source: buchla-68k/orig/GEMDOS/SINTEST.C

/*
   =============================================================================
        sintest.c -- test the sin() function and floating point stuff
        Version 1 -- 1987-08-10 -- D.N. Lynx Crowe
        Setup for MetaComCo/Lattice C on the Atari 1040ST
   =============================================================================
*/

#include "stdio.h"
#include "limits.h"
#include "math.h"

#define NPTS    360
#define PI2     (2.0 * PI)
#define XI      (PI2 / (float)NPTS)

double  points[NPTS];   /* array of y=sin(x) values */
double  xvals[NPTS];    /* array of x values */

main()
{
        double  x;              /* temporary value */

        int i;                  /* temporary value */

        /* create an array of NPTS points of sin(x) from x=0 to 2 PI radians */

        for (i = 0; i < NPTS; i++) {

                x = (double)i * XI;
                xvals[i] = x;
                points[i] = sin(x);
        }

        for (i = 0; i < NPTS; i++)
                printf("%3d: sin(%2.6f) = %2.6f\n", i, xvals[i], points[i]);

        printf("XI = %3.6f, PI2 = %3.6f, PI = %3.6f\n", XI, PI2, PI);

        exit(0);
}