Trying to convert cartesian coordinates to polar coordinates

So when I use cart2pol(x,y) I am getting some random values on my plots that do not line up and are incorrect. I dont have a real good way of describing it but I know its wrong and has to do with my origins cooridnate frame and how I defined it but you can see with pictures what I am talking about.

The first photo is where my data is coming from, a double pendulum with the origin being the center where the pendulum rotates. It has full range of motion 360°. The point masses can and will pass over the x axis (this is where the negatives get to be a problem) If I plot this data take straight from my program(figure1) and use [theta,rho] = cart2pol(x,y) to convert my coordinates to polar my plot looks like this (figure 2). I am concerned about the random dips with the small valleys like mass B at about 1 second and mass A at 4 seconds. Are those dips normal, are the plots correct? Are my cooridnates that are being translated wrong? I dont know but I sure hope you do so please help....

Answer 1

[Star Strider]

‘I am concerned about the random dips with the small valleys like mass B at about 1 second and mass A at 4 seconds. Are those dips normal, are the plots correct?’

The plots appear to be correct.

See if using the unwrap function will eliminate the apparent discontinuities.

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