struct complex { float real, imag; }; c_div(c, a, b) struct complex *a, *b, *c; { double ratio, den; double abr, abi; if( (abr = b->real) < 0.) abr = - abr; if( (abi = b->imag) < 0.) abi = - abi; if( abr <= abi ) { if(abi == 0) abort(); /* fatal("complex division by zero"); */ ratio = b->real / b->imag ; den = b->imag * (1 + ratio*ratio); c->real = (a->real*ratio + a->imag) / den; c->imag = (a->imag*ratio - a->real) / den; } else { ratio = b->imag / b->real ; den = b->real * (1 + ratio*ratio); c->real = (a->real + a->imag*ratio) / den; c->imag = (a->imag - a->real*ratio) / den; } }