sys/src/cmd/astro/cosadd.c

   1 #include "astro.h"
   2
   3
   4 void
   5 icosadd(double *fp, char *cp)
   6 {
   7
   8         cafp = fp;
   9         cacp = cp;
  10 }
  11
  12 double
  13 cosadd(int n, double coef, ...)
  14 {
  15         double *coefp;
  16         char *cp;
  17         int i;
  18         double sum, a1, a2;
  19
  20         sum = 0;
  21         cp = cacp;
  22
  23 loop:
  24         a1 = *cafp++;
  25         if(a1 == 0) {
  26                 cacp = cp;
  27                 return sum;
  28         }
  29         a2 = *cafp++;
  30         i = n;
  31         coefp = &coef;
  32         do
  33                 a2 += *cp++ * *coefp++;
  34         while(--i);
  35         sum += a1 * cos(a2);
  36         goto loop;
  37 }
  38
  39 double
  40 sinadd(int n, double coef, ...)
  41 {
  42         double *coefp;
  43         char *cp;
  44         int i;
  45         double sum, a1, a2;
  46
  47         sum = 0;
  48         cp = cacp;
  49
  50 loop:
  51         a1 = *cafp++;
  52         if(a1 == 0) {
  53                 cacp = cp;
  54                 return sum;
  55         }
  56         a2 = *cafp++;
  57         i = n;
  58         coefp = &coef;
  59         do
  60                 a2 += *cp++ * *coefp++;
  61         while(--i);
  62         sum += a1 * sin(a2);
  63         goto loop;
  64 }