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Bug 3169 - spectrogram power does not match with signal amplitude

Status NEW
Reported 2016-07-28 17:58:00 +0200
Modified 2016-07-28 17:58:58 +0200
Product: FieldTrip
Component: specest
Version: unspecified
Hardware: PC
Operating System: Windows
Importance: P5 normal
Assigned to: Roemer van der Meij
Depends on:
See also:

Danial Arabali - 2016-07-28 17:58:58 +0200

Created attachment 806 simulate sinusoid and plot the spectrograms with hanning and multitapring methods Hello, I was trying to figure out the unit of the power in spectrograms. So I made a sinusoid with a certain amplitude and frequency and then plotted the spectrogram with two methods: hanning and multitapering. I expected that power should be close to the squared amplitude of signal but with neither methods I got this! So, I suppose there is some kind of normalization going on inside fieldtrip which I do not understand, therefore I can not proceed with other kind of analysis if I do not know what are the values I get from spectrograms. I attached the script I used for producing sinusoid and plots. By the way, there is another post in the following link which raised the similar issue but unfortunately there was no answer to it: Thank you in advance for clarifying this issue. Best, Danial