Harmonic Distortion

[RicardoRebeloo1]

I'm taking measurements of acceleration, and I'm saving that data, and I also make graphs in real time. I want to do the harmonic distortion, but the functions I have to do require an input from a signal and I only have the output of my graphics.
Someone can help me ?

Best regards 

My output :

The function input:

[paul_cardinale · Accepted solution]

It took me a while to find it:

Functions -> Express -> Sig Manip -> To DDT

[RicardoRebeloo1]

Thank you very much, I think I managed to do a part of what I wanted.

[RicardoRebeloo1]

and this case:

[RicardoRebeloo1]

i make this: