# Unable to interpret hypothesis testing whetehr a signal is periodic or not

The meaning of P value is probability which should be number between 0 (the event never occurs) and 1 (the event occurs always). significance testing for periodicity using Matlab gives a documentation on how to apply Fisher's statistics to a time series signal for periodicity testing. Some concepts are unclear to me and I shall be grateful for an intuitive answer:

Q1: In my example, I want to prove if the signal is periodic or not. So something that I want to prove to be true becomes the null hypothesis statement? Thus, would

 H0: the signal is periodic and H1: not periodic?


Q2: I got the value of pval for my signal as 2.3e-6 fmax (the maximum frequency) = 0.0078 andfisher_g = 0.1136. How do I interpret this result? Is my signal periodic or not?

Q3: If the calculated pval` is less than the threshold which usually is 0.05 then we reject the null hypothesis. But in the documentation it is the opposite and the threshold is 0.000001 which I do not know how it has come. I am confused! Please correct me where wrong.

• I’m voting to close this question because this is a statistics question, not signal processing; stats.stackexchange.com might be a better place to ask. – Marcus Müller May 6 at 17:38