/* nag_1d_quad_wt_trig (d01anc) Example Program.
 *
 * Copyright 1991 Numerical Algorithms Group.
 *
 * Mark 2, 1991.
 * Mark 6 revised, 2000.
 * Mark 7 revised, 2001.
 */

#include <nag.h>
#include <nagx04.h>
#include <stdio.h>
#include <nag_stdlib.h>
#include <math.h>
#include <nagd01.h>
#include <nagx01.h>

#ifdef __cplusplus
extern "C" {
#endif
static double NAG_CALL g(double x);
#ifdef __cplusplus
}
#endif

int main(int argc, char *argv[])
{
  FILE              *fpout;
  Integer           exit_status = 0;
  double            a, b;
  double            omega;
  double            epsabs, abserr, epsrel, result;
  Nag_TrigTransform wt_func;
  Nag_QuadProgress  qp;
  Integer           max_num_subint;
  NagError          fail;

  INIT_FAIL(fail);

  /* Check for command-line IO options */
  fpout = nag_example_file_io(argc, argv, "-results", NULL);
  fprintf(fpout, "nag_1d_quad_wt_trig (d01anc) Example Program Results\n");
  epsrel = 0.0001;
  epsabs = 0.0;
  a = 0.0;
  b = 1.0;
  /* nag_pi (x01aac).
   * pi
   */
  omega = X01AAC * 10.0;
  wt_func = Nag_Sine;
  max_num_subint = 200;
  /* nag_1d_quad_wt_trig (d01anc).
   * One-dimensional adaptive quadrature, finite interval,
   * sine or cosine weight functions
   */
  nag_1d_quad_wt_trig(g, a, b, omega, wt_func, epsabs, epsrel, max_num_subint,
                      &result, &abserr, &qp, &fail);
  fprintf(fpout, "a      - lower limit of integration  = %9.4f\n", a);
  fprintf(fpout, "b      - upper limit of integration  = %9.4f\n", b);
  fprintf(fpout, "epsabs - absolute accuracy requested = %11.2e\n", epsabs);
  fprintf(fpout, "epsrel - relative accuracy requested = %11.2e\n\n", epsrel);
  if (fail.code != NE_NOERROR)
    fprintf(fpout, "Error from nag_1d_quad_wt_trig (d01anc) %s\n",
            fail.message);
  if (fail.code != NE_INT_ARG_LT && fail.code != NE_BAD_PARAM &&
      fail.code != NE_ALLOC_FAIL && fail.code != NE_NO_LICENCE)
    {
      fprintf(fpout, "result - approximation to the integral  = %10.5f\n",
              result);
      fprintf(fpout, "abserr - estimate of the absolute error = %11.2e\n",
              abserr);
      fprintf(fpout, "qp.fun_count  - number of function evaluations = %4ld\n",
              qp.fun_count);
      fprintf(fpout, "qp.num_subint - number of subintervals used    = %4ld\n",
              qp.num_subint);
      /* Free memory used by qp */
      NAG_FREE(qp.sub_int_beg_pts);
      NAG_FREE(qp.sub_int_end_pts);
      NAG_FREE(qp.sub_int_result);
      NAG_FREE(qp.sub_int_error);
    }
  else
    {
      exit_status = 1;
      goto END;
    }

 END:
  if (fpout != stdout) fclose(fpout);
  return exit_status;
}

static double NAG_CALL g(double x)
{
  return (x > 0.0)?log(x):0.0;
}