/* nag_zpbrfs (f07hvc) Example Program.
 *
 * Copyright 2017 Numerical Algorithms Group.
 *
 * Mark 26.1, 2017.
 */

#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, pdafb, pdb, pdx;
  Integer ferr_len, berr_len;
  Integer exit_status = 0;
  Nag_UploType uplo;
  NagError fail;
  Nag_OrderType order;

  /* Arrays */
  char nag_enum_arg[40];
  Complex *ab = 0, *afb = 0, *b = 0, *x = 0;
  double *berr = 0, *ferr = 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 AFB_UPPER(I, J) afb[(J-1)*pdafb + k + I - J - 1]
#define AFB_LOWER(I, J) afb[(J-1)*pdafb + I - J]
#define B(I, J)         b[(J-1)*pdb + I - 1]
#define X(I, J)         x[(J-1)*pdx + 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 AFB_UPPER(I, J) afb[(I-1)*pdafb + J - I]
#define AFB_LOWER(I, J) afb[(I-1)*pdafb + k + J - I - 1]
#define B(I, J)         b[(I-1)*pdb + J - 1]
#define X(I, J)         x[(I-1)*pdx + J - 1]
  order = Nag_RowMajor;
#endif

  INIT_FAIL(fail);

  printf("nag_zpbrfs (f07hvc) Example Program Results\n\n");

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

  ferr_len = nrhs;
  berr_len = nrhs;

  /* Allocate memory */
  if (!(berr = NAG_ALLOC(berr_len, double)) ||
      !(ferr = NAG_ALLOC(ferr_len, double)) ||
      !(ab = NAG_ALLOC((kd + 1) * n, Complex)) ||
      !(afb = NAG_ALLOC((kd + 1) * n, Complex)) ||
      !(b = NAG_ALLOC(n * nrhs, Complex)) ||
      !(x = NAG_ALLOC(n * nrhs, Complex)))
  {
    printf("Allocation failure\n");
    exit_status = -1;
    goto END;
  }

  /* Read A from data file */
  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);

  k = kd + 1;
  if (uplo == Nag_Upper) {
    for (i = 1; i <= n; ++i) {
      for (j = i; j <= MIN(i + kd, n); ++j) {
        scanf(" ( %lf , %lf )", &AB_UPPER(i, j).re, &AB_UPPER(i, j).im);
      }
    }
    scanf("%*[^\n] ");
  }
  else {
    for (i = 1; i <= n; ++i) {
      for (j = MAX(1, i - kd); j <= i; ++j) {
        scanf(" ( %lf , %lf )", &AB_LOWER(i, j).re, &AB_LOWER(i, j).im);
      }
    }
    scanf("%*[^\n] ");
  }
  /* Read B from data file */
  for (i = 1; i <= n; ++i) {
    for (j = 1; j <= nrhs; ++j)
      scanf(" ( %lf , %lf )", &B(i, j).re, &B(i, j).im);
  }
  scanf("%*[^\n] ");
  /* Copy A to AF and B to X */
  if (uplo == Nag_Upper) {
    for (i = 1; i <= n; ++i) {
      for (j = i; j <= MIN(i + kd, n); ++j) {
        AFB_UPPER(i, j).re = AB_UPPER(i, j).re;
        AFB_UPPER(i, j).im = AB_UPPER(i, j).im;
      }
    }
  }
  else {
    for (i = 1; i <= n; ++i) {
      for (j = MAX(1, i - kd); j <= i; ++j) {
        AFB_LOWER(i, j).re = AB_LOWER(i, j).re;
        AFB_LOWER(i, j).im = AB_LOWER(i, j).im;
      }
    }
  }
  for (i = 1; i <= n; ++i) {
    for (j = 1; j <= nrhs; ++j) {
      X(i, j).re = B(i, j).re;
      X(i, j).im = B(i, j).im;
    }
  }
  /* Factorize A in the array AFP */
  /* nag_zpbtrf (f07hrc).
   * Cholesky factorization of complex Hermitian
   * positive-definite band matrix
   */
  nag_zpbtrf(order, uplo, n, kd, afb, pdafb, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_zpbtrf (f07hrc).\n%s\n", fail.message);
    exit_status = 1;
    goto END;
  }
  /* Compute solution in the array X */
  /* 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, n, kd, nrhs, afb, pdafb, x, pdx, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_zpbtrs (f07hsc).\n%s\n", fail.message);
    exit_status = 1;
    goto END;
  }
  /* Improve solution, and compute backward errors and */
  /* estimated bounds on the forward errors */
  /* nag_zpbrfs (f07hvc).
   * Refined solution with error bounds of complex Hermitian
   * positive-definite band system of linear equations,
   * multiple right-hand sides
   */
  nag_zpbrfs(order, uplo, n, kd, nrhs, ab, pdab, afb, pdafb,
             b, pdb, x, pdx, ferr, berr, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_zpbrfs (f07hvc).\n%s\n", fail.message);
    exit_status = 1;
    goto END;
  }
  /* Print details of solution */

  /* nag_gen_complx_mat_print_comp (x04dbc).
   * Print complex general matrix (comprehensive)
   */
  fflush(stdout);
  nag_gen_complx_mat_print_comp(order, Nag_GeneralMatrix, Nag_NonUnitDiag, n,
                                nrhs, x, pdx, Nag_BracketForm, "%7.4f",
                                "Solution(s)", Nag_IntegerLabels,
                                0, Nag_IntegerLabels, 0, 80, 0, 0, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_gen_complx_mat_print_comp (x04dbc).\n%s\n",
           fail.message);
    exit_status = 1;
    goto END;
  }
  printf("\nBackward errors (machine-dependent)\n");
  for (j = 1; j <= nrhs; ++j)
    printf("%11.1e%s", berr[j - 1], j % 7 == 0 ? "\n" : " ");
  printf("\nEstimated forward error bounds (machine-dependent)\n");
  for (j = 1; j <= nrhs; ++j)
    printf("%11.1e%s", ferr[j - 1], j % 7 == 0 ? "\n" : " ");
  printf("\n");
END:
  NAG_FREE(berr);
  NAG_FREE(ferr);
  NAG_FREE(ab);
  NAG_FREE(afb);
  NAG_FREE(b);
  NAG_FREE(x);
  return exit_status;
}