MATLAB (MATrix LABoratory) is a numerical computing environment and a fourth-generation programming language. Use this tag with care.. see excerpt.

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How can I estimate a signal similar to my data using ar modeling in matlab

To be more specific, I have a time series which corresponds to a section from an EEG signal. The idea is obtain AR coefficients and then use these coefficients to create a simulation where I can get a ...
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11 views

Time shift in DWT using Mallat algorithm over the $2^{10}$ scale

I am doing DWT on $2^{10}$ scale using the Mallat algorithm. As I know, DWT using the Mallat algorithm decimate sampling frequency 2 times at every next scale, it means $F_s$ is different for each ...
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1answer
11 views

Do I need an I-Q (in-phase/quadrature) mapper in Simulink with the QAM modulator?

Would it be correct if I use the Random Integer Generator block with a certain $M$-ary number (say $M=16$) followed directly by the ...
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1answer
23 views

How to calculate Long Term Average Spectrum of an audio file?

I'm working with audio files and I have to find their long term average spectrum. Although I had an option available in the software Praat but I don't understand the algorithm of finding the spectrum. ...
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14 views

object selection from an image using watershed

I have already done the thresholding and skeletonising that image for the separation of the fiber.How to separate a fiber from a group of fibers and to find out the length and other properties of that ...
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19 views

Digital filter design [on hold]

While analysing the filter design code in MATLAB , I have encountered the following MATLAB script. ...
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33 views

RLS or another way to solve Ax=b in batches

I need to solve a system of linear equations to do the imaging. My A is 60k by 10k or so and not full-rank. What are the ways to proceed? I tried matlab built-in LSQR algorithm, which allows ...
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0answers
27 views

GCC-PHAT Python

I'm implementing a GCC-PHAT function from matlab to python using this code (as the gccphat function in matlab) : ...
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1answer
17 views

Power/Amplitude Response of a system

I am currently looking over filters and understand the frequency response of a system, e.g. a low-pass filter. However I am confused by the 'Power/Amplitude response' of a system as detailed in my ...
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21 views

MATLAB filters $\tt fir1$ [closed]

I need to remove a PI sound from music ($300\textrm{ Hz}$ & $3000\textrm{ Hz}$ I guess) and I don't how to do it using fir1 filter design. Sound file ...
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1answer
35 views

Wavelet transform in MATLAB

Suppose I have a wave with $20 \textrm{ kHz}$, $100 \textrm{ kHz}$ and $300 \textrm{ kHz}$. Sampling frequency used is $1000 \textrm{ kHz}$. I apply the discrete wavelet transform on the wave like ...
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34 views

Implementing blind deconvolution in MATLAB

I want to implement blind deconvolution for the signal $ r(n) = h(n) \star s(n) + a(n)$ in MATLAB where $r(n)$ is the recorded speech $h(n)$ is impulse response of room acoustics $s(n)$ is desired ...
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24 views

How do we find the Power Spectrum Density (PSD) and which data type is valid for that?

I want a simple explanation on how to find PSD and which type of data (in which units, I mean) can be used for doing so. If found similar interesting questions 1 & 2 and some on Mathworks, like ...
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2answers
19 views

How does MATLAB's $\tt upfirdn$ select extra points when downsampling?

I had a signal 512 samples long and I used upfirdn to filter and downsample it by a factor of 2. I thought this would result in a 256 sample long variable, but ...
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0answers
15 views

Generating discrete filter polynomials in Simulink

I would like to implement some digital filters in Simulink. I tought of using the Discrete Filter block. To do so, I would like to generate the discrete polynomials of the filter with a tool instead ...
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0answers
21 views

Convolution to FFT conversion in Octave/Matlab [closed]

I am trying to replace conv2 and conv3 for fft to speed up calculations in GNU ...
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1answer
27 views

SNR and noise in Simulations

I've always taken the definition of noise and SNR for granted in doing BER simulations in an AWGN channel. I would usually use the AWGN noise function and make a loop with varying SNR values. ...
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17 views

How to calculate Fourier's coefficients of a $T$-periodic function with Scilab?

