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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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What do the Contour Levels Produced by Matlab Function Contourc Represent

I have been trying to understand what the contour levels are. As far as I understand a contour of the function $Z(x,y)$ is a set of points in the $(x,y)$ plane, such that $Z(x,y)$ is fixed at some ...
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31 views

How to compare multiple polynomials in MATLAB?

I am trying to fit a second order polynomial to various curves on a binary image using MATLAB polyfit function.There are many such curves on the image, and the ...
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1answer
11 views

Removing lines of certain length from an image in MATLAB

I want to remove the portion of the line (highlighted by the yellow circles) where pixels form a straight vertical line segment. If I use the strel ...
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8 views

Average around pixel clusters

Im looking to replace the values of pixels / pixel clusters in a greyscale image with the average of the values of their boundaries. Suppose the greyscale image is given by $I$ and the pixels to ...
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is discrete wavelet transform (DWT) appropriate to detect and calculate noisy shear wave arrival time? [on hold]

what is suitable command in (DWT) that can be use to detect specific point like attached figure
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9 views

Readjusting the LSB encoded pixels in Edge Adaptive Steganography

I have two pixels generated using LSB encoding $(x_{i}^{'}, x_{i+1}^{'})$. However, there are chances that either one of them, or both, lie outside the range $[0, 255]$ or $|x_{i}^{'} - x_{i+1}^{'}| &...
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38 views

IIR design with Yule-walker method (or equivalent) in Python

I would like to design an IIR from an impulse response (find optimal coefficients), and I want to do it with Python. With Matlab we can use the Yule-Walker method (yulewalk function in Matlab signal ...
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48 views
+50

How to calculate Total Variation (TV) of two images?

I try to implement Differential total variation (DTV) as described in (Wu, Y. et al 2017) or (Li, Y. et al 2015) to find the similarity measure between two images. (Li, Y. et al 2015) describe DTV as ...
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27 views

Matlab code for LDPC code with rate othern than 1/2 [on hold]

I need a matlab code to simulate LDPC encoder and decoder for a rate other than 1/2. The code length should be $N=128$. Can anyone help? Thanks in advance.
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1answer
23 views

Entropy of an image with equalized histogram

Let's suppose we have an image and perform histogram equalization on it. Would the entropy of the resulting image be lower, higher or equal than the entropy of original image? At first I tought that ...
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33 views

Get variance of white noise from Accelerometer data

i have a static accelerometer data. So i assume that all signal are from noise. So i model it like this, $$X(k) = X(k-1) + U(k)$$ But I plot the $U(k)$ autocorrelation function seems it is not white ...
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47 views

FFT of a $N$-length real sequence via FFT of a N/2-length complex sequence

I would like to optimise FFT algorithm by only using a FFT of size $N/2$ to transform a real sequence of length $N$. There are already many questions and many excellent answers on the matter (here for ...
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14 views

librosa vs matlab stft outputs

I'm generating STFT features using librosa.stft() and MATLAB's spectogram(). But, I'm ...
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2answers
41 views

About the BPSK signal waveform

My basic knowledge is too bad. I am confused about the waveform of BPSK signals. To create a BPSK signal, I generated BPSK symbols with ideal rectangle pulse shaping, which is given by: Then, the ...
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1answer
25 views

What is wrong with my residue partial expansion method? (Transfer Function into State-Space Modal/Diagonal Form)

I'm using reference from here and here. This is Laplace transfer function of DC Control Speed System: $$\frac{\omega(s)}{V(s)}=\frac{K}{(Js+b)(Ls+R)+K^2}$$ Where, $\omega$ is the motor angular ...
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27 views

Extracting individual frequency components from FFT

I have an audio file with two different tones in it. Using the FFT function in MATLAB I plotted the FFT magnitude, and as expected the two separate frequency components are present. How do I extract ...
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21 views

Is it possible to zero-pad series when using MSCOHERE in matlab?

