How to find the phase difference between two signals

Hi,

I would like to know how can I find the phase difference between:

s1=sin(wt)
s2=sin(wt+theta)

Is there a way to find theta given two graphics? How to find the delay and convert to angle.

If possible, give some codes and a brief explanation of them.

Thanks!

Answer 1

[Honglei Chen]

You can multiply, i.e., mix, the two signal and do a low pass filtering. You will then basically get a signal of cos(theta). I'm not sure if I understand your second question regarding convert the delay to angle, can you fill in more information here?