I have a vector of a size $N>1$ (it represents the values of a $T$-periodic function on a interval). I want to calculate its Fourier's coefficients with the fft, ...
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31 views

How do image resampling in Matlab for panorama stitching?

I am working on Panorama stitching problem (Typically, I follow this pdf: http://newton.uam.mx/xgeorge/uea/graficacionII/Lab4/lab4.pdf) I have implemented everything, and get the homography matrix, ...
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1answer
37 views

Applying a time delay with Z-Transform

I am trying to take a signal $F(t)$ that has been sampled at some time DelT, I then wish to pass this signal through a channel $H(s)$. To do this I am sampling my signal $H(s)$ at DelT time intervals ...
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1answer
32 views

Implementing Welch's method for Power Spectral Density

I want to implement Welch's method for PSD calculation in MATLAB. I do not want to use built in MATLAB cpsd function, such that I can change the FFT implementation ...
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0answers
48 views

Generating LDPC codes of arbitrary sizes in MATLAB

I am having problems generating LDPC codes of arbitrary sizes in MATLAB primarily because MATLAB insists on the parity check matrix that is input into its ldpcenc ...
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1answer
35 views

MATLAB and sampling rate

I have a question about sammpling rate in MATLAB. I read a .wav file using audioread(). It give me sampled data called ...
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1answer
29 views

Which pattern (circle pattern or checkerboard pattern) should be used for automotive camera calibration (fisheye/wide webcam)?

Calibrating a Fish-eye camera / webcam with large angle mounted on car by using opencv 3 One important issue is to define the calibration pattern and its position !!!! The affects error that paly an ...
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0answers
25 views

How to convert a spatial frequency in a 2D-DFT into the units radians per pixel?

Let's say I have a 2D image, and I take the discrete Fourier Transform (via FFT) of that image. In the frequency domain, I get the following image: In this image, let's just assume all the spatial ...
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3answers
61 views

Output signal length after fft

I am trying to understand the functionality of fft.m in matlab . For example: if I input a signal of length $7$, and use the FFT function, the output is of the ...
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1answer
42 views

Frequency response given poles and zeros

I'm trying to plot the frequency response $H(z)$ of given zeros/poles using the following code in MATLAB: ...
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35 views

Why pixels on image edges are shifted when using Wiener filter?

I implemented a Wiener filter using Matlab and i noticed that both functions(mine and matlabs) are creating an image with shifted pixels on the edges. Class teacher said it will happen. Is there a ...
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2answers
37 views

generating white gaussian noise in matlab using two different functions

I want to know the difference between the two Gaussian noises generated below? Which one is white and how can i make the other one white? y=wgn(1,10000,0) and ...
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1answer
22 views

Explain how to apply Hanning window to Fourier amplitude spectrum

This example code was used to answer a question about applying a window on the Fourier amplitude spectrum. How to apply Hamming Window? I have a question about the section of code related to the ...
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1answer
37 views

How to overlap and add the frames after applying some modification in time domain

I am trying to apply Dynamic range compression (DRC) in time domain in MATLAB. But I am having problem in overlapping and adding the frames. Here is my work: ...
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1answer
71 views

Obtaining the FFT of a data set collected through an accelerometer

I'm using MATLAB to analyse a very large sample of acceleration data collected using the MPU9150 IC. My aim is to plot the FFT for this large sample of data. The daya is of three axes; $x,y,z$ and I ...
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1answer
44 views

Difference between fft(signal, nfft) and fft(signal)

I want to know the difference between these following commands (matlab) and why I get two different outputs? fft(signal); fft(signal, nfft); I found that ...
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1answer
39 views

What could be causing these humps every 10 Hz on my PSD estimate data?

