How to calculate Harmonic distortion

Good afternoon everyone.

I have measurements made of acceleration and other variables on three axes coming from a sensor (accelerometer and gyroscope).

I do data acquisition through LabView and I will do the data processing with MatLab.

I'm saving the files in .txt, and now I want to open that file and process the data.

I want to do the harmonic distortion, and find the specific harmonic. I've seen some codes about harmonic distortion but they all use functions to build the wave, but I have data from my measurements. I don't know if I managed to explain myself correctly.

Thank you.

[Mathieu NOE]

hello Ricardo

this is a first script to do fft and spectrogram analysis; there a 2 options to open wav or txt files (I like the readclm function for that)

then we can build on this to then calculate both the total distortion attenuation (in dB) and the total distortion factor (in %). The thd function is included in the signal processing toolbox in Matlab.

%% Calcs

% THD with 5 harmonics including fundamental

nharm = 5;

Total_Distortion = thd(data,Fs,nharm);

Total_Distortion;

% THD factor in percent

Total_Distortion_Factor = 100*10^(Total_Distortion/20);

regards

[Ricardo Rebelo]

the scrip is the simple demo ?

I need to add to the simple demo script, the thd function:

%% Calcs

% THD with 5 harmonics including fundamental

nharm = 5;

Total_Distortion = thd(data,Fs,nharm);

Total_Distortion;

% THD factor in percent

Total_Distortion_Factor = 100*10^(Total_Distortion/20);

?

Thank´s a lot

Best regards

[Mathieu NOE]

hello

yes , simly use the THD demo code above within my code - or separately, as you prefer