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fusion-flap / flap

Fusion Library of Analysis Programs
MIT License
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Feature time frequency #92

Closed martonvavrik closed 2 years ago

martonvavrik commented 3 years ago

STFT algorithm developed and integrated into flap, as detailed in #91

sandorzoletnik commented 2 years ago

Dear Marci,

You did not provide a test program for stft and a function for stft. Please observe that all operations (like apsd, cpds) have a method and a function. The method operates on a data object, the function on a data object in the storage. I have done this. I have also created a mode in TESTDATA which generates a test signal with temporally changing frequency. I created a test_stft function in flap_tests.py. If you just run flap_tests it now tries to test stft with a signal with linearly changing frequency sine wave. I expect to see the temporally changing frequency peak, but I don't see anything. Please pull feature_time-frequency and test.

martonvavrik commented 2 years ago

Sorry, forgot to do it in the summer, but now that you mentioned, I'll check it out. (And also forgot to write the remaining tasks into the issue. Is there anything other in the to-do list in this issue?)

sandorzoletnik commented 2 years ago

Just check why flap_tests does not show what I expect. Maybe I did not use correct parameters, I used defaults.

martonvavrik commented 2 years ago

The STFT works fine, but the given signal's amplitude is around 0.015, and the resulting STFT's max amplitude is around 0.009. If you increase TESTDATA's amplitude (by 100x) it works fine. However that's not a satisfying answer, we should still be able to plot STFT's with small values, so there might be an issue with the image plotter, because the lower limit for the plottable amplitude stays at 1.0.