Converting cartesian to polar coordinates I am trying to find a way to convert cartesian to polar coordinates.
A quick search gives me:
$$r^2=x^2+y^2$$
$$θ=\arctan(y/x)$$
so far so good, but what happens when $x=0$. I know in that case theta is $\pi/2$ but how can I compute that from a computer point of view? or should I just make a special case?

read $ x$
read $ y$
$r :=\sqrt{x^2+y^2}$
if $ x> 0 $ then $\theta=\arctan(\frac yx)$
if $ x<0 $ then $ \theta=\arctan(\frac yx) +\pi$
if $ x=0 $ and $y>0$ then $\theta=\frac \pi 2$
if $ x=0$ and $y<0$ then $\theta = -\frac \pi 2$
