What is the formula for the peak envelope created in MatLab?

What is the original formula for the peak envelope created in MatLab?

envelope(a,b,'peak')

I don't know if it uses a Hilbert transform or not.

Answer 1

[Nikhil]

Hey Minoru,

You can get the reference from this page for peak envelope: https://in.mathworks.com/help/signal/ref/envelope.html .

Hope this will help you out.

[Minoru Hoshiyama]

Hi,

I missed the first paragraph on the page you mentioned. It has been resolved.

Thank you very much for your prompt attention.

Minoru

Answer 2

[Jacob Mathew]

Hi Minoru,

This is the link to the documentation of evelope function: https://in.mathworks.com/help/signal/ref/envelope.html

Under the Description Tab, it is mentioned as follows:

[yupper,ylower] = envelope(x)

Here the description mentions that it returns the upper and lower envelopes of the input sequence, x, as the magnitude of its analytic signal. The analytic signal of x is found using the discrete Fourier transform as implemented in hilbert. The function initially removes the mean of x and adds it back after computing the envelopes. If x is a matrix, then envelope operates independently over each column of x.

[Minoru Hoshiyama]

Hi,

I missed the first paragraph on the page you mentioned. It has been resolved.

Thank you very much for your prompt attention.

Minoru