1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
|
#include "f2c.h"
#ifdef KR_headers
extern VOID sig_die();
VOID c_div(c, a, b)
complex *a, *b, *c;
#else
extern void sig_die(char*,int);
void c_div(complex *c, complex *a, complex *b)
#endif
{
double ratio, den;
double abr, abi;
if( (abr = b->r) < 0.)
abr = - abr;
if( (abi = b->i) < 0.)
abi = - abi;
if( abr <= abi )
{
if(abi == 0)
sig_die("complex division by zero", 1);
ratio = (double)b->r / b->i ;
den = b->i * (1 + ratio*ratio);
c->r = (real) ((a->r*ratio + a->i) / den);
c->i = (real) ((a->i*ratio - a->r) / den);
}
else
{
ratio = (double)b->i / b->r ;
den = b->r * (1 + ratio*ratio);
c->r = (real) ((a->r + a->i*ratio) / den);
c->i = (real) ((a->i - a->r*ratio) / den);
}
}
|