//(1)
double tr, tt, re, im;
ob2.get_r_theta(tr, tt);
re = r * cos(theta) + tr * cos(tt);
im = r * sin(theta) + tr * sin(tt);
temp = complex(sqrt(re * re + im * im), atan2(im, re));
//(2)
double rr, tt, re, im;
ob2.get_r_theta(rr, tt);
re = r * cos(theta) - rr * cos(tt);
im = r * sin(theta) - rr * sin(tt);
temp = complex(sqrt(re * re + im * im), atan2(im, re));
//(3)
double rr, tt;
ob2.get_r_theta(rr, tt);
temp = complex(r * rr, theta + tt);
//(4)
double rr, tt;
ob2.get_r_theta(rr, tt);
temp = complex(r / rr, theta - tt);
//(5)
double rr, tt;
ob2.get_r_theta(rr, tt);
r = rr; theta = tt;