cantera/ext/f2c_libs/c_div.c
2012-02-03 23:41:00 +00:00

53 lines
955 B
C

#include "f2c.h"
#ifdef __cplusplus
extern "C" {
#endif
#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, 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 = (real) ((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 = (real) ((a->i - a->r*ratio) / den);
}
c->r = (real) cr;
}
#ifdef __cplusplus
}
#endif