/* nag_dsyr2 (f16prc) Example Program.
 *
 * Copyright 2014 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        exit_status, i, incx, incy, j, n, pda, xlen, ylen;

  /* Arrays */
  double         *a = 0, *x = 0, *y = 0;
  char           nag_enum_arg[40];

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

#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

  exit_status = 0;
  INIT_FAIL(fail);

  printf("nag_dsyr2 (f16prc) Example Program Results\n\n");

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

  /* Read the problem dimension */
  scanf("%ld%*[^\n] ", &n);

  /* Read the uplo storage parameter */
  scanf("%39s%*[^\n] ", nag_enum_arg);
  /* nag_enum_name_to_value (x04nac).
   * Converts NAG enum member name to value
   */
  uplo = (Nag_UploType) nag_enum_name_to_value(nag_enum_arg);

  /* Read scalar parameters */
  scanf("%lf%lf%*[^\n] ", &alpha, &beta);
  /* Read increment parameters */
  scanf("%ld%ld%*[^\n] ", &incx, &incy);

  pda = n;

  xlen = MAX(1, 1 + (n - 1)*ABS(incx));
  ylen = MAX(1, 1 + (n - 1)*ABS(incy));

  if (n > 0)
    {
      /* Allocate memory */
      if (!(a = NAG_ALLOC(pda*n, double)) ||
          !(x = NAG_ALLOC(xlen, double)) ||
          !(y = NAG_ALLOC(ylen, double)))
        {
          printf("Allocation failure\n");
          exit_status = -1;
          goto END;
        }
    }
  else
    {
      printf("Invalid n\n");
      exit_status = 1;
      goto END;
    }

  /* Input matrix A and vector x */

  if (uplo == Nag_Upper)
    {
      for (i = 1; i <= n; ++i)
        {
          for (j = i; j <= n; ++j)
            scanf("%lf", &A(i, j));
          scanf("%*[^\n] ");
        }
    }
  else
    {
      for (i = 1; i <= n; ++i)
        {
          for (j = 1; j <= i; ++j)
            scanf("%lf", &A(i, j));
          scanf("%*[^\n] ");
        }
    }
  for (i = 0; i < xlen; ++i)
    scanf("%lf%*[^\n] ", &x[i]);
  for (i = 0; i < ylen; ++i)
    scanf("%lf%*[^\n] ", &y[i]);

  /* nag_dsyr2 (f16prc).
   * Rank two update of real symmetric matrix.
   *
   */
  nag_dsyr2(order, uplo, n, alpha, x, incx, y, incy, beta, a, pda,
            &fail);
  if (fail.code != NE_NOERROR)
    {
      printf("Error from nag_dsyr2 (f16prc).\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }

  if (uplo == Nag_Upper)
    {
      matrix = Nag_UpperMatrix;
    }
  else
    {
      matrix = Nag_LowerMatrix;
    }
  /* Print updated matrix A */
  /* nag_gen_real_mat_print (x04cac).
   * Print real general matrix (easy-to-use)
   */
  fflush(stdout);
  nag_gen_real_mat_print(order, matrix, Nag_NonUnitDiag, n,
                         n, a, pda, "Updated Matrix A", 0, &fail);
  if (fail.code != NE_NOERROR)
    {
      printf("Error from nag_gen_real_mat_print (x04cac).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }

 END:
  NAG_FREE(a);
  NAG_FREE(x);
  NAG_FREE(y);

  return exit_status;
}