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DFT
The DFT can be written as a matrix multiplication of a Nx1 vector, your signal, with a NxN matrix -- the DFT matrix. But that wi...

14 years ago | 0

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DFT
FFT() is just an efficient algorithm (actually a family of algorithms) for computing the DFT. The DFT is the mathmatical concept...

14 years ago | 0

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RUNNING A VIDEO
vision.VideoPlayer from the Computer Vision Toolbox implay - Image Processing Toolbox movie - base MATLAB

14 years ago | 0

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HOW TO ADD NOISE TO AN AVI FILE?
You can read the video frame by frame with a System object and use imnoise to add the noise. This assumes that you have the I...

14 years ago | 0

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quetsions about matlab pWelch implementation
You copied and pasted this code? x = randn(1024,1); Pxx = pwelch(x,512,0,512); xper = zeros(512,2); for k = 0:1 ...

14 years ago | 0

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extracted data from array
Why not just do: A = [0 5 3 0 0 1 0 2 4 1 1 0 4 0 1]; B = A(A==0|A==1); B = B(1:5);

14 years ago | 0

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Hanning Window
Hi Lisa, I don't whether I would say it's definitely "best". That is a hard thing to say, but the general rationale is that the ...

14 years ago | 0

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Modelling CIC Decimator
Hi Adeel, dsp.CICDecimator is a System object. That is more appropriate for streaming data and code generation if that is your u...

14 years ago | 0

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FFT - am i doing anything wrong
Hi Adam, the main problem is that your data does not have zero mean. This means that the zero frequency component (which isn'...

14 years ago | 2

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Magnitude of a filter
Hi Lisa, Filtering a signal usually implies convolving the signal with the impulse response of a linear time-invariant system. ...

14 years ago | 0

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quetsions about matlab pWelch implementation
Hi Neraj, Your question and code are quite long, so I'll just give you a simple example using two windows with no overlap on a r...

14 years ago | 0

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Subscripted assignment dimension mismatch.???
The problem is that the output of conv2(I2,G) should be the same size as I2 the way that you have written the code. In your ...

14 years ago | 0

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"if "function
Hi Vijay if isletter(input) disp('Please enter a number, not a letter'); end

14 years ago | 0

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what does this means.
Enter size(okpxls) after the line: okpxls = minr <= r & r <= maxr & ming <= g & g <= maxg & minb <= b & b <= maxb;...

14 years ago | 0

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how to find 4th value of vector in matrix
A=[2,3,6,8,7,5,4,2,7,8,9]; B = A(4)

14 years ago | 0

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what does this means.
repmat(okpxls,[1 1 3]) replicates (copies) an input into 3-D. x = randn(3,1); y = repmat(x,[1 1 3]); y has the same ro...

14 years ago | 0

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SPHIT algorithm
Hi Benitta, do you have the Wavelet Toolbox? If so, wcompress has an option to implement set partitioning in hierachical trees.

14 years ago | 0

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what does this do r = img1(:,:,1); % red channel g = img1(:,:,2); % green b = img1(:,:,3);
That is taking an RGB image, img1, and extracting the red, green, and blue parts and creating 3 2-D matrices: r,g, and b. An ...

14 years ago | 1

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help with a simple error
Are these files matrix1.txt, matrix2.txt, etc. located in a folder which is on the MATLAB path? Use addpath, or pathtool, to ...

14 years ago | 0

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wavelet transform
% assuming I was your input image X_newInPlace = zeros(size(I)); CA = X_newInP...

14 years ago | 0

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Histfit help
Hi, One way: % generate 1,000 N(10,2^2) RVs R = normrnd(10,2,1e3,1); % get an estimate of mu and sigma from the "data...

14 years ago | 1

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need help in this
Apparently sol is an MxN matrix. The code is simply assigning the 1st row, 1st column the value of P. And the second row, first ...

14 years ago | 0

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moransI correlation of matrix gives output value greater than one
Perhaps you would be better to contact the author: http://www.mathworks.com/matlabcentral/fileexchange/authors/26786 Since...

14 years ago | 0

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Sorting matrix
[~,indices] = sort(A(:,2)); A = A(indices,:);

14 years ago | 0

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Application of an LMS filter
But the adaptive filter presumes you have a desired signal. Otherwise, what is the filter adapting to? Are you sure in your appl...

14 years ago | 0

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awgn is missing?
I think it would be nice to have since that is your area. You can get the Communications System Toolbox as an add-on for you...

14 years ago | 0

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awgn is missing?
Hi, awgn() is part of the Communications System Toolbox. Do you have that product installed? Enter >>ver and see if...

14 years ago | 0

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Wavelet transform of samples collected irregularly in 2D space
Hi Asim, you can do the same thing with lifting in 2-D. The Wavelet Toolbox has a number of routines for lifting in both 1-D and...

14 years ago | 0

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filtfilt and filtfilthd give different results and behave differently under parallel for loop
filtfilthd is not a MathWorks' function. Beginning in R2011a, the MathWorks' function filtfilt accepts filters in biquad filter ...

14 years ago | 0

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signal processing in ecg
There are many ways with fdesign.bandpass and if you just remove the mean from the signal, I think you can just use fdesign.lowp...

14 years ago | 0