/* nag_superlu_condition_number_lu (f11mgc) Example Program.
 *
 * Copyright 2005 Numerical Algorithms Group.
 *
 * Mark 8, 2005.
 */

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

int main(void)
{
  double d__1;
  double anorm, flop, rcond, thresh;
  Integer exit_status=0, i, n, nnz, nnzl, nnzu, nzlmx, nzlumx, nzumx;
  double *a=0, *lval=0, *uval=0;
  Integer *icolzp=0, *il=0, *iprm=0, *irowix=0, *iu=0;
  /* Nag types */
  NagError fail;
  Nag_ColumnPermutationType ispec;
  Nag_NormType norm;


  INIT_FAIL(fail);
  Vprintf( "nag_superlu_condition_number_lu (f11mgc) Example Program Results"
           "\n\n");
  /* Skip heading in data file */
  Vscanf("%*[^\n] ");
  /* Read order of matrix */
  Vscanf("%ld%*[^\n] ",   &n);
  /* Read the matrix A */
  if ( !(icolzp = NAG_ALLOC(n+1, Integer)))
    {
      Vprintf("Allocation failure\n");
      exit_status = -1;
      goto END;
    }
  for (i = 1; i <= n + 1; ++i)
    Vscanf("%ld%*[^\n] ", &icolzp[i - 1]);
  nnz = icolzp[n] - 1;
  /* Allocate memory */
  if ( !(irowix = NAG_ALLOC(nnz, Integer)) ||
       !(a = NAG_ALLOC(nnz, double)) ||
       !(il = NAG_ALLOC(7*n+8*nnz+4, Integer)) ||
       !(iu = NAG_ALLOC(2*n+8*nnz+1, Integer)) ||
       !(uval = NAG_ALLOC(8*nnz, double)) ||
       !(lval = NAG_ALLOC(8*nnz, double)) ||
       !(iprm = NAG_ALLOC(7*n, Integer)) )
    {
      Vprintf("Allocation failure\n");
      exit_status = -1;
      goto END;
    }
  for (i = 1; i <= nnz; ++i)
    Vscanf("%lf%ld%*[^\n] ",   &a[i - 1],  &irowix[i - 1]);

  /* Calculate COLAMD permutation */
  ispec = Nag_Sparse_Colamd;
  /* nag_superlu_column_permutation (f11mdc).
   * Real sparse nonsymmetric linear systems, setup for
   * nag_superlu_lu_factorize (f11mec)
   */
  nag_superlu_column_permutation(ispec, n, icolzp, irowix, iprm, &fail);
  if (fail.code != NE_NOERROR)
    {
      Vprintf("Error from nag_superlu_column_permutation (f11mdc).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }

  /* Factorise */
  thresh = 1.;
  nzlmx = 8*nnz;
  nzlumx = 8*nnz;
  nzumx = 8*nnz;
  /* nag_superlu_lu_factorize (f11mec).
   * LU factorization of real sparse matrix
   */
  nag_superlu_lu_factorize(n, irowix, a, iprm, thresh, nzlmx, &nzlumx, nzumx,
                           il, lval, iu, uval, &nnzl, &nnzu, &flop, &fail);
  if (fail.code != NE_NOERROR)
    {
      Vprintf("Error from nag_superlu_lu_factorize (f11mec).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }

  /* Calculate norm */
  norm = Nag_RealOneNorm;
  /* nag_superlu_matrix_norm (f11mlc).
   * 1-norm, infinity-norm, largest absolute element, real
   * general matrix
   */
  nag_superlu_matrix_norm(norm, &anorm, n, icolzp, irowix, a, &fail);
  if (fail.code != NE_NOERROR)
    {
      Vprintf("Error from nag_superlu_matrix_norm (f11mlc).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }

  /* Calculate condition number */
  /* nag_superlu_condition_number_lu (f11mgc).
   * Estimate condition number of real matrix, matrix already
   * factorized by nag_superlu_lu_factorize (f11mec)
   */
  nag_superlu_condition_number_lu(norm, n, il, lval, iu, uval, anorm, &rcond,
                                  &fail);
  if (fail.code != NE_NOERROR)
    {
      Vprintf("Error from nag_superlu_condition_number_lu (f11mgc).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }

  /* Output result */
  d__1 = 1 / rcond;
  Vprintf("\n%s\n %7.3f,%7.3f\n",   "   Norm,  Condition number",
          anorm,  d__1);
  Vprintf("\n");

 END:
  if (a) NAG_FREE(a);
  if (lval) NAG_FREE(lval);
  if (uval) NAG_FREE(uval);
  if (icolzp) NAG_FREE(icolzp);
  if (il) NAG_FREE(il);
  if (iprm) NAG_FREE(iprm);
  if (irowix) NAG_FREE(irowix);
  if (iu) NAG_FREE(iu);

  return exit_status;
}