Questions tagged [Fourier transformation] (20)

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Butterflies in Fourier BP?

Please tell me what it is? I understand it is a display of one of the FFT algorithms? Can you tell which one? Heard about the decimation in time and frequency, what of them?
Allene.Prohaska69 asked March 31st 20 at 20:07
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How to make a window a bandpass filter?

Hello. There is some complex signal. There is a lot of frequencies (from 0 to 100, for example), this can be obtained by using the Fourier transform. But you want to keep only certain frequencies (e.g. from 10 to 50) and bring the signal back but with these specific frequencies. Tried to do a Fourier transform, zeroing out...
heloise.Okuneva asked March 23rd 20 at 18:37
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How to improve the tone of the voice without increasing the speed (e.g., as in-app Talking Tom Cat)?

Stumbled upon the the app Talking Tom Cat — cat Android on the screen and listens to the microphone and if to say something, he repeats this phrase, but increases the tone of the voice. It's fun "cartoon" voice, like the chipmunks. The obvious way to achieve this is to play audio a little faster, but then increase the tempo...
eleazar_Terry10 asked October 3rd 19 at 13:27
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The question on the harmonics in the EEG signal?

Hello, tell me stupid... If psle preobrazovaniya Fourier, complex signal (the EEG) in the spectrum has peaks 70, 140, 280 Hz... we can assume that the main axis 70, and further is it a harmonica? Question these garmoniki, what is it? We can say that there is a frequency generator 140, and 280, but they usileny the fact that...
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Why hardware FIR filters (FIR filters) are doing the FFT?

Probably a very stupid question, but the direct answer I never found. For example given the task to design conveyor hardware FIR filter (FIR-filter), for example on 1024 points. Why usually do it using FFT (Fast Fourier transform, FFT), and not in the forehead by the formula of convolution? It would seem each successive ste...
Kasandra79 asked October 3rd 19 at 02:40
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How does the FFT filter in the software MaxImDL?

How does the FFT filter in MaxIMDL when processing astronomical images? Give Recommendations for use. Thanks in advance.
Guillermo.Schuppe83 asked September 30th 19 at 17:40
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How to find the average value of the signal modulo the discrete Fourier transform?

The image of the DFT module, you need to find the average value of the signal.
Margarette_Fahey asked September 20th 19 at 00:48
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Are there any good ways to recognize whether the chord played on the guitar?

The problem is: there is a guitar and a set of pairs (string, fret), which must be played simultaneously(a chord). And need real-time to determine whether the chord played. That is, the program gets the fingering of a chord and continuously "listening" record from microphone near the guitar need to tell that this chord was ...
enrico asked September 18th 19 at 14:45
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How to divide the "peak" functions on two simple peak?

Good time of day. Sorry for the trivial question. Must be hard in University with mathematics, especially functional analysis. There are experimental data points on which the graph that do not have at this stage of the analytical formula. For example Suppose that the initial "peak and shoulder" function is a superposition o...
taylor0 asked September 15th 19 at 22:37
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How to invert the frequency spectrum of the image?

What happens if you flip the frequency spectrum of the signal of high frequency will become low and low - high? Not very versed in the mathematics of signal processing. In General terms, imagine what the Fourier transform is, and what is the frequency decomposition of the image.For audio signal, as I write, it is a trivial ...