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Questions tagged [phase]

phase is angular shift between periodic signals.

phase is angular shift between periodic signals

  • for example signal x1(t)=cos(t) is the same as x2(t)=sin(t+PI/2)
  • angle PI/2 is the phase (angular shift) between sin(t) and cos(t)
  • phase is also used as angular coordinate for polar representations of phasor commonly used in electrical engineering
  • phase distortions of signals are called jitter
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QPSK function operation/MATLAB

QPSK Modulation its supposed to use 2 bits for each symbol, but wheter I use pskmod or comm.QPSKModulator, I'm still getting the same amount of symbols as bits. Am i doing something wrong? Is something wrong with the function? Thanks in…
Bryan Carrión
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Generating K-space from magnitude and phase

My question might be simple but I really need to make sure that the process I am doing is valid. The MRI scanner acquires k-space data, S, and then takes 3D inverse Fourier Transform to reconstruct the actual image in the spatial domain, which is in…
SaraG
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How does one obtain the lavfi.aphasemeter.phase frame metadata in FFMPEG?

I'm trying to derive the numeric representation of a sound file's phase. FFMPEG's aphasemeter filter seems to fit the bill for computing this number; the docs explicitly say: The filter also exports the frame metadata lavfi.aphasemeter.phase which…
jsamsf
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How to find the bin number of the frequency of interest from an fft signal in python?

I am doing a task which involves taking two signals from a phase doppler anemometry system and calculating the phase shift and the frequency which will further help in finding the velocity and diameter of the droplet. Before getting into the actual…
Vishvachi Sinha
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Divide complex Mat with real Mat in OpenCV

How can I divide a complex Mat with a real Mat in OpenCV? I want to calculate cross-power spectrum for phase correlation but I get a runtime error when using divide. Update I figured out a way to calculate cross-power spectrum but i don't get the…
user8254410
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apply fourier shift theorem to complex signal

Im trying to apply the fourier phase shift theorem to a complex signal in R. However, only the magnitude of my signal shifts as I expect it. I think it should be possible to apply this theorem to complex signals, so probably I make an error…
Leo
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Weired values for FFT of falling saw-tooth

I'm trying to get the amplitudes and phases of a (falling) saw-tooth signal. My saw-tooth is 1024 samples long and generated as int numSamples = 1024; for (int i = 0; i < numSamples; i++) { samples[i] = -((float)i / (float)(numSamples - 1) *…
Lenny
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Python 'Assertion Error (depth == CV_32F || depth == CV_64F)'

I have a problem with the cv2.phase() function. I coded the following: img = cv2.imread("1.jpg", 0) cv2.imshow("image", img) img_dx = cv2.Sobel(img, cv2.CV_8U, 1, 0) img_dy = cv2.Sobel(img, cv2.CV_8U, 0, 1) angles = cv2.phase(img_dy, img_dx) and…
Lars_R
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Does an equivalent transformation of a signal to a spectrogram image exist in which the phase information is part of the resulting image?

I'm working on a research project where we would like to apply convolutional neural networks to an image representation of a signal. However, it seems that if I would use a spectrogram, I would end up loosing the phase information. As a result, my…
Maxime Leclerc
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Phase Difference Between Two Sine Waves With Same Frequency

I have two vectors that represent two different signals, each being a sine wave with the same frequency. I've tried cross-correlation, Fourier transforms, Hilbert transforms, etc, but nothing returns the correct, theoretical value (in radians) at a…
Jacob G.
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Cannot read property '$$phase' of null - AngularJS

for some reason I get this error while splicing an object from an array that lives in the $scope: Cannot read property '$$phase' of null here's the code: $scope.deleteThis = function (index) { $scope.$parent.accounts.splice(index, 1); …
Pistolpete .
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2D FFT: Identify connection between certain frequencies in an image

Imagine you have a real image, and you put it through a 2D FFT. Usually this yields a cross-like structure (edge effect) and some real content, depending on the image. Imagine the original image contains two spots with bad lighting, which for…
PhreakShow
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Matlab Simulink Simulation Time

I am using Simulink from Matlab. When plotting anything the Simulation Step Time is extremely slow. How can I change the step time in settings. I have tried a lot but I don't understand the settings pretty much. Update: Phase Locked Loop
Tes3awy
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MATLAB angle() to C# conversion

I want to transfer to C#, a function that computes the phasor angle of an expression from MATLAB, angle(). I found that angle(x+yi)=atan2(y,x) but here comes my problem, I have a square root that depending on the values I give it is either positive…
hey
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RENDER_RESPONSE takes to long in seam

I write application using JBOSS Seam with Richfaces. Unfortunately some pages of it load very long especially when I want to show about 100 rows (or more) in table . Getting response from database takes about 2453 ms, so it is quite well. However…
Fryta
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