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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20 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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13 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
15 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 ...
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1answer
16 views

PSNR of two images of different size in matlab

I performed bicubic interpolation on a 256*256 image(img) dest = interp2(img,'bicubic') and i got a 511 * 511 image.I want to compute PSNR of a 512 * 512 ...
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1answer
46 views

Find a sinusoidal fit from data with fft

I have a vector with raw data (120 samples). From the frequency spectrum I can tell there is one dominant frequency component. Now I am supposed to use the fft data (magnitude and phase) to find a ...
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1answer
31 views

Developing a classifier for a periodic music

I am trying to develop a classifier for Indian Taals, for which I would be focusing only on the Tabla. Now once a extract a period of the Tala(a repetitive pattern), I want to develop some feature ...
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1answer
53 views

Plotting DFT in dB

I'm having a little trouble plotting the DFT of a signal in dB. I can get the picture up nicely when using the magnitude but when I try converting the magnitude to decibels it all goes south. I've ...
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3answers
60 views

Choosing the best measure for machine learning on a Spectrogram

I am working on an application to classify Talas(a piece of music with onsets). For that, I have the spectrogram of a Tala, which I want to compare with the test Tala, or compare 2 Talas. For this I ...
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0answers
8 views

Dirty Paper Coding Precoding MU-MIMO BC Channel

I'm on my final paper work and I have a lot question to ask since I'm a newbie. so here it is, I'm working on Precoding Dirty paper coding MU-MIMO in broadcast channel with selective frequency fading. ...
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24 views

How to remove modulation frequency and its harmonics

I have amplitude modulated sound file signal and after demodulation using FFT I got fundamental frequency and its harmonics and of course noise. How to remove that fundamental modulation frequency ...
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0answers
25 views

Enhancement Of Ecg Signal [on hold]

Load, display and manipulating of ECG signals Design notch filters both in FIR and IIR for 50 Hz and 100 Hz respectively. Design a band pass filter to eliminate muscle noise. Plot the spectrum of ...
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0answers
11 views

Anyone know about 2D S transform [closed]

Please provide how to convert 4D to 2D S transform. Implementing 2D stransform
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1answer
15 views

A question about image compression with SVD - MATLAB

I have to compress an image by using svd. I did a few things but all of them produced gray image. However, Output must be rgb. How can i compress an image without changing its original format?
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17 views

uniformly distributed random signal

i need to generate an uniformly distributed random signal.... i was seeing in the internet that "The uniform distribution (also called the rectangular distribution) " and " A uniform distribution has ...
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0answers
17 views

computing peak to peak ratio in matlab

i need to compute a signal's peak to peak ratio..... i have a doubt... do we calculate a signal's Peak to peak ratio in time or freq domain.... and ok say for a sine wave i can understand how to ...
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0answers
16 views

generation of frequency with magnitude 1

hi i need to generate F=[F0,F1,........Fn-1] wer n=16 such that lFnl=1..... so i understand i need 16 freq samples whose magnitude sums upto 1..... now i need to generate it in matlab...... can anyone ...
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2answers
49 views

ecg signal analysis

I'm a newbie and I have a few questions regarding ecg signal. Here is my plot of raw ecg signal with a sampling frequency 200Hz in Matlab. Does it look good to you? Why is it flipped?
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1answer
41 views

Comparing the FFT to numerical integration in Matlab

The result of calculating the fourier transform using numerical integration is: the result of using Matlab's FFT is: So where did I go wrong here? I know the FT of a Gaussian should be ...
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0answers
9 views

kalman filter for accelerometer of mobile device.can it measure exact displacement? [on hold]

Matlab code for implementation of accelerometer data and kalman filter required.ASAP Any help is welcome.
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1answer
93 views

Cooley-Tukey Implementation of FFT in Matlab

For my course I need to implement a 30 point Cooley-Tukey DFT by transforming it into a 5x6 matrix. I have tried to implement using the following Matlab code: ...
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43 views

DFE for QPSK in matlab

I need to do a DFE for QPSK simulation in matlab. The system, consist in QPSK signal transmitted with power = 1. Then pulse shapping with a square raised-cosine filter. Add AWGN and a filter receptor ...
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0answers
20 views

wavelet analysis for signal when frequencies are known in advance

i would like to ask one question, generally wavelet analysis helps us to identify which frequencies at which time interval was occurred, but the point is that both frequencies and time intervals ...
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2answers
55 views

how to detect corner in a digital image using MATLAB? [on hold]

I am designing an algorithm for image processing. I am using MATLAB for the processing of the images(video). How I can detect the position of the corners in the image?
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1answer
25 views

What is the best Algorithm to estimate the frequency for Almost-Periodic Data or complex periodic data?

I’ve got what it looks like a periodic signal but the periods seem not equally repeated, I want to estimate the PSD, particularly I need to obtain the dominant frequency of this data. I’ve estimated ...
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0answers
25 views

Is speech stationary ? How do I test it in matlab?

I'm taking a "Random Signals" class in school and I've got an simple assignment about speech in matlab. I have been asked to record two files: A single word or sentence. A couple of syllables each ...
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0answers
10 views

License manager error-4 [on hold]

How to resolve this error? Whenever i am using 'syms' it shows this error:- "Error using sym License checkout failed. License Manager Error -4 Maximum number of users for Symbolic_Toolbox reached. ...
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0answers
22 views

How to smooth out a noisy signal?

