Matt J

Last seen: Today | Con actividad desde 2009

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Professional Interests: medical image processing, optimization algorithms PLEASE NOTE: I do not read email sent through my author page. Please post questions about FEX submissions in their respective Comments section.

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polyshape not closing a circle
%gui = uifigure; %g = geoglobe(gui,"Basemap","satellite", 'NextPlot','add'); wgs84 = wgs84Ellipsoid("nm"); lat0 = 42.3601; l...

alrededor de 5 horas hace | 0

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Why does the Code Analyzer flag this as an error?
Mathworks Support has classified it as a bug.

alrededor de 11 horas hace | 1

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How do you change the output dimension of a NN layer?
Should I flatten the inputs and then concatenate them similar to this example? Probably. See if the attached network does what...

1 día hace | 0

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Display a small matrix as a gray scale image
T2 =[ 0.4706 0.9804 0.8392 0.3216 0.9804 0.8392 0.3216 0.4706 0.8392 0.3216 0.4706 0.9...

1 día hace | 0

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How to freeze specific neuron weights in a feedforward network during training process?
I don't think you can do it without the Deep Learning Toolbox. If you have the Deep Learning Toolbox, you can define a custom la...

2 días hace | 0

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Please help with this multiplication problem
You can multiply directly. Example: [m,n,r]=deal(3,4,2); A=rand(m,1,r); B=rand(1,n,r); C=A.*B; whos A B C

2 días hace | 0

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sub2ind() errors out with NaN inputs - handled differently since R2024a
You can get the old behavior back if you need it, Sub2Ind([ 3 5 7], [ 3 3], [2 2], [1 nan]) function out=Sub2Ind(sz,vararg...

2 días hace | 0

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Non-linear constraints format for GA using solve function
I would formulate it as, N=numel(Pos_Input_mtx); problem.Constraints.c1=abs(Pos_Input_mtx(:)-Pos_Input_mtx(:)') >= (1-eye(N)...

2 días hace | 0

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Summing function handles of multiple variables across one of the variables
Nesting function handles n-fold is going to be very inefficient, and is usually not a good idea. Usually, it is best to vectoriz...

3 días hace | 0

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Error using trainNetwork Invalid training data. For classification tasks, responses must be a vector of categorical responses. For regression tasks, responses must be a vector
Instead of using Matlab's dicePixelClassificationLayer, you can try the following custom output layer: classdef GeneralizedDice...

5 días hace | 0

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Ifft2 results do not match that of irfft2 in Pyhton
I'm not a Python user, but if rfft2 only gives you positive x-frequencies, I would imagine it also only gives you positive y-fre...

6 días hace | 0

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Three dots at the end of a line of code
Why does one of my lines of code have three dots enclosed in a box? What does it mean? Clicking on it does nothing.

7 días hace | 1 respuesta | 0

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Looking for linear system Ax=0 precision improvements
s=max(abs(A),[],1); x = null(A./s)./(s')

7 días hace | 0

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Finding x and y values of minimum z in 2-variable function.
The continuous minimum can't be at (5,2) as you claim. Direct evaluation shows that the value of z at (5.5,10) is lower. loopi...

8 días hace | 0

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Using fft and ifft with less frequencies than input points
What I would want to do, is to insert an N, f.e. N=100, but get an array 10001x1. %Grid Nx = 100; L = 10; dx = L/(Nx-1); ...

8 días hace | 0

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Why does the Code Analyzer flag this as an error?
Why does the Code Analyzer flag this code as an error? It runs fine: try error("It's bad") catch ME warning('Error...

8 días hace | 2 respuestas | 0

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How to fastly calculate this real number matrix manipulation?
e=(1:A)'; I=reshape(e,1,1,[]) == repmat( e,1,B); Xp=permute(X,[3,2,1]); D=X./(X-Xp); D(I)=1; M = ipermute( prod(D,1) ,[...

10 días hace | 0

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How to solve the error generated while defining custom FFT layer?
Your predict() method is written to expect that the input X will be a cell array. It's not clear why you expect this, but you sh...

10 días hace | 0

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How do I edit a loop to be able to store the variables and outputs used in each loop in a way which can be graphed?
D = 0.3 k = 0.0002 Rvalues = 10^4:10^5:10^8; nR=numel(Rvalues); X=nan(1,nR); for i=1:nR R=Rvalues(i); ...

10 días hace | 0

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reshape 4-dimension array
Download this File Exchange package, https://www.mathworks.com/matlabcentral/fileexchange/115340-block-transposition-permutatio...

11 días hace | 0

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Speed up this bottleneck line of code
If you can construct c in transposed form, there are some savings to be had, n = 10000; m = 5000; k = 20; a = rand(n,m);...

12 días hace | 0

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nonlinear spline fit with unknown upper bound of interpolation domain
The upper bound is way larger than the fitted parameters at x < 6, causing an extremly large curvature at x > 6 which makes the ...

16 días hace | 0

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Differentiating in one direction using FFT2
fft2(u) is equivalent to fft( fft(u,[],1) ,[],2), if that helps at all. Truthfully, it doesn't appear that you need to use fft2...

16 días hace | 0

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need to vectorize efficiently calculating only certain values in the matrix multiplication A * B, using a logical array L the size of A * B
Is v much smaller than m or n? If so, one approach might be with an outer product decomposition: L=sparse(L); %if L was not pre...

17 días hace | 1

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shared colorbar for specific plots in tiledlayout
Using nestedLayouts from the File Exchange, https://www.mathworks.com/matlabcentral/fileexchange/161736-grids-of-tiled-chart-la...

18 días hace | 0

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MATLAB Optional Function Arguments
Using the arguments block is more robust, but I'm unable to find a way to make multiple inputs independently optional. The way ...

18 días hace | 2

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Set number of rows in output variable using indexing within for loop, add variable to new table
I would like to put the two calculated variable columns directly after the variable column in the original table. And you want ...

19 días hace | 0

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What happens if the termination condition is satisfied before the constraint in matlab's fmincon?
The only time fmincon will stop without satisfying the constraints (within ConstraintTolerance) is if the MaxItertions or MaxFun...

19 días hace | 0

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How to remove columns in very large matrices.
Use a sparse matrix, if applicable. matrix=sprand(1750000 , 2000, 1000/1750000); whos matrix tic; matrix(:,1:3:end)=[]; ...

19 días hace | 0

Pregunta

Suppress uitable cell borders
In Excel, there are buttons to select particular spreadsheet cell borders and hide them. Is there an analogous way to suppress t...

20 días hace | 1 respuesta | 0

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