freebsd-dev/contrib/libf2c/libF77/c_div.c
2003-07-11 03:42:19 +00:00

44 lines
841 B
C

#include "f2c.h"
extern void sig_die (char *, int);
void
c_div (complex * c, complex * a, complex * b)
{
double ratio, den;
double abr, abi, cr;
if ((abr = b->r) < 0.)
abr = -abr;
if ((abi = b->i) < 0.)
abi = -abi;
if (abr <= abi)
{
if (abi == 0)
{
#ifdef IEEE_COMPLEX_DIVIDE
float af, bf;
af = bf = abr;
if (a->i != 0 || a->r != 0)
af = 1.;
c->i = c->r = af / bf;
return;
#else
sig_die ("complex division by zero", 1);
#endif
}
ratio = (double) b->r / b->i;
den = b->i * (1 + ratio * ratio);
cr = (a->r * ratio + a->i) / den;
c->i = (a->i * ratio - a->r) / den;
}
else
{
ratio = (double) b->i / b->r;
den = b->r * (1 + ratio * ratio);
cr = (a->r + a->i * ratio) / den;
c->i = (a->i - a->r * ratio) / den;
}
c->r = cr;
}