main.c

#include "punkty.h"
#include "funkcje_trygonometryczne.h"
#include "aproksymator_f_trygonometrycznymi.h"

#include <getopt.h>
#include <stdio.h>
#include <stdlib.h>

char *usage =
  "Usage: %s -s spline-file [-p points-file] [ -g gnuplot-file [-f from_x -t to_x -n n_points ] ]\n"
  "            if points-file is given then\n"
  "               reads discrete 2D points from points-file\n"
  "               writes spline approximation to spline-file\n"
  "               - number of points should be >= 4\n"
  "            else (points-file not given)\n"
  "               reads spline from spline-file\n"
  "            endfi\n"
  "            if gnuplot-file is given then\n"
  "               makes table of n_points within <from_x,to_x> range\n"
  "               - from_x defaults to x-coordinate of the first point in points-file,\n"
  "               - to_x defaults to x-coordinate of the last point\n"
  "               - n_points defaults to 100\n"
  "               - n_points must be > 1\n"
  "            endif\n";

int
main (int argc, char **argv)
{
  int opt;
  char *inp = NULL;
  char *out = NULL;
  char *gpt = NULL;
  double fromX = 0;
  double toX = 0;
  int n = 100;
	char *progname= argv[0];

  punkty_t pts;
  parametry_funkcji_t par;

  pts.n = 0;
  par.n = 0;

  /* process options, save user choices */
  while ((opt = getopt (argc, argv, "p:s:g:f:t:n:")) != -1) {
    switch (opt) {
    case 'p':
      inp = optarg;
      break;
    case 's':
      out = optarg;
      break;
    case 'g':
      gpt = optarg;
      break;
    case 'f':
      fromX = atof (optarg);
      break;
    case 't':
      toX = atof (optarg);
      break;
    case 'n':
      n = atoi (optarg);
      break;
    default:                   /* '?' */
      fprintf (stderr, usage, progname);
      exit (EXIT_FAILURE);
    }
  }
	if( optind < argc ) {
		fprintf( stderr, "\nBad parameters!\n" );
		for( ; optind < argc; optind++ )
			fprintf( stderr, "\t\"%s\"\n", argv[optind] );
		fprintf( stderr, "\n" );
		fprintf( stderr, usage, progname );
		exit( EXIT_FAILURE );
	}

  /* if points-file was given, then read points, generate spline, save it to file */
  if (inp != NULL) {
    FILE *ouf = NULL; /* we shall open it later, when we shall get points */

    FILE *inf = fopen (inp, "r");
    if (inf == NULL) {
      fprintf (stderr, "%s: can not read points file: %s\n\n", argv[0], inp);
      exit (EXIT_FAILURE);
    }

    if (czytaj_bledne_punkty (inf, &pts)) {
      fprintf (stderr, "%s: bad contents of points file: %s\n\n", argv[0],
               inp);
      exit (EXIT_FAILURE);
    }
    else
      fclose (inf);

    ouf = fopen (out, "w");
    if (ouf == NULL) {
      fprintf (stderr, "%s: can not write spline file: %s\n\n", argv[0], out);
      exit (EXIT_FAILURE);
    }

    oblicz_a_b (&pts, &par);

    if( par.n > 0 )
			wypisz_parametry (&par, ouf);

    fclose (ouf);
  } else if (out != NULL) {  /* if point-file was NOT given, try to read splines from a file */
    FILE *parf = fopen (out, "r");
    if (parf == NULL) {
      fprintf (stderr, "%s: can not read spline file: %s\n\n", argv[0], inp);
      exit (EXIT_FAILURE);
    }
    if (czytaj_parametry (&par, parf)) {
      fprintf (stderr, "%s: bad contents of spline file: %s\n\n", argv[0],
               inp);
      exit (EXIT_FAILURE);
    }
  } else { /* ponts were not given nor spline was given -> it is an error */
    fprintf (stderr, usage, argv[0]);
    exit (EXIT_FAILURE);
  }

  if (par.n < 1) { /* check if there is a valid spline */
    fprintf (stderr, "%s: bad spline: n=%d\n\n", argv[0], par.n);
    exit (EXIT_FAILURE);
  }

  /* check if plot was requested and generate it if yes */
  if (gpt != NULL && n > 1) { 
    FILE *gpf = fopen (gpt, "w");
    int i;
    double dx;
		if( fromX == 0 && toX == 0 ) { /* calculate plot range if it was not specified */
			if( pts.n > 1 ) {
				fromX= pts.x[0];
				toX=   pts.x[pts.n-1];
			} else if( par.n > 1 ) {
				fromX= par.x[0];
				toX=   par.x[par.n-1];
			} else {
				fromX= 0;
				toX= 1;
			}
		}
    dx = (toX - fromX) / (n - 1);

    if (gpf == NULL) {
      fprintf (stderr, "%s: can not write gnuplot file: %s\n\n", argv[0],
               gpt);
      exit (EXIT_FAILURE);
    }

    for (i = 0; i < n; i++) {
      fprintf (gpf, "%g %g\n", fromX + i * dx, wartosc_wielomianu (&par, fromX + i * dx));
	}
    fclose (gpf);
  }

  return 0;
}