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

#include <stdio.h>
#include <nag.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[])
{
  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);
  exit_status = 0;

  Vprintf(" nag_mesh2d_renum (d06ccc) Example Program Results\n\n");

  /* Skip heading in data file */

  Vscanf("%*[^\n] ");

  /* Reading of the geometry */

  Vscanf("%ld", &nv);
  Vscanf("%ld", &nelt);
  Vscanf("%ld", &nedge);
  Vscanf("%*[^\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)) )
    {
      Vprintf("Allocation failure\n");
      exit_status = -1;
      goto END;
    }

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

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

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

  Vscanf(" ' %1s '", pmesh);
  Vscanf("%*[^\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')
        {
          Vprintf(" The Matrix Sparsity characteristics\n");
          Vprintf(" before the renumbering\n");
          Vprintf(" nv  =%6ld\n", nv);
          Vprintf(" nnz =%6ld\n", nnz);
        }
      else if (pmesh[0] == 'Y')
        {
          /* Output the sparsity of the mesh to view */
          /* it using the NAG Graphics Library */

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

          for (i = 0; i < nnz; ++i)
            Vprintf(" %10ld%10ld\n", irow[i], icol[i]);
        }
      else
        {
          Vprintf("Problem with the printing option Y or N\n");
          exit_status = -1;
          goto END;
        }
    }
  else
    {
      Vprintf("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
   */
  nag_mesh2d_renum(nv, nelt, nedge, nnzmax, &nnz, coor, edge, conn, irow, icol,
                   itrace, 0, &fail);

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

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

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

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

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

          for (i = 1; i <= nv; ++i)
            Vprintf("  %12.6e  %12.6e  \n",
                    COOR(1,i), COOR(2,i));

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

 END:
  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;
}