Is it possible from time domain convert to ωt (x-axis) ?

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I have pressure data and date time in harmonic waveform (image attached)
then by FFT analysis, I obtained the phase difference (radians and degrees), and the amplitude ratio
is it possible to plot ωt on the x-axis?
I can't find an article that discusses something similar.
Does anyone know it?
  1 Comment
Mathieu NOE
Mathieu NOE on 22 Aug 2022
hello
I am a bit surprised how you would compare the 3 signals that have different frequencies (so non constant phase difference ) ?

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Answers (1)

Walter Roberson
Walter Roberson on 27 Aug 2022
ω has units of cycles per second. t has units of seconds (typically). would therefore have units of cycles per second times seconds = cycles. I am having difficult figuring out what that would even mean and what the y axes would be.
I can think of one way that might maybe be relevant. Instead of plotting with as the x axes, you could do a short-time fft (sfft) and plot the frequencies along the y axes and the time along the x axes and the values represented in the z axes (perhaps as color.) In other words, you might create a spectrogram

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