/* nag_dsyr2k (f16yrc) Example Program.
 *
 * Copyright 2005 Numerical Algorithms Group.
 *
 * Mark 8, 2005.
 */

#include <stdio.h>
#include <nag.h>
#include <nag_stdlib.h>
#include <nagf16.h>
#include <nagx04.h>

int main(void)
{

  /* Scalars */
  double alpha, beta;
  Integer adim1, adim2, exit_status, i, j, k, n, pda, pdb, pdc;

  /* Arrays */
  double *a=0, *b=0, *c=0;
  char nag_enum_arg[40];

  /* Nag Types */
  NagError fail;
  Nag_OrderType order;
  Nag_UploType uplo;
  Nag_TransType trans;
  Nag_MatrixType matrix;

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

  exit_status = 0;
  INIT_FAIL(fail);

  Vprintf( "nag_dsyr2k (f16yrc) Example Program Results\n\n");

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

  /* Read the problem dimensions */
  Vscanf("%ld%ld%*[^\n] ", &n, &k);

  /* Read the uplo parameter */
  Vscanf("%s%*[^\n] ", nag_enum_arg);
  /* nag_enum_name_to_value(x04nac).
   * Converts NAG enum member name to value
   */
  uplo = nag_enum_name_to_value(nag_enum_arg);
  /* Read the transpose parameter */
  Vscanf("%s%*[^\n] ", nag_enum_arg);
  /* nag_enum_name_to_value(x04nac), see above. */
  trans = nag_enum_name_to_value(nag_enum_arg);
  /* Read scalar parameters */
  Vscanf("%lf%lf%*[^\n] ", &alpha, &beta);

  if (trans == Nag_NoTrans) {
    adim1 = n;
    adim2 = k;
  } else {
    adim1 = k;
    adim2 = n;
  }

#ifdef NAG_COLUMN_MAJOR
  pda = adim1;
#else
  pda = adim2;
#endif
  pdb = pda;
  pdc = n;
  if (k > 0 && n > 0)
    {
      /* Allocate memory */
      if ( !(a = NAG_ALLOC(k*n, double)) ||
           !(b = NAG_ALLOC(k*n, double)) ||
           !(c = NAG_ALLOC(n*n, double)) )
        {
          Vprintf("Allocation failure\n");
          exit_status = -1;
          goto END;
        }
    }
  else
    {
      Vprintf("Invalid k or n\n");
      exit_status = 1;
      return exit_status;
    }

  /* Input matrix A. */
  for (i = 1; i <= adim1; ++i)
    {
      for (j = 1; j <= adim2; ++j)
        Vscanf("%lf", &A(i,j));
      Vscanf("%*[^\n] ");
    }
  /* Input matrix B. */
  for (i = 1; i <= adim1; ++i)
    {
      for (j = 1; j <= adim2; ++j)
        Vscanf("%lf", &B(i,j));
      Vscanf("%*[^\n] ");
    }
  /* Input matrix C. */
  if (uplo == Nag_Upper)
    {
      for (i = 1; i <= n; ++i)
        {
          for (j = i; j <= n; ++j)
            Vscanf("%lf", &C(i,j));
        }
      Vscanf("%*[^\n] ");
    }
  else
    {
      for (i = 1; i <= n; ++i)
        {
          for (j = 1; j <= i; ++j)
            Vscanf("%lf", &C(i,j));
        }
      Vscanf("%*[^\n] ");
    }

  /* nag_dsyr2k(f16yrc).
   * Rank 2k update of symmetric matrix.
   *
   */
  nag_dsyr2k(order, uplo, trans, n, k, alpha, a, pda, b, pdb, beta,
             c, pdc, &fail);
  if (fail.code != NE_NOERROR)
    {
      Vprintf("Error from nag_dsyr2k.\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }
  if (uplo == Nag_Upper)
    {
      matrix = Nag_UpperMatrix;
    }
  else
    {
       matrix = Nag_LowerMatrix;
    }
  /* Print updated matrix C */
  /* nag_gen_real_mat_print (x04cac).
   * Print real general matrix (easy-to-use)
   */
  nag_gen_real_mat_print(order, matrix, Nag_NonUnitDiag, n,
                         n, c, pdc, "Updated Matrix C", 0, &fail);
  if (fail.code != NE_NOERROR)
    {
      Vprintf("Error from nag_gen_real_mat_print (x04cac).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }
 END:
  if (a) NAG_FREE(a);
  if (b) NAG_FREE(b);
  if (c) NAG_FREE(c);

  return exit_status;
}