/* nag_legendre_p (s22aac) Example Program.
 *
 * Copyright 2000 Numerical Algorithms Group.
 *
 * NAG C Library
 *
 * Mark 6, 2000.
 * Mark 7, revised, 2001.
 * Mark 8 revised, 2004.
 *
 */

#include <stdio.h>
#include <string.h>
#include <nag.h>
#include <nagx04.h>
#include <nag_stdlib.h>
#include <nags.h>

int main(int argc, char *argv[])
{
  FILE     *fpin, *fpout;
  Integer  exit_status = 0, m, mode, n, nl;
  NagError fail;
  char     *str = 0;
  double   *p = 0, x;

  INIT_FAIL(fail);

  /* Check for command-line IO options */
  fpin = nag_example_file_io(argc, argv, "-data", NULL);
  fpout = nag_example_file_io(argc, argv, "-results", NULL);

  /* Skip heading in data file */
  fscanf(fpin, "%*[^\n] ");
  fprintf(fpout, "nag_legendre_p (s22aac) Example Program Results\n");
  fscanf(fpin, "%ld %lf %ld %ld", &mode, &x, &m, &nl);
  if (!(p = NAG_ALLOC(nl+1, double)) ||
      !(str = NAG_ALLOC(80, char)))
    {
      fprintf(fpout, "Allocation failure\n");
      exit_status = -1;
      goto END;
    }
  if (mode == 1)
    {
      if (m == 0)
        Vstrcpy(str, "Unnormalized Legendre function values\n");
      else
        Vstrcpy(str, "Unnormalized associated Legendre function values\n");
    }
  else if (mode == 2)
    {
      if (m == 0)
        Vstrcpy(str, "Normalized Legendre function values\n");
      else
        Vstrcpy(str, "Normalized associated Legendre function values\n");
    }

  /* nag_legendre_p (s22aac).
   * Legendre and associated Legendre functions of the first
   * kind with real arguments
   */
  nag_legendre_p(mode, x, m, nl, p, &fail);
  fprintf(fpout, "mode      x      m    nl\n");
  fprintf(fpout, "%3ld    %5.1f%6ld%6ld\n\n", mode, x, m, nl);

  if (fail.code == NE_NOERROR)
    {
      fprintf(fpout, str);
      fprintf(fpout, "\n");
      fprintf(fpout, " n      P(n)\n");
      for (n = 0; n <= nl; ++n)
        fprintf(fpout, "%2ld %13.4e\n", n, p[n]);
    }
  else
    {
      fprintf(fpout, "Error from nag_legendre_p (s22aac).\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }
 END:
  if (fpin != stdin) fclose(fpin);
  if (fpout != stdout) fclose(fpout);
  if (p) NAG_FREE(p);
  if (str) NAG_FREE(str);
  return exit_status;
}