How to find signal frequency using find function

Hi,

I was wondering how is it possible to find the signal frequency using the find function.

Thanks in advance.

Answer 1

[Star Strider]

It is possible, although not straightforward, since you need to use find to determine the period, that you can then convert to frequency. See: Curve fitting to a sinusoidal function (link) for one approach.

[Pedro Oliveira]

From the example you gave, I can't quite understand how the find function is used. In my case, I have a sinusoidal signal for which I know the sampling time, but don't know the signal frequency, which I'm suppose to find through the find function.

[Star Strider]

My intent was to refer you to a line in my code that is similar to this anonymous function:

zci = @(v) find(v(:).*circshift(v(:), [-1 0]) <= 0);                    % Returns Approximate Zero-Crossing Indices Of Argument Vector

that you can then use to define the approximate period, and from that, the frequency.

I will leave you to explore that.