/* nag_superlu_solve_lu (f11mfc) Example Program.
 *
 * Copyright 2005 Numerical Algorithms Group.
 *
 * Mark 8, 2005.
 */

#include <stdio.h>
#include <nag.h>
#include <nagx04.h>
#include <nag_stdlib.h>
#include <nagf11.h>


int main(int argc, char *argv[])
{
  FILE                      *fpin, *fpout;
  char                      *outfile = 0;
  double                    flop, thresh;
  Integer                   exit_status = 0, i, j;
  Integer                   n, nnz, nnzl, nnzu, nrhs, nzlmx, nzlumx, nzumx;
  double                    *a = 0, *lval = 0, *uval = 0, *x = 0;
  Integer                   *icolzp = 0, *il = 0, *iprm = 0, *irowix = 0;
  Integer                   *iu = 0;
  /* Nag types */
  Nag_OrderType             order = Nag_ColMajor;
  Nag_MatrixType            matrix = Nag_GeneralMatrix;
  Nag_DiagType              diag = Nag_NonUnitDiag;
  Nag_ColumnPermutationType ispec;
  Nag_TransType             trans;
  NagError                  fail;

  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);
  fprintf(fpout, "nag_superlu_solve_lu (f11mfc) Example Program Results\n\n");
  /* Skip heading in data file */
  fscanf(fpin, "%*[^\n] ");
  /* Read order of matrix and number of right hand sides */
  fscanf(fpin, "%ld%ld%*[^\n] ", &n, &nrhs);
  /* Read the matrix A */
  if (!(icolzp = NAG_ALLOC(n+1, Integer)))
    {
      fprintf(fpout, "Allocation failure\n");
      exit_status = -1;
      goto END;
    }
  for (i = 1; i <= n + 1; ++i)
    {
      fscanf(fpin, "%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)) ||
      !(x = NAG_ALLOC(n*nrhs, double)))
    {
      fprintf(fpout, "Allocation failure\n");
      exit_status = -1;
      goto END;
    }
  for (i = 1; i <= nnz; ++i)
    fscanf(fpin, "%lf%ld%*[^\n] ", &a[i - 1], &irowix[i - 1]);
  /* Read the right hand sides */
  for (j = 1; j <= nrhs; ++j)
    {
      for (i = 1; i <= n; ++i)
        fscanf(fpin, "%lf", &x[j*n + i - n - 1]);
      fscanf(fpin, "%*[^\n] ");
    }
  /* 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)
    {
      fprintf(fpout,
              "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)
    {
      fprintf(fpout, "Error from nag_superlu_lu_factorize (f11mec).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }
  /* Solve */
  trans = Nag_NoTrans;
  /* nag_superlu_solve_lu (f11mfc).
   * Solution of real sparse simultaneous linear equations
   * (coefficient matrix already factorized)
   */
  nag_superlu_solve_lu(order, trans, n, iprm, il, lval, iu, uval, nrhs, x,
                       n, &fail);
  if (fail.code != NE_NOERROR)
    {
      fprintf(fpout, "Error from nag_superlu_solve_lu (f11mfc).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }
  /* Output results */
  fprintf(fpout, "\n");
  /* nag_gen_real_mat_print (x04cac).
   * Print real general matrix (easy-to-use)
   */
  if (outfile) fclose(fpout);
  nag_gen_real_mat_print(order, matrix, diag, n, nrhs,
                         x, n, "Solutions", outfile, &fail);
  if (outfile && !(fpout = fopen(outfile, "a")))
    {
      exit_status = 2;
      goto END;
    }
  if (fail.code != NE_NOERROR)
    {
      fprintf(fpout, "Error from nag_gen_real_mat_print (x04cac).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }

 END:
  if (fpin != stdin) fclose(fpin);
  if (fpout != stdout) fclose(fpout);
  if (a) NAG_FREE(a);
  if (lval) NAG_FREE(lval);
  if (uval) NAG_FREE(uval);
  if (x) NAG_FREE(x);
  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;
}