/* nag_sparse_nsym_fac (f11dac) Example Program.
 *
 * Copyright 1998 Numerical Algorithms Group.
 *
 * Mark 5, 1998.
 */

#include <nag.h>
#include <nag_stdlib.h>
#include <nag_string.h>
#include <stdio.h>
#include <nagf11.h>

int main(void)
{
  double dtol;
  double *a=0;

  Integer *icol=0, *irow=0, *istr=0, *idiag=0, *ipivp=0, *ipivq=0;
  Integer nnzc ;
  Integer i, n, lfill, npivm;
  Integer nnz;
  Integer num;

  Nag_SparseNsym_Fact milu;
  Nag_SparseNsym_Piv pstrat;

  char char_enum[20];

  Vprintf("nag_sparse_nsym_fac (f11dac) Example Program Results\n");
  /* Skip heading in data file */
  Vscanf("%*[^\n]");

  Vscanf("%ld%*[^\n]",&n);
  Vscanf("%ld%*[^\n]",&nnz);
  Vscanf("%ld%lf%*[^\n]",&lfill, &dtol);

  Vscanf("%s%*[^\n]", char_enum);
  if (!strcmp(char_enum, "NoPiv"))
    pstrat = Nag_SparseNsym_NoPiv;
  else if (!strcmp(char_enum, "UserPiv"))
    pstrat = Nag_SparseNsym_UserPiv;
  else if (!strcmp(char_enum, "PartialPiv"))
    pstrat = Nag_SparseNsym_PartialPiv;
  else if (!strcmp(char_enum, "CompletePiv"))
    pstrat = Nag_SparseNsym_CompletePiv;
  else
    {
      Vprintf("Unrecognised string for pstrat enum representation.\n");
      return EXIT_FAILURE;
    }

  Vscanf("%s%*[^\n]", char_enum);
  if (!strcmp(char_enum, "ModFact"))
    milu = Nag_SparseNsym_ModFact;
  else if (!strcmp(char_enum, "UnModFact"))
    milu = Nag_SparseNsym_UnModFact;
  else
    {
      Vprintf("Unrecognised string for method enum representation.\n");
      return EXIT_FAILURE;
    }

  num = 2*nnz;
  istr = NAG_ALLOC(n+1, Integer);
  idiag = NAG_ALLOC(n, Integer);
  ipivp = NAG_ALLOC(n, Integer);
  ipivq = NAG_ALLOC(n, Integer);
  irow = NAG_ALLOC(num,Integer);
  icol = NAG_ALLOC(num,Integer);
  a = NAG_ALLOC(num,double);

  if (!istr || !idiag || !ipivp || !ipivq || !irow || !icol || !a)
    {
      Vprintf("Allocation failure\n");
      return EXIT_FAILURE;
    }

  /* Read the matrix a */

  for (i = 1; i <= nnz; ++i)
    Vscanf("%lf%ld%ld%*[^\n]",&a[i-1], &irow[i-1],&icol[i-1]);

  /* Calculate incomplete LU factorization */

  /* nag_sparse_nsym_fac (f11dac).
   * Incomplete LU factorization (nonsymmetric)
   */
  nag_sparse_nsym_fac(n, nnz, &a, &num, &irow, &icol, lfill, dtol, pstrat, milu,
                      ipivp, ipivq, istr, idiag, &nnzc, &npivm, NAGERR_DEFAULT);

  /* Output original matrix */

  Vprintf("  Original Matrix \n  n     = %6ld\n",n);
  Vprintf("  nnz   = %6ld\n",nnz);

  for (i = 1; i <= nnz; ++i)
    Vprintf("%8ld%16.6e%8ld%8ld\n", i, a[i-1],
            irow[i-1], icol[i-1]);
  Vprintf("\n");

  /* Output details of the factorization */

  Vprintf("  Factorization \n  n     = %6ld\n",n);
  Vprintf("  nnz   = %6ld\n",nnzc);
  Vprintf("  npivm = %6ld\n",npivm);

  for (i = nnz + 1; i <= nnz + nnzc; ++i)
    Vprintf("%8ld%16.6e%8ld%8ld\n", i, a[i-1],
            irow[i-1], icol[i-1]);

  Vprintf("\n         i       ipivp[i-1]  ipivq[i-1] \n"); /* */

  for (i = 1; i <= n; ++i)
    Vprintf("%10ld%10ld%10ld\n", i, ipivp[i-1],
            ipivq[i-1]);

  NAG_FREE(istr);
  NAG_FREE(idiag);
  NAG_FREE(ipivp);
  NAG_FREE(ipivq);
  NAG_FREE(irow);
  NAG_FREE(icol);
  NAG_FREE(a);
  return EXIT_SUCCESS;

}