/* nag_blast_dsyr2 (f16prc) Example Program.
 *
 * Copyright 2021 Numerical Algorithms Group.
 *
 * Mark 27.2, 2021.
 */

#include <nag.h>
#include <stdio.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_blast_dsyr2 (f16prc) Example Program Results\n\n");

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

  /* Read the problem dimension */
  scanf("%" NAG_IFMT "%*[^\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("%" NAG_IFMT "%" NAG_IFMT "%*[^\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_blast_dsyr2 (f16prc).
   * Rank two update of real symmetric matrix.
   *
   */
  nag_blast_dsyr2(order, uplo, n, alpha, x, incx, y, incy, beta, a, pda, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_blast_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_file_print_matrix_real_gen (x04cac).
   * Print real general matrix (easy-to-use)
   */
  fflush(stdout);
  nag_file_print_matrix_real_gen(order, matrix, Nag_NonUnitDiag, n, n, a, pda,
                                 "Updated Matrix A", 0, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_file_print_matrix_real_gen (x04cac).\n%s\n",
           fail.message);
    exit_status = 1;
    goto END;
  }

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

  return exit_status;
}