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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Matlab: Conceptual issues on correlation and its analytical expression

Let x = [1 0.9 0.1 -0.3]'. The formula for Autocorrelation is E[x*x'] which should give a vector of mean values. The ...
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Matlab: Issue time lagged time series

My data $Y$ is the output of an autoregressive model of order $p = 2$ excited by Gaussian white noise of zero mean. $y_t$ is a vector output of the AR process: $y_t = 0.195y_{t-1} - 0.95y_{t-2}$ $t$ ...
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1answer
22 views

What is the rms value of a signal and how to use it

In some papers/books I found infos about a signal given as RMS value. What is the RMS value and what information does it contain? How can I compute it? Moreover, if they say that the signal is a ...
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13 views

How to, efficiently, identify telephone number from the key pressed data audio file?

A very common homework question. You are given an audio file(.wav) which has the recording of the keys pressed during a telephone call. You have to identify the telephone number from this audio file ...
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1answer
18 views

Is magnitude information enough to reconstruct an audio signal

I have used an MMSE STSA estimator to obtain the magnitude of an audio signal. The original signal is combined with white noise and I used an algorithm given in an old research paper by Ephraim and ...
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20 views

Mind helping me understand what this matlab code is doing? is this a PSD? or FFT?

I'm trying to learn how to get a useful frequency response of a single plucked string on a guitar. I have some old code that I'm working off of... It works in that i get a spectral response, but i ...
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1answer
12 views

modified Bessel function for Speech enhancement Using MMSE in matlab

I am trying to implement an algorithm proposed in an old research paper by Ephraim and Malah for my DSP course project. I hope someone can help me with this difficult question. For the clean signal ...
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1answer
31 views

Matlab: How do I implement the Expectation operator for time series

I have the output of a time series y(t) which is a vector for t = 1,2,...m denoting the number of data points. Q1: If ...
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1answer
25 views

Calculate properties of a given Modulated Signal

I'm having a hard time trying to understand signal modulation graphics and how can I calculate/find the properties of the signal. The properties I'm talking are: Max. amplitude Carrier frequency ...
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1answer
33 views

digital butterworth filter design error

I am trying to design a digital butterworth filter for the given specifications.. code is posted below.. rp=3; rs=15; FS=1; wp=0.5*pi; ws=0.75*pi; pwp=2*FS*tan(wp/2); pws=2*FS*tan(ws/2); ...
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21 views

how to code fir filter in matlab using discrete equation?

I want to design a fir filter in matlab using the discrete equation. I won't be using any built in functions. For doing so what will be the coefficient? How can i compute it?
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1answer
137 views

Is it necessary to downsample data for filtering of low frequencies?

My data is sampled at $f_s = 32kHz$, and for a particular analysis I'm only interested in signals with certain frequencies from $f_{highpass} = \text{0.1Hz}$ to $f_{lowpass} = \text{300 Hz}$. When I ...
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1answer
77 views

Question on Chebyshev filter

What does the output signal look like when you insert $2000 Hz$ square pulses to chebyshev filter with parameters: (Matlab syntax). I tried to do it like this but I don't understand where it goes ...
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2answers
48 views

How to design a filter with custom group delay — why is it an IIR?

Say I have an FIR filter with desired magnitude characteristics. I could imagine using an allpass IIR in series with the FIR to alter the group delay characteristic to provide both a 'magnitude ...
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16 views

Wave-time trace to Amplitude and PSD spectrum

For a project I’m currently working on, I composed a irregular ocean wave (function of time) by the summation of n regular waves. For the validation and further processing I’d like to produce the ...
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26 views

Generate band limited white noise to be used as excitation in ODE

I am trying to repeat an example I found in a paper. I have to solve this ODE: $25 \ddot{x} + 15 \dot{x} + 330000 x = p(t)$ where $p(t)$ is a white noise sequence band-limited into the 10-25 Hz ...
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25 views

Problem in Implementing Cyclostationary Feature Detector in Matlab

I have Implemented this detector in AWGN channel in Matlab but I am getting vague result. As it performance doesn't vary with change in SNR. Its very strange result for me. I don't know what mistake I ...
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2answers
58 views

Head detection using HOG and SVM

I am currently trying to detect heads in a sequence of real-footage images and am using HOG feature descriptor and SVM as classifier. Currently I am using Dalal's HOG implementation code in MATLAB ...
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1answer
41 views

what method for thresholding?

I want to do one threshold method on high pass components of a wavelet frame decomposition approch,for edge detection in image. I have 14 high pass components. for thresholding, I need keep the ...
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2answers
41 views

Why is my discretized transfer function unstable when my discretized state-space model is stable?

I am working with a 30-state, 14-input linear model that is described by a state-space model: model_state_space = ss(A, B, C, D); The model is extremely slow (it ...
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11 views

Taking a special image derivative using convolution

Could someone help me with the question posted here, which I posted in stackoverflow. I should have posted the question here in the signal processing.
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23 views

Basic Fourier Transform filtering and LTI frequency response using Matlab

Not sure if this is the right place to ask... I'm new to Matlab for LTI signal processing and wondering if anyone can help with something that I'm sure is meant to be basic. I've spent hours and hours ...
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Looking for project ideas based on medical image processing [closed]

I'm a final year biomedical engineering student and I need to look for a few project ideas based on medical image processing. The only problem is, I've been asked to find projects that are not solely ...
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1answer
54 views

Is it possible that adding noise to a signal can increase detection possibility?

