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Questions - fft

FFT outptut for a signal with 2 cosf() cycles

I am transforming a signal using the ZeroFFT library. The results I get from it, are not what I would intuitively expect. As a test, I feed the FFT algorithm with a buffer that contains two full cycle...
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Bram

fft

waveform

frequency-analysis

Votes: 0

Answers: 1

Latest Answer

Windowing causes some spectral leakage. Including the window function, the wave now looks like this: If I feed it a buffer with exactly 2 cycles of cosine, wouldn't the Fourier transform result in a...
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harold

How to detect time-periods present in a signal using FFT?

I'm trying to determine the periodicities present in a given waveform. This is my signal, which is a sinusoidal waveform: t_week = np.linspace(1,480, 480) t_weekend=np.linspace(1,192,192) T=96 #Time P...
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EnigmAI

python

numpy

scipy

signal-processing

fft

Votes: 0

Answers: 0

discrete cosine transform implementation differs from library function

I've implemented my own DCT function, but the output differs from scipy's fftpack dct function. I was wondering if anyone knows whether fftpack.dct( ) does any additional transformations, and if so wh...
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Rahel Miz

python

image-processing

scipy

signal-processing

fft

Votes: 0

Answers: 1

Latest Answer

The scipy.fftpack.dct performs the 1D dct transform whereas you implemented the 2d dct transform. To perform the 2D dct using scipy use: X2 = fftpack.dct(fftpack.dct(data, axis=0), axis=1) This shoul...
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Tomer Geva

Android Kotlin Real-Time FFT and plot

I am trying to apply Real-time FFT on a sensor data which is connected over the bluetooth BLE. There is a sdk which allows you to receive the data from the sensor in the Android using handler. I am us...
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Greyfrog

android

kotlin

fft

android-graphview

Votes: 0

Answers: 0

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