add numerical recipes library

lib/nr/k_and_r/recipes/flmoon.c

@@ -0,0 +1,30 @@
+
+#include <math.h>
+#define RAD (3.14159265/180.0)
+
+void flmoon(n,nph,jd,frac)
+float *frac;
+int n,nph;
+long *jd;
+{
+	void nrerror();
+	int i;
+	float am,as,c,t,t2,xtra;
+
+	c=n+nph/4.0;
+	t=c/1236.85;
+	t2=t*t;
+	as=359.2242+29.105356*c;
+	am=306.0253+385.816918*c+0.010730*t2;
+	*jd=2415020+28L*n+7L*nph;
+	xtra=0.75933+1.53058868*c+((1.178e-4)-(1.55e-7)*t)*t2;
+	if (nph == 0 || nph == 2)
+		xtra += (0.1734-3.93e-4*t)*sin(RAD*as)-0.4068*sin(RAD*am);
+	else if (nph == 1 || nph == 3)
+		xtra += (0.1721-4.0e-4*t)*sin(RAD*as)-0.6280*sin(RAD*am);
+	else nrerror("nph is unknown in flmoon");
+	i=(int)(xtra >= 0.0 ? floor(xtra) : ceil(xtra-1.0));
+	*jd += i;
+	*frac=xtra-i;
+}
+#undef RAD