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Double sum of a series
Why do you want to implement you own convolution when Matlab already has a very fast function for that? For loops are slow. ...

presque 7 ans il y a | 0

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Understanding MATLAB file access
Hello, I'm working on a script where I have to read hundreds of images and do some calculations on them. I'm using a simple f...

presque 7 ans il y a | 1 réponse | 0

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Question

What is drawnow doing?
Hello everyone. I'm working on a code where I need to alternate the display of two complex plots in a very short time. The ti...

environ 7 ans il y a | 1 réponse | 0

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Question

Optimization of variable-length array
Hello, I'm trying to optimize a code where I have an array with unknown size and I'm not sure about two solutions that I have...

plus de 7 ans il y a | 1 réponse | 1

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A répondu
Discrepancy between xcorr2 and fft2
I figured it out by myself, and I uploaded a script on the file exchange to get a numerically equivalent function of xcorr2 whic...

plus de 7 ans il y a | 0

Question

Discrepancy between xcorr2 and fft2
Hello! I want to implement an fft cross-correlation in my algorithm in order to replace the much slower xcorr2. In theory, d...

plus de 7 ans il y a | 1 réponse | 0

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Question

Does keyboard slows down the code?
Hello. I was doing some tests to speed up my code, and I realized that having a keyboard in the code slows it down, even if t...

presque 8 ans il y a | 1 réponse | 0

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Question

Parfor loop and variable length output
Hello everyone, I would like to speed-up a code using a parfor loop but my function is not straightforwardly suitable for it....

presque 8 ans il y a | 1 réponse | 0

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Question

Boolean matrix in mex file
Hello everyone, I'm trying to read a logical matrix in a mex file with matlab. The way I usally do for reading matrices in ma...

presque 8 ans il y a | 1 réponse | 0

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Question

Automatically generate functions from snippet of a script
Hello, When I write a code in matlab, I usually start writing a script. When the script gets bigger, I transform it into a fu...

presque 8 ans il y a | 1 réponse | 1

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A répondu
Does it possible to use a function with persistent variables several times?
If you want to clear the persistent variable you need to do it explicitly: clear example

presque 8 ans il y a | 0

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Mex results different from linux to windows!
I answer myself. The problem was related to the function abs. In gcc, math.h has a C version of abs that works on integers, so g...

presque 8 ans il y a | 0

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Mex results different from linux to windows!
Hello everyone. I have a mex routine written in C++ that I use on a Windows computer compiled through Visual Studio. Now I ne...

presque 8 ans il y a | 1 réponse | 0

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A répondu
may i directly convert video to text document using matlab ?
You can use matlab OCR function: <http://uk.mathworks.com/help/vision/examples/recognize-text-using-optical-character-recogni...

presque 8 ans il y a | 0

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how to display a query image and database side-side ? i have few lines but i am not able to proceed ahead with them as they are incomplete .
Maybe you want to use subplot: figure subplot(1,2,1) imshow(im1) subplot(1,2,2) imshow(im2)

presque 8 ans il y a | 0

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How to stop printing anything to command window?
The best solution would be using disp inside an if statement. A really bad soulution (still working) would be replacing the fun...

environ 8 ans il y a | 0

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script running for 13 hours. should I be worried?
You can use a task manager to check if matlab is still using the CPU. If not, it probably got stuck.

environ 8 ans il y a | 0

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Find the distance between object and camera
Calculating the distance between an object and a camera in not an easy task. In theory, you would need two different cameras bec...

environ 8 ans il y a | 0

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Why are vectors horizontally and matrices vertically indexed?
Matlab variables are always indexed vertically. What you are talking about is a plot behaviour: plot(X,Y) plots vector Y v...

environ 8 ans il y a | 0

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estimate time needed for a code to finish
This is my favourite solution: tic for i = 1:1e9 if toc > 10 fprintf('Iteration %d/%d\n',i,1e9) ...

environ 8 ans il y a | 2

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A répondu
Calculating statistical PDF and percentiles over matrices
You can replace x with x(:) in prctile. The whole matrix will be squeezed in a single vector what will be evaluated just once.

environ 8 ans il y a | 0

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The definition of variables
You can create integer random vectors with randi(), convert it to binary with de2bi(), and convert input binary to decimal with ...

environ 8 ans il y a | 0

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A répondu
HELP with Undefined variable, size of the indicated variable changes with each loop iteration.
The variable files is a cell array, and you are trying to refer it as a matrix. You should use files{i} instead of files(i,1) wh...

environ 8 ans il y a | 0

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how can i make my scattered 3 dimensional data points as a 3d surface?
tri = delaunay(k(:,1),k(:,2)); trisurf(tri,k(:,1),k(:,2),k(:,3))

environ 8 ans il y a | 0

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environ 8 ans il y a | 0

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How to find the variance of an image in a special windows? variance(in 3*3 windows)
You can use the function conv2: A = imread('foo.bmp'); small_window = ones(3)/9; A_sq = conv2(A.^2,small_window,'s...

environ 8 ans il y a | 0

A répondu
Problem in Plot diagrams
I cannot see your attachment, but you can use any char you wish for your plot, just using text instead of plot: x = linspac...

environ 8 ans il y a | 0

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How to use threshold in this problem?
Supposed your image varies from o to 1, you could use a threshold in this way: THR = 0.5 above = image>=THR; imag...

environ 8 ans il y a | 0

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A répondu
Distance from 3d point to an ellipse
A simple and straightforward solution could be discretizing the points of the ellipse, evaluating the distance from all the poin...

environ 8 ans il y a | 0

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How to convert an acceleration time graph, into a velocity time graph
You can integrate the acceleration vector with cumsum or cumtrapz to get the velocity, and again to get the space.

environ 8 ans il y a | 0

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