cart2pol angle sin 0 to 2pi range instead of -pi to pi range?

I have a huge set of x and y coordinates that I have converted to polar coordinates using cart2pol, but I need to have my range of angles to be 0 to 2pi instead of -pi to pi. How can I do this without manually adding 2pi to each negative theta?

Answer 1

[John D'Errico]

The most efficient solution is to use mod. Thus...

theta = mod(cart2pol(x,y),2*pi);

This works, because what you really want is to add 2*pi to the angle, whenever the angle is less than zero. mod does exactly that. And, yes, mod works for non-integer moduli, and of course mod is vectorized, so it does everything you need without even a need for a loop.

Answer 2

[theodore panagos]

You can use the formula:

atan(x,y)=pi()-pi()/2*(1+sign(x))*(1-sign(y^2))-pi()/4*(2+sign(x))*sign(y)

      -sign(x*y)*atan((abs(x)-abs(y))/(abs(x)+abs(y)))

           there is  x=x2-x1  and y=y2-y1

          The formula give the angle from 0 to2pi for all the values x and y

          For x=y=0 the result is undefined.