How to interpret the image made by using FFT function directly
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For this kind of picture, I'd like to know what it means. I just import a column of data into Matlab, make this column as X, and then directly use y = FFT (x); plot (y) to get the image
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Ameer Hamza
2020-9-28
编辑：Ameer Hamza
2020-9-28
Generally, fft of a real-values vector contain complex values. When you directly use
y = fft(x)
plot(y)
It just plots real components (x-axis) against complex components (y-axis). I am not sure if this gives any useful information. The usual way is to plot the abs() of the fft vector which gives information about frequency response.
y = fft(x)
plot(abs(y))
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2021-8-20
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