The function fft allows one to zero-pad, and mscohere, after all works with auto and cross spectra, which, presumably, have all been calculated with fft. I haven't found any mention on zero-padding in ...
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17 views

Implementing 1-D Wavelet transform in MATLAB

I am trying to implement 1-D CWT on a Tiva-C board. To understand the CWT I wrote a simple MATLAB code without using inbuilt functions. I am getting some results but they do not match with the results ...
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12 views

Difference between power spectrum of NR signal as seen in Vector Signal Analyser and MATLAB pwelch method

My setup is as follows: I have an R&S SMW signal generator which generates a 100 MHz 5G New Radio signal. The signal is passed through a channel emulator which has components like Digital-To-...
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1answer
27 views

What is the proper way to implement a real time spectrogram?

I am trying to implement a real time spectrogram and I am not sure that I am implementing it the right way. First I decided to use Matlab, I was taking a short recording of lets say 0.1 seconds and ...
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1answer
129 views

How to remove ECG artifacts from EMG data?

I'm new to signal processing and try to analyze EMG data from pectoralis major and other respiratory muscles. Unfortunately, there are strong ECG artifacts in all recordings and I don't know how to ...
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1answer
30 views

4-phase FIR LPF in MATLAB

I'm trying to create a low pass FIR filter using the coefficients I found in ITU 1770-3 on page 18. This is the last piece of the puzzle for an audio loudness metering algorithm I'm working on. I'm ...
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15 views

Integrating values in a matrix in MATLAB- Audio Loudness Meter

I'm trying to implement an algorithm in MATLAB as specified by ITU-R BS.1770-3. The goal is to measure loudness of an audio file in 3 different ways: un-gated LKFS, gated LKFS, and true peak. So far I ...
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27 views

Filtering Audio Signals in MATLAB

I'm trying to apply a filter to an audio signal in MATLAB and having some trouble processing it. So far, I have a transfer function that describes a K-weighted filter, and I am able to create a bode ...
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23 views

Amplitude from MATLAB periodogram()

i've got two questions about the matlab periodogram function: How can I recover the amplitudes from the periodogram? ...
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41 views

Weird features mismatch using SURF

I'm trying to use SURF to detect an object (particularly a cur number plate) in another image. After unsuccessfully trying to use OpenCV i have moved to MATLAB. Everything works perfect on MATLAB's ...
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How do MATLAB and/or Python treat $2^n$ samples rule in FFT

As far as I have read, an FFT requires that the number of original data points must be a power of 2. I'm wondering whether the tools like MATLAB or Python which have FFT functions take care of this ...
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49 views

Resampling power spectrum from linear to logarithmic axis

My question is whether there exist methods for resampling a signal (power spectrum) from linear to logarithmic spacing without loss of information. My ultimate goal is to smooth spectra such that low-...
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19 views

how to robustly estimate low and up envelope of signal with trend, few level constant steps and noise

I am looking for robust estimation method of low and up envelope of the signal consisting from smooth trend component, constant steps between few fixed levels and additive noise (+ outliers of course)....
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12 views

Decoding for punctured convolutional encoder

I have 1/2 rate convolutional encoder which punctured to rate 3/4. The puncture pattern used is [1; 1 ;1 ;0 ;0; 1] . How to decode these punctured sequence using hard decision viterbi decoding? Can ...
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2answers
56 views

Negative Signal to Noise Ratio

What is the reason for getting negative snr value when calculating Signal to noise ratio of speech signal using matlab function SNR()?
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21 views

Difference between these two integrators

I am an electrical engineering student but new to digital signal processing. However while searching references for my senior project I came across following two different discrete integrator blocks ...
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90 views

How I can perform SIMO channel convolution in MATLAB

In OFDM system, I need to transmit a signal $x$ in SIMO channel $H$ of single Tx antenna and $4$ Rx antennas. The initial equation for that convolution is $r = Hx + n$ where $n$ is the noise. As ...
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22 views

What are the best resources to learn feature extraction and classification of signal?

