Opposite of numpy.unwrap

Question

In Python numpy, there is an unwrap function that:

Unwrap radian phase p by changing absolute jumps greater than discont to their 2*pi complement along

Answer 1

This answer is a slight variation to sega_sai answer which is:

phases = ( phases + np.pi) % (2 * np.pi ) - np.pi

This maps phases to [-pi, pi) -> which means pi is mapped to -pi

Shown here:

In [27]: phases = np.pi

In [28]: phases = ( phases + np.pi) % (2 * np.pi ) - np.pi

In [29]: print phases
-3.14159265359

Which is perfectly legitimate but if you want a mapping of (-pi, pi] then

Times the input and output of the operation buy -1. Like so:

phases =  (( -phases + np.pi) % (2.0 * np.pi ) - np.pi) * -1.0