4 double sqrt(), f__cabs();
5 VOID z_sqrt(r, z) doublecomplex *r, *z;
9 extern double f__cabs(double, double);
10 void z_sqrt(doublecomplex *r, doublecomplex *z)
13 double mag, zi = z->i, zr = z->r;
15 if( (mag = f__cabs(zr, zi)) == 0.)
19 r->r = sqrt(0.5 * (mag + zr) );
24 r->i = sqrt(0.5 * (mag - zr) );