I am taking the Hilbert transform of a signal in Matlab and I don't understand part of the result.
Below are the complete signal $z(t)$ and phase $\phi(t)$, obtained with
phi=unwrap(angle(hilbert(z)))
I noticed a jump around point 400, so I zoomed this region. This is shown below.
Although the signal in this region is very well behaved, the phase has an almost discontinuity. Why?
It is not due to the unwrap command, as we can see below
The data can be found here