Tagged Questions

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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0answers
6 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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0answers
16 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 ...
0
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0answers
11 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 ...
1
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0answers
26 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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0answers
26 views

MATLAB implementation Spline Fitting

Check the attached problem please. I am a beginner in spline fitting and have a few questions: 1) How to find the coefficients $c[n]$. Is it by DTFT? 2) I understand how to find the derivative but ...
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1answer
40 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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0answers
28 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 ...
-1
votes
1answer
26 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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0answers
25 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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0answers
22 views

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

I want to plot this Butterworth filter's TransferFunction: ...
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1answer
29 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 ...
2
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0answers
21 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
25 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
19 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 ...
1
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1answer
59 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 ...
0
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1answer
32 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 ...
0
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1answer
56 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
62 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
12 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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0answers
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
27 views

Enhancement Of Ecg Signal [closed]

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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1answer
19 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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0answers
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 ...
0
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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 ...
0
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0answers
18 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
51 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
44 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
11 views

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

Matlab code for implementation of accelerometer data and kalman filter required.ASAP Any help is welcome.
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1answer
100 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: ...
0
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0answers
44 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 ...
0
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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 ...
1
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2answers
58 views

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

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?
0
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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
24 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
16 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
63 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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0answers
31 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 ...
-1
votes
1answer
39 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. ...
0
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1answer
31 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 ...
0
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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 ...
0
votes
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
40 views

cross power spectral density explanation in matlab

let us consider following code ...
-2
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1answer
48 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] ...
-1
votes
2answers
31 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 ...
0
votes
1answer
46 views

Learning fundamentals of OFDM (Theory & Simulation) [closed]

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 ...
1
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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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0answers
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 ...
0
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0answers
20 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 ...
0
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0answers
58 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 ...