/* nag_sparse_sym_chol_fac (f11jac) Example Program.
 *
 * Copyright 1998 Numerical Algorithms Group.
 *
 * Mark 5, 1998.
 *
 */

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

int main(void)
{
  double dtol;
  double *a;
  double dscale;

  Integer *irow, *icol;
  Integer *ipiv, nnzc, *istr;
  Integer i, n, lfill, npivm;
  Integer nnz;
  Integer num;

  Nag_SparseSym_Piv pstrat;
  Nag_SparseSym_Fact mic;
  Nag_Sparse_Comm comm;

  char char_enum[20];

  Vprintf("f11jac Example Program Results\n\n");

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

  /* Read algorithmic parameters */
  Vscanf("%ld",&n);
  Vscanf("%*[^\n]");
  Vscanf("%ld%*[^\n]",&nnz);
  Vscanf("%ld%lf%*[^\n]", &lfill, &dtol);
  Vscanf("%s%lf%*[^\n]",char_enum, &dscale);

  if (!strcmp(char_enum, "ModFact"))
    mic = Nag_SparseSym_ModFact;
  else if (!strcmp(char_enum, "UnModFact"))
    mic = Nag_SparseSym_UnModFact;
  else
    {
      Vprintf("Unrecognised string for mic enum representation.\n");
      return EXIT_FAILURE;
    }

  Vscanf("%s%*[^\n]",char_enum);
  if (!strcmp(char_enum, "NoPiv"))
    pstrat = Nag_SparseSym_NoPiv;
  else if (!strcmp(char_enum, "MarkPiv"))
    pstrat = Nag_SparseSym_MarkPiv;
  else if (!strcmp(char_enum, "UserPiv"))
    pstrat = Nag_SparseSym_UserPiv;
  else
    {
      Vprintf("Unrecognised string for pstrat enum representation.\n");
      return EXIT_FAILURE;
    }

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

  if (!ipiv || !istr || !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 Cholesky factorization */

  f11jac(n, nnz, &a, &num, &irow, &icol, lfill, dtol, mic,
         dscale, pstrat, ipiv, istr, &nnzc, &npivm, &comm, NAGERR_DEFAULT);

  /* Output original matrix */

  Vprintf(" Original Matrix \n");
  Vprintf(" n     = %6ld\n",n);
  Vprintf(" nnz   = %6ld\n\n",nnz);
  for (i = 1; i <= nnz; ++i)
    Vprintf(" %8ld%16.4e%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 nnz = %6ld\n",n,nnzc);
  Vprintf(" npivm = %6ld\n\n",npivm);
  for (i = nnz + 1; i <= nnz + nnzc; ++i)
    Vprintf(" %8ld%16.4e%8ld%8ld\n",i,a[i-1],irow[i-1],icol[i-1]);

  Vprintf("\n        i     ipiv(i) \n");
  for (i = 1; i <= n; ++i)
    Vprintf(" %8ld%8ld\n",i,ipiv[i-1]);

  NAG_FREE(irow);
  NAG_FREE(icol);
  NAG_FREE(a);
  NAG_FREE(istr);
  NAG_FREE(ipiv);
  return EXIT_SUCCESS;
}