/* nag_zpbtrs (f07hsc) 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, k, kd, n, nrhs, pdab, pdb;
  Integer  exit_status=0;
  Nag_UploType uplo_enum;
  NagError fail;
  Nag_OrderType order;

  /* Arrays */
  char    uplo[2];
  Complex  *ab=0, *b=0;

#ifdef NAG_COLUMN_MAJOR
#define AB_UPPER(I,J) ab[(J-1)*pdab + k + I - J - 1]
#define AB_LOWER(I,J) ab[(J-1)*pdab + I - J]
#define B(I,J) b[(J-1)*pdb + I - 1]
  order = Nag_ColMajor;
#else
#define AB_UPPER(I,J) ab[(I-1)*pdab + J - I]
#define AB_LOWER(I,J) ab[(I-1)*pdab + k + J - I - 1]
#define B(I,J) b[(I-1)*pdb + J - 1]
  order = Nag_RowMajor;
#endif

  INIT_FAIL(fail);
  Vprintf("nag_zpbtrs (f07hsc) Example Program Results\n\n");

  /* Skip heading in data file */
  Vscanf("%*[^\n] ");
  Vscanf("%ld%ld%ld%*[^\n] ", &n, &kd, &nrhs);
  pdab = kd + 1;
#ifdef NAG_COLUMN_MAJOR
  pdb = n;
#else
  pdb = nrhs;
#endif

  /* Allocate memory */
  if ( !(ab = NAG_ALLOC((kd+1) * n, Complex)) ||
       !(b = NAG_ALLOC(n * nrhs, Complex)) )
    {
      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;
  else if (*(unsigned char *)uplo == 'U')
    uplo_enum = Nag_Upper;
  else
    {
      Vprintf("Unrecognised character for Nag_UploType type\n");
      exit_status = -1;
      goto END;
    }
  k = kd + 1;
  if (uplo_enum == Nag_Upper)
    {
      for (i = 1; i <= n; ++i)
        {
          for (j = i; j <= MIN(i+kd,n); ++j)
            Vscanf(" ( %lf , %lf )", &AB_UPPER(i,j).re, &AB_UPPER(i,j).im);
        }
      Vscanf("%*[^\n] ");
    }
  else
    {
      for (i = 1; i <= n; ++i)
        {
          for (j = MAX(1,i-kd); j <= i; ++j)
            Vscanf(" ( %lf , %lf )", &AB_LOWER(i,j).re, &AB_LOWER(i,j).im);
        }
      Vscanf("%*[^\n] ");
    }
  /* Read B from data file */
  for (i = 1; i <= n; ++i)
    {
      for (j = 1; j <= nrhs; ++j)
        Vscanf(" ( %lf , %lf )", &B(i,j).re, &B(i,j).im);
    }
  Vscanf("%*[^\n] ");

  /* Factorize A */
  /* nag_zpbtrf (f07hrc).
   * Cholesky factorization of complex Hermitian
   * positive-definite band matrix
   */
  nag_zpbtrf(order, uplo_enum, n, kd, ab, pdab, &fail);
  if (fail.code != NE_NOERROR)
    {
      Vprintf("Error from nag_zpbtrf (f07hrc).\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }

  /* Compute solution */
  /* nag_zpbtrs (f07hsc).
   * Solution of complex Hermitian positive-definite band
   * system of linear equations, multiple right-hand sides,
   * matrix already factorized by nag_zpbtrf (f07hrc)
   */
  nag_zpbtrs(order, uplo_enum, n, kd, nrhs, ab, pdab, b, pdb, &fail);
  if (fail.code != NE_NOERROR)
    {
      Vprintf("Error from nag_zpbtrs (f07hsc).\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }
  /* Print solution */
  /* nag_gen_complx_mat_print_comp (x04dbc).
   * Print complex general matrix (comprehensive)
   */
  nag_gen_complx_mat_print_comp(order, Nag_GeneralMatrix, Nag_NonUnitDiag, n,
                                nrhs, b, pdb, Nag_BracketForm, "%7.4f",
                                "Solution(s)", Nag_IntegerLabels,  0,
                                Nag_IntegerLabels,  0, 80, 0, 0, &fail);
  if (fail.code != NE_NOERROR)
    {
      Vprintf("Error from nag_gen_complx_mat_print_comp (x04dbc).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }
 END:
  if (ab) NAG_FREE(ab);
  if (b) NAG_FREE(b);
  return exit_status;
}