I've been waiting for an answer to my question here therfore I decided to ask the question in a different way. Could anyone please help me to smooth out the signal below!!. I've no experience of ...
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0answers
15 views

Time invariance and time variance [duplicate]

How can I write a MATLAB program that takes the given system described in terms input x(t) and output y(t) relations is input and finds out whether it is time-invariant or not?
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1answer
62 views

Discrete algorithm for low pass filter

I am working on a position controller for a marine vessel. I have an measurement signal containing the y-position of the vessel that consists of both low frequency (<.1 rad/s) and high frequency ...
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28 views

Getting error in PSNR calculation using Matlab

I want to find out PSNR and SNR values of two images A and B of same dimension in Matlab.I used the following code [peaksnr, snr] = psnr(A,B) and getting an ...
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1answer
36 views

Get a power spectral density from real random data

I am using real data of wind, which is a random one to get the power spectral density of these values. How can I do to get this PSD in matlab, and Can I get an analytical expression for this psd. ...
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1answer
30 views

Image getting completely white on downsampling

I performed an image downsampling with averaging operation(The image is divided into 2 by 2 blocks,then it is downsampled by 4 times.New pixel values od downsampled image is replaced with the mean of ...
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0answers
11 views

Meaning of events in EEGlab

I'm reletively new to the EEG signal processing domain and EEGlab and I'm trying to figure out the meaning and the following terms used in EEGlab and in general context in EEG.It will be helpful if ...
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1answer
15 views

Different results for seperable filtering v/s direct filtering on 2-D image in MATLAB

I compared the difference between seperable and direct filtering for MATLAB's cameraman image. The difference is huge. I would like to understand the reason for this. Code below. ...
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1answer
36 views

cross power spectral density explanation in matlab

let us consider following code ...
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1answer
47 views

fft of a complex signal

I am new to dsp and just have a vague understanding of fft process. i know fft is used to convert time to freq domain.... i need to generate a sequence of frequencies such that F=[F1,F2,.....Fn-1] ...
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2answers
28 views

Implementing image chroma keying with FIR filter in MATLAB

Is there any way I can apply the concept of FIR filters in chroma key composition, where I will remove a green background to focus on a subject and replace a different image on the removed part, sort ...
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1answer
45 views

Learning fundamentals of OFDM (Theory & Simulation) [on hold]

Will you please suggest me some basic fundamental reference to learn OFDM techniques. I am looking for underneath theory with some basic mathematical explanations of CP, Subcarrier, FFT Size, Pilot ...
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1answer
34 views

Characterising a system from its input and output

I have 2 data sets sampled at regular intervals which represent the input and the output of a system. A quick analysis of the plots shows the following: There is a proportional factor between the ...
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13 views

.ptw Video conversion

On Video recording with IR camera, a file in .ptw is obtained. I want to analyze the file using standard software, like MATLAB. However, video processing in MATLAB requires the file to be converted to ...
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18 views

How to add bandpass filter to recorded sound in matlab

I have a sound that is being recorded but I am trying to apply bandpass filtering to the sound so that it filters out anything above and below a selected frequency range. I have tried the tool in ...
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49 views

Radon Transform Implementation In Matlab

I know MATLAB has a built in Radon function, but I am working on implementing the radon transform in order to perform filtered back projection. As I started, my idea was multiple nested for loops for ...
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35 views

Removal of skull stripe from MR image

How to remove the skull stripe from an MR image and to get the csf part from the image clearly? ...
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0answers
28 views

How to display images with log axes? [on hold]

I'm trying to plot few points on existing log-log graph, for comparison. I've saved the existing graph as .png image then I plotted the points on the image!. The difficulty I'm having is how to ...
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0answers
13 views

Inverse Distance Weighting Filter

I am trying to use “inverse distance weighting” to improve on some 2D map (called B1-map in MRI field). I am generating this map on voxelwise basis. My algorithm returns the value right most of the ...
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0answers
61 views

What is the best method to estimate the frequency(PSD) for noise signal

I’ve been trying to estimate the frequency of a signal I obtained at 1000Hz sampling frequency. The dominant frequency is expected to be not more than 4 or 5 Hz. I’ve estimated the PSD using ...
2
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1answer
86 views

Bicubic Interpolation

I'm trying to do bicubic interpolation on an 8*8 matrix(image) shown below. ...
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0answers
27 views

Linear time-invariant time response kernel, MATLAB vs Octave

I am trying to get some MATLAB scripts to run in Octave, but have a problem with the following line of code: x = ltitr( a, b, u, x0 ) ; which throws an error in ...
0
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1answer
88 views

Solution to Cross-correlation problem of 2 audio signals

There are 2 audio signals, X & Y. X is of 15 second duration. The duration of Y is not given. Y is a part of signal X (ie a small part of audio X is extracted & made into audio Y) I have to ...
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3answers
66 views

Appying a Filter Several Times on Data

I have data from an experiment and apply a lowpass filter (digital Butterworth filter, in Matlab). My question ist what happens if I apply the same filter e. g. 2 times on the data? What is ...