First of all, forgive me if I am posting anything wrong; I am new here. I need to learn signal processing like feature extraction and classification for my final year thesis. I asked some persons and ...
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71 views

How do I extrapolate a 1D chirped signal?

Following a past question, I'd like to extrapolate a signal like the one below: (red is signal, blue is the the extrapolated ) ...
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1answer
30 views

position of a signal in a vector [closed]

I have 4 signals: $z,c,d$ and $r$. $r$ is defined by: $r=[c,z,d,z]$ I would like to find signal $d$. In Matlab I do this: ...
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81 views

Detecting fundamental zero crossing point

I am looking for ideas from the more experienced members on algorithms for determining the fundamental zero crossing point of a 50 or 60 Hz signal. The fundamental zero crossing point is then used as ...
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33 views

MATLAB reduction of trends in xyz-data

I have a lot of xyz-data arrays of the size 121 x 161. This is one example: So, I need to calculate means and trends. I am new to Matlab, so I tried to import the data via: ...
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Is there a best way for processing a multi-direction offset GLCM feature?

I'm working on a project on neovascularization classification. Where I'm using MESSIDOR database for my project. For classification, I'm using both GLCM and GLRL (by Xunkai Wei, link) for my ...
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33 views

Is there an equivalent to MATLABs zplane-function in python?

Does anyone know of a valid equivalent to Matlabs zplane function? In Matlab, it can be used to both create a pole-zero-plot and also to get the poles and zeros of a system described by its ...
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Question about Fourier descriptor and the physical meaning of the coefficients

I would have some questions about the Fourier descriptor and the physical interpretation of the individual coefficients. I'm rather new to this concept, so I would be looking for a simple answer. To ...
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how to use generalized Hough transform for 2d boundary matching

I'm a beginner working on the pattern matching. I would like to use the generalized Hough transform(GHT) for shape matching based on the boundary of the object. for example, if I have 2d coordinate ...
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1answer
58 views

estimate the impulse response after equalization

I want to estimate the impulse response of the channel at the receiver. Assuming some arbitrary impulse response: h=[1 0.2 -0.4 0.0 0.6]. Once the equalizer is ...
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1answer
27 views

how to extract a period of a periodic pulsed signal?

I rercorded a sequence of zeros and ones which is repeated many times. However, the first and the last repetitions may not be complete because I have to start recording at a random time, so the ...
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2answers
91 views

FFT vs DFT Run Time Comparison (Complexity Analysis) in MATLAB

So we were given an assignment to plot the time taken by the FFT algorithm by MATLAB and a DFT algorithm written by me in MATLAB.G The expected output should have been the DFT algorithm following the ...
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1answer
50 views

Problem with 1st order Massberg LPF [duplicate]

I'm trying to implement this filter in title by following the book "Designing Audio Effect Plug-Ins in C++" By Will Pirkle Problem I'm facing is the magnitude response error when comparing against ...
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1answer
28 views

Reproducing paper results about a wavelet transformation using python [closed]

I have been reading this PhD theis about wavelets and I am trying to reproduce some of the results but I don't know the specific code to use to generate similar results. The original time series ...
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1answer
50 views

Design 2nd order sections IIR filter for high orders (more than 500)

I am currently building a Reverb that needs to fit on a DSP. I am using the model proposed in this link https://ccrma.stanford.edu/~jos/pasp/Freeverb.html. It involved to create some Feedback Comb-...
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38 views

trying to understand fast fourier transform in matlab

Y = fft(X); P2 = abs(Y/L); P1 = P2(1:L/2+1); P1(2:end-1) = 2*P1(2:end-1); 1) I dont understand what lines 2-4 are acheiving, why must lines 2-4 be ...
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94 views

Generate Complex White Gaussian Noise in MATLAB

n_3=sqrt(0.1)*randn(1,K); n_4=sqrt(0.1)*randn(1,K); beta_NLoS=(n_3+1i*n_4); % CN(0,0.1) I want to create a $CN(0,0.1)$,does my code have any problem?