/* nag_dpotrf (f07fdc) Example Program.
 *
 * Copyright 2001 Numerical Algorithms Group.
 *
 * Mark 7, 2001.
 */

#include <stdio.h>
#include <nag.h>
#include <nag_stdlib.h>
#include <nagf07.h>
#include <nagx04.h>

int main(void)
{
  /* Scalars */
  Integer i, j, n, pda;
  Integer exit_status=0;
  Nag_UploType uplo_enum;
  Nag_MatrixType matrix;

  NagError fail;
  Nag_OrderType order;
  /* Arrays */
  char   uplo[2];
  double *a=0;

#ifdef NAG_COLUMN_MAJOR
#define A(I,J) a[(J-1)*pda + I - 1]
  order = Nag_ColMajor;
#else
#define A(I,J) a[(I-1)*pda + J - 1]
  order = Nag_RowMajor;
#endif

  INIT_FAIL(fail);
  Vprintf("f07fdc Example Program Results\n\n");

  /* Skip heading in data file */
  Vscanf("%*[^\n] ");
  Vscanf("%ld%*[^\n] ", &n);
#ifdef NAG_COLUMN_MAJOR
  pda = n;
#else
  pda = n;
#endif
  /* Allocate memory */
  if ( !(a = NAG_ALLOC(n * n, double)) )
    {
      Vprintf("Allocation failure\n");
      exit_status = -1;
      goto END;
    }


  /* Read A from data file */
  Vscanf(" ' %1s '%*[^\n] ", uplo);
 if (*(unsigned char *)uplo == 'L')
   {
     uplo_enum = Nag_Lower;
     matrix = Nag_LowerMatrix;
   }
 else if (*(unsigned char *)uplo == 'U')
   {
     uplo_enum = Nag_Upper;
     matrix = Nag_UpperMatrix;
   }
 else
   {
     Vprintf("Unrecognised character for Nag_UploType type\n");
     exit_status = -1;
     goto END;
   }
  if (uplo_enum == Nag_Upper)
    {
      for (i = 1; i <= n; ++i)
        {
          for (j = i; j <= n; ++j)
            Vscanf("%lf", &A(i,j));
        }
      Vscanf("%*[^\n] ");
    }
  else
    {
      for (i = 1; i <= n; ++i)
        {
          for (j = 1; j <= i; ++j)
            Vscanf("%lf", &A(i,j));
        }
      Vscanf("%*[^\n] ");
    }

  /* Factorize A */
  f07fdc(order, uplo_enum, n, a, pda, &fail);
  if (fail.code != NE_NOERROR)
    {
      Vprintf("Error from f07fdc.\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }

  /* Print factor */
  x04cac(order, matrix, Nag_NonUnitDiag, n, n, a, pda,
         "Factor", 0, &fail);
  if (fail.code != NE_NOERROR)
    {
      Vprintf("Error from x04cac.\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }
 END:
  if (a) NAG_FREE(a);
  return exit_status;
}