This is moonnf.c in view mode; [Download] [Up]
#include <stdio.h>
#include <math.h>
#include "astro.h"
#define unw(w,z) ((w)-floor((w)/(z))*(z))
/* given a modified Julian date, mjd, return the mjd of the new
* and full moons about then, mjdn and mjdf.
* TODO: exactly which ones does it find? eg:
* 5/28/1988 yields 5/15 and 5/31
* 5/29 6/14 6/29
*/
moonnf (mjd, mjdn, mjdf)
double mjd;
double *mjdn, *mjdf;
{
int mo, yr;
double dy;
double mjd0;
double k, tn, tf, t;
mjd_cal (mjd, &mo, &dy, &yr);
cal_mjd (1, 0., yr, &mjd0);
k = (yr-1900+((mjd-mjd0)/365))*12.3685;
k = floor(k+0.5);
tn = k/1236.85;
tf = (k+0.5)/1236.85;
t = tn;
m (t, k, mjdn);
t = tf;
k += 0.5;
m (t, k, mjdf);
}
static
m (t, k, mjd)
double t, k;
double *mjd;
{
double t2, a, a1, b, b1, c, ms, mm, f, ddjd;
t2 = t*t;
a = 29.53*k;
c = degrad(166.56+(132.87-9.173e-3*t)*t);
b = 5.8868e-4*k+(1.178e-4-1.55e-7*t)*t2+3.3e-4*sin(c)+7.5933E-1;
ms = 359.2242+360*unw(k/1.236886e1,1)-(3.33e-5+3.47e-6*t)*t2;
mm = 306.0253+360*unw(k/9.330851e-1,1)+(1.07306e-2+1.236e-5*t)*t2;
f = 21.2964+360*unw(k/9.214926e-1,1)-(1.6528e-3+2.39e-6*t)*t2;
ms = unw(ms,360);
mm = unw(mm,360);
f = unw(f,360);
ms = degrad(ms);
mm = degrad(mm);
f = degrad(f);
ddjd = (1.734e-1-3.93e-4*t)*sin(ms)+2.1e-3*sin(2*ms)
-4.068e-1*sin(mm)+1.61e-2*sin(2*mm)-4e-4*sin(3*mm)
+1.04e-2*sin(2*f)-5.1e-3*sin(ms+mm)-7.4e-3*sin(ms-mm)
+4e-4*sin(2*f+ms)-4e-4*sin(2*f-ms)-6e-4*sin(2*f+mm)
+1e-3*sin(2*f-mm)+5e-4*sin(ms+2*mm);
a1 = (long)a;
b = b+ddjd+(a-a1);
b1 = (long)b;
a = a1+b1;
b = b-b1;
*mjd = a + b;
}
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.