How to analyze phase of a FFT signal?

I have gathered phase of frequencies of FFT signal. The top left chart has been created for data collected while the device was working appropiately. Then the device has been damaged to simulate different kinds of exploitations. The rest of the charts has been created after damaging the device. How should I analyze this data? I want to find any information about possible damages based on the chart. X axis is Frequency[Hz] and Y axis is Phase[rad]

[David Goodmanson]

Hi Dominik,

Correlation coefficients might be a possibility, which you can obtain with 'corr'.

[Dominik Stolarz]

Hi David, thanks for answering, i'll get back with the results

Answer 1

[Dinesh]

Hi Dominik,

There are many statistical measures that can be used to analyse the relationships. Some of them are.

1. Correlation coefficient: quantifies the degree of association between two variables.
2. Covariance: measures how much two variables change together
3. t test: a statistical test used to determine if there is a significant difference between the means of two groups

Please refer to the following MATLAB documentations for more examples and details

1. https://www.mathworks.com/help/matlab/ref/corrcoef.html
2. https://www.mathworks.com/help/matlab/ref/cov.html
3. https://www.mathworks.com/help/stats/ttest.html

Hope this helps!

Thank you.