I am simulating a feature detector in noisy environment which consist of AWGN Noise and Impulsive Noise. But I am getting a strange result as Signal with Impulsive+AWGN noise has better detection ...
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1answer
46 views

Convert a 1D array into a 'rotated' 2D matrix

simply put, let's say I have this array - [1 2 1] I want to try and get this output in Matlab [1 1 1 1 2 1 1 1 1] It's like my array was 'rotated' ...
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32 views

Generate a surface (3d) plot with a 2d data

I have a 1-d data of light intensity along a line that follows a gaussian pattern. Now, I want to convert this 1d gaussian data to a surface gaussian plot.How do I do that? The intensity line profile ...
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21 views

High error due to resample function in MATLAB

I am working on training the output of the wavelet transform of a signal using a neural network in MATLAB. So I decided to use 3 layer ...
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1answer
100 views

How to take the FFT in a limited range of frequencies?

When using the fft function in Matlab to take the Fourier transform, one can specify the number of FFT points, nfft, and the ...
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1answer
37 views

range and motion in received signals by radar

I've got two signals which are consecutive received signals by a radar system. the signals values are complex (in form x+iy). I have generated a trasmitted signal using the info available. Now, I ...
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49 views

Image super resolution algorithm in Matlab

I'm trying to implement a simple Image super resolution algorithm (DWT-Based Resolution Enhancement ) in the following paper http://www.ripublication.com/aeee/52_pp%20%20%20405-412.pdf I tried to ...
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28 views

Fingerprint minutiae matching

I am working in a fingerprint recognition project using C code running on embedded system. After processing the fingerprint image, I have the minutiae now. I tried to matching two sets of minutiae by ...
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38 views

FFT signatures of QR codes

QR codes have three finder patterns at the edges (See image here) These patterns are inserted to enhance the detection of location of the code on a comparatively larger image. They produce some ...
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1answer
22 views

the phase spectrum of a zero-phase wavelet is not zero!

I am going to plot the phase spectrum of a zero-phase ricker wavelet. I calculate the fft of the wavelet and use the phase or ...
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25 views

How to perform Wiener deconvolution in Matlab

I have an output signal y which is an input signal x convolved * with an impulse response ...
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51 views

why upsampling contracts the spectrum?

I'm trying to understand why Matlab function upsample causes contraction in the spectrum, like the following figure shows. Also showed in mathwork online document. enter link description here ...
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28 views

Plotting Question: Intensity Plot for time series data set?

I'm wondering if it's possible to create functional intensity plots in matlab. Examples of what I'm looking for are below found in this paper: These figures were (guessing) probably made in R, ...
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1answer
31 views

Extending a waveform

Apologies if this makes no sense or seems rather simple, I'm a Matlab newbie. Basically, I've got a .wav audio waveform which I am resampling to various different frequencies and then trimming the ...
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1answer
41 views

downsampling an fft signal

I am currently working with a set of wavelet transforms that I came across in a paper. The paper suggests that I first apply the FFT on the source image and then perform the downsampling. So it says ...
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1answer
41 views

MATLAB MIRtoolbox - mirtempo function

I just want to know how functions like mirtempo(), which returns a mirscalar object to a direct format that MATLAB can ...
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17 views

problem in getting rank of matrix correctly

I have a equation to implement which result into the square matrix of orthogonal columns but non independent columns. The rank of this matrix does not seem to be correct. Can anyone help me? The ...
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32 views

Polygon Segmentation technique

I am working on Automated GUI components Segmentation problem. My Images are very simple as it has GUI components such as Buttons, text box and other polygons as you can see in the diagram (a). ...
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49 views

MATLAB implementation Spline Fitting

Let $s(t)$ be a signal that can be approximated by a uniform spline function of order $K$ (say $K=2$): $$s(t)\approx\sum_{n\in \mathbb{Z}}c_n\beta_+^{(K)}(t-n) $$ Suppose that we know the ...
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183 views

Matlab Neural Network toolbox

Is there any way to use as single input an image (256x256 pixels) and get output of single value using Matlab neural network toolbox
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34 views

generating a waveform in matlab for rohde and schwarz signal generator

We are doing a test which consists in sending a waveform from Matlab to the signal generator SMB100A and sending it through a cable to the r&s spectrum analyzer just to have a channel. We set the ...
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31 views

Hanning Window Formula - Matlab didnt work

Im trying to do the Hanning Window manually but didnt work, what Im doing wrong? t=[0:.1:10]; x=.5-.5*cos(2*pi*t/102); plot(x); Not sure why I cant obtain the ...
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29 views

0 accuracy on test data with 24 MFCCs

I have designed a classifier for "bols"(strokes) of the tabla, using the MFCC coefficients 2-13 (ignoring the first coefficient.) at the onsets. When I do a cross validation, I get approximately 46% ...
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23 views

What's $\omega _n$ difference between Matlab and Mathematica?

I want to plot this Butterworth filter's TransferFunction: ...
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1answer
46 views

Feature vector for MFCCs

I am working on a project, for which I am finding the onset times of an audio and then extracting the MFCC coefficients for all the times. Thus if I have n onset times, I would have n feature ...
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25 views

Normalized cut segmentation output correct or not?

I have implemented "normalized cut" segmentation. The change here is that, instead of giving an image as input, I have given an matrix of image. As my output looks odd to me. I need to know whether my ...
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1answer
52 views

What is the Roll-Off factor of a Root Raised Cosine Filter?

When designing a root raised cosine filter on Matlab, there is an option to set its "roll-off factor". What does this mean? I have been looking around for a while but I can't seem to find a clear ...