ");
    }

  fscanf(fpin, " ' %1s '", pmesh);
  fscanf(fpin, "%*[^\n] ");

  /* Compute the sparsity of the FE matrix */
  /* from the input geometry */

  /* nag_mesh2d_sparse (d06cbc).
   * Generates a sparsity pattern of a Finite Element matrix
   * associated with a given mesh
   */
  nag_mesh2d_sparse(nv, nelt, nnzmax, conn, &nnz, irow, icol, &fail);

  if (fail.code == NE_NOERROR)
    {
      if (pmesh[0] == 'N')
        {
          fprintf(fpout, " The Matrix Sparsity characteristics\n");
          fprintf(fpout, " before the renumbering\n");
          fprintf(fpout, " nv  =%6ld\n", nv);
          fprintf(fpout, " nnz =%6ld\n", nnz);
        }
      else if (pmesh[0] == 'Y')
        {
          /* Output the sparsity of the mesh to view */
          /* it using the NAG Graphics Library */

          fprintf(fpout, " %10ld%10ld\n", nv, nnz);

          for (i = 0; i < nnz; ++i)
            fprintf(fpout, " %10ld%10ld\n", irow[i], icol[i]);
        }
      else
        {
          fprintf(fpout, "Problem with the printing option Y or N\n");
          exit_status = -1;
          goto END;
        }
    }
  else
    {
      fprintf(fpout, "Error from nag_mesh2d_sparse (d06cbc).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }

  /* Call the renumbering routine and get the new sparsity */

  itrace = 1;

  /* nag_mesh2d_renum (d06ccc).
   * Renumbers a given mesh using Gibbs method
   */
  if (outfile) fclose(fpout);
  nag_mesh2d_renum(nv, nelt, nedge, nnzmax, &nnz, coor, edge, conn, irow, icol,
                   itrace, outfile, &fail);
  if (outfile && !(fpout = fopen(outfile, "a")))
    {
      exit_status = 2;
      goto END;
    }
  if (fail.code == NE_NOERROR)
    {
      if (pmesh[0] == 'N')
        {
          fprintf(fpout, "\n The Matrix Sparsity characteristics\n");
          fprintf(fpout, " after the renumbering\n");
          fprintf(fpout, " nv   =%6ld\n", nv);
          fprintf(fpout, " nnz  =%6ld\n", nnz);
          fprintf(fpout, " nelt =%6ld\n", nelt);
        }
      else if (pmesh[0] == 'Y')
        {
          /* Output the sparsity of the renumbered mesh */
          /* to view it using the NAG Graphics Library */

          fprintf(fpout, "%10ld%10ld\n", nv, nnz);

          for (i = 0; i < nnz; ++i)
            fprintf(fpout, " %10ld%10ld\n", irow[i], icol[i]);

          /* Output the renumbered mesh to view */
          /* it using the NAG Graphics Library */

          fprintf(fpout, " %10ld%10ld\n", nv, nelt);

          for (i = 1; i <= nv; ++i)
            fprintf(fpout, "  %15.6e  %15.6e  \n",
                    COOR(1, i), COOR(2, i));

          reftk = 0;
          for (i = 1; i <= nelt; ++i)
            fprintf(fpout, " %10ld%10ld%10ld%10ld\n",
                    CONN(1, i), CONN(2, i), CONN(3, i), reftk);
        }
    }
  else
    {
      fprintf(fpout, "Error from nag_mesh2d_renum (d06ccc).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }

 END:
  if (fpin != stdin) fclose(fpin);
  if (fpout != stdout) fclose(fpout);
  if (coor) NAG_FREE(coor);
  if (conn) NAG_FREE(conn);
  if (edge) NAG_FREE(edge);
  if (irow) NAG_FREE(irow);
  if (icol) NAG_FREE(icol);

  return exit_status;
}