/* nag_dpftrf (f07wdc) Example Program.
 *
 * Copyright 2014 Numerical Algorithms Group.
 *
 * Mark 25, 2014.
 */

#include <nag.h>
#include <nag_stdlib.h>
#include <nagf01.h>
#include <nagf07.h>
#include <nagx04.h>

int main(void)
{
  /* Scalars */
  Integer        exit_status = 0;
  Integer        i, j, k, lar1, lar2, lenar, n, pdar, pda, q;
  /*  Arrays*/
  double         *ar = 0, *a = 0;
  char           nag_enum_arg[40];
  /* NAG types */
  Nag_RFP_Store  transr;
  Nag_UploType   uplo;
  Nag_OrderType  order;
  Nag_MatrixType matrix;
  NagError       fail;

#ifdef NAG_COLUMN_MAJOR
  order = Nag_ColMajor;
#define AR(I,J) ar[J*pdar + I]
#else
  order = Nag_RowMajor;
#define AR(I,J) ar[I*pdar + J]
#endif

  INIT_FAIL(fail);

  printf("nag_dpftrf (f07wdc) Example Program Results\n");
  /* Skip heading in data file*/
  scanf("%*[^\n] ");
  scanf("%ld", &n);
  scanf("%39s", nag_enum_arg);
  uplo = (Nag_UploType) nag_enum_name_to_value(nag_enum_arg);
  scanf("%39s%*[^\n]", nag_enum_arg);
  transr = (Nag_RFP_Store) nag_enum_name_to_value(nag_enum_arg);

  lenar = (n * (n + 1))/2;
  pda = n;
  if (!(ar = NAG_ALLOC(lenar, double)) ||
      !(a = NAG_ALLOC(pda*n, double)))
    {
      printf("Allocation failure\n");
      exit_status = -1;
      goto END;
    }

  /* Setup dimensions for RFP array ar. */
  k = n/2;
  q = n - k;
  if (transr==Nag_RFP_Normal) {
    lar1 = 2*k+1;
    lar2 = q;
  } else {
    lar1 = q;
    lar2 = 2*k+1;
  }
  if (order==Nag_RowMajor) {
    pdar = lar2;
  } else {
    pdar = lar1;
  }
  /* Read matrix into RFP array ar. */
  for (i = 0; i < lar1; i++) {
    for (j = 0; j < lar2; j++) {
      scanf("%lf ", &AR(i,j));
    }
  }

  /* Factorize A using nag_dpftrf (f07wdc) which performs a 
   * Cholesky factorization of real symmetric positive definite matrix in
   * Rectangular Full Packed format.
   */
  nag_dpftrf(order, transr, uplo, n, ar, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_dpftrf (f07wdc)\n%s\n", fail.message);
    exit_status = 1;
    goto END;
  }
  printf("\n");

  /* Convert factor to full array form for printing using nag_dtfttr (f01vgc).
   * Copies a real triangular matrix from Rectangular Full Packed format
   * to full matrix format
   */
  nag_dtfttr(order, transr, uplo, n, ar, a, pda, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_dtfttr (f01vgc)\n%s\n", fail.message);
    exit_status = 2;
    goto END;
  }

  matrix = (uplo == Nag_Lower ? Nag_LowerMatrix : Nag_UpperMatrix);
  /* 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, "Factor",
                         0, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_gen_real_mat_print (x04cac)\n%s\n", fail.message);
    exit_status = 3;
  }

 END:
  NAG_FREE(ar);
  NAG_FREE(a);
  return exit_status;
}