Files
lammps/lib/linalg/z_lmp_div.cpp

32 lines
750 B
C++

#include "lmp_f2c.h"
extern "C" {
void z_lmp_div(doublecomplex *c, doublecomplex *a, doublecomplex *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) {
if (a->i != 0 || a->r != 0) abi = 1.;
c->i = c->r = abi / abr;
return;
}
ratio = 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 = 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;
}
}