I am working with EEG recordings about 1,000,000 data pts long, recorded at 4,000 Hz. I'm generating PSD estimates for these recordings using the matlab "periodogram" function like so: ...
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2answers
72 views

Problem with Generalized Cross Correlation (PHAT filter)

I have to calculate time delay between two signals.I am using the GCC-PHAT method. First, I cut the signals into smaller parts (~0.5s) and then try to calculate the delay. When I display those two ...
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2answers
34 views

Bandpass Filter Order vs Sample Numbers of Noisy Signal

I'm working on signal filtering in MATLAB. i wrote sample code that generate 50 Hz signal with some noisy frequency and use Kaiser bandpass filter to get only 50Hz frequency. this code work great! but ...
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1answer
38 views

Noisy signal filtering matlab

I'm currently working on rectifying a respiratory noisy signal shown below: I've already tried to filter the noise as you can see in the image below (full image): The red one is the noisy signal ...
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1answer
69 views

Plotting Power Spectrum (Matlab)

I want to make a plot of the power spectrum for a .wav sound file, over the frequency range from -2000 to 2000 Hz. Attempt: I used the following code, but the resulting plot is one sided. It doesn't ...
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1answer
23 views

Designing a root-locus compensator to attain design requirements

I am working with Matlab to design a compensator capable to make a system attain the design requirements ($\omega_n\geq 0.3$ rad/s & $\xi\geq 0.5$). In order to do so I have a discrete-time ...
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2answers
63 views

Filter Design in Matlab

I want to design a filter to remove all frequency components from a .wav file except those within $\pm 25\,\text{Hz}$ of $523\,\text{Hz}$ as well as its harmonics (up to the Nyquist frequency). ...
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1answer
54 views

How to shift a signal to the center of the frequency domain?

Let's assume I have a 1024 x 1024 matrix that represents the spatial domain. After I perform a FFT and center the frequencies, I get the a signal that looks like the following in the frequency ...
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0answers
18 views

Should S-Matrix components for scattering response in a Polarimetric Radar be Real or Complex?

I am trying to implement some polarimetric decomposition algorithms on my MIMO polarimetric radar. At first, I will try the Pauli Decomposition algo. But instead of doing signal processing on the ...
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0answers
23 views

Simple sample and reconstruction code - MATLAB

I am trying to go from theory to code. I take x (let say 16KHz is continuous time) then I sample it in 2Khz So I do ...
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1answer
28 views

How to extract pixel-specific time-stream from mp4 video

I am interested in extracting specific timechange information from an mp4 1900x1200 20fps video.The only pixels I want to process can be found in its borders. Therefore I only need to process ...
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23 views

Weibull fading channel

As explained here for Rayleigh fading channels, can anyone help me arrive at similar equations for finding fading gain ...
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1answer
50 views

how to extract pitch contour of a speech by matlab?

I am totally new in Matlab. Can anyone please explain in details how I can extract pitch contour of a speech? I would like to observe how the speaker's pitch varies during his speech to know whether ...
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0answers
28 views

FIR anti aliasing filter design

Suppose we have a signal with a $3\mathrm{kHz}$ bandwidth and a sampling rate of $48\mathrm{kHz}$. Then we want to decimate ($6$-rate decimator) it, in which the decimator has a passband ripple of ...
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1answer
38 views

Filter Design near Nyquist frequency (complex curve fitting)

I'm fitting IIR filters to a complex transfer function with Matlab's invfreqz.m. My fitting results are very good, but when I come very close to the Nyquist frequency the phase response runs to 0 and ...
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2answers
41 views

Finding Argmax in MATLAB [closed]

I have a Gaussian random variable $z$, whose mean $\mu$ and variance $\sigma^2$ are functions of two variables $x$ and $y$. Is there any way in MATLAB so that I can find the values of $x$ and $y$ for ...
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2answers
23 views

MATLAB: get members of histogram populations EXCLUDING those inbetween

The Problem I have a (noisy) square wave signal and need to extract the data points that make up the 'baseline' and 'plateau' ONLY. I do not want data from the rise and fall. So far I have ...