ref: de1a460fa13ed2bffbdc3cb046cc8831c1d22008
dir: /sys/src/cmd/astro/cosadd.c/
#include "astro.h" void icosadd(double *fp, char *cp) { cafp = fp; cacp = cp; } double cosadd(int n, double coef, ...) { double *coefp; char *cp; int i; double sum, a1, a2; sum = 0; cp = cacp; loop: a1 = *cafp++; if(a1 == 0) { cacp = cp; return sum; } a2 = *cafp++; i = n; coefp = &coef; do a2 += *cp++ * *coefp++; while(--i); sum += a1 * cos(a2); goto loop; } double sinadd(int n, double coef, ...) { double *coefp; char *cp; int i; double sum, a1, a2; sum = 0; cp = cacp; loop: a1 = *cafp++; if(a1 == 0) { cacp = cp; return sum; } a2 = *cafp++; i = n; coefp = &coef; do a2 += *cp++ * *coefp++; while(--i); sum += a1 * sin(a2); goto loop; }