Matt J

Last seen: 1 day ago | Active since 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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Answered
I need to apply constrain using least square non negative function in Matlab
Use lsqlin instead.

1 day ago | 0

Answered
Slice of a 3D plot and projection of that function in a plane.
[x,y,yhalf]=deal(linspace(-2,2,100)); yhalf(y<0)=nan; Z = exp(-( x.^2 + y.^2')); figure, mesh(x,yhalf,Z,'FaceAlpha',1); ...

2 days ago | 0

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Answered
Why imregtform registration fails on similar images
Perhaps as follows, load Images g=@(z) entropyfilt(z); f=@(z) z.*(z>=1.5); im=f(g(im)); ref=f(g(ref)); ov=imref2d(size(i...

3 days ago | 0

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How to numerically evaluate this singular integral in integral2?
As demonstrated in the comment above, the integral is theoretically non-convergent unless c>=norm([10/a,10/b]). Here is a furthe...

3 days ago | 1

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Simply trying to find a value in the same row as my known value but in a different column.
Everything I have tried also gives me an answer of "0×1 empty double column vector," but without any value. You haven't shown...

4 days ago | 0

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Poor performance of linprog in practice
There are some papers in the computational literature that show that if you recast a DP problem as LP problem you can achieve si...

5 days ago | 0

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Answered
Can we specify an "outward" direction to normal obtained from pcfitplane approach?
I doubt you can, but it shouldn't matter. If the normal is pointing the wrong way, just post-process the fit by flipping its dir...

5 days ago | 0

Answered
Out of memory when solving large system of non-linear equations (fsolve, fminunc, ...)
I have more then 50000 variables. And ideally, I still want to scale up to number of variables. This means your Jacobian matrix...

7 days ago | 1

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Can I 'initialize' a handle object in such a way that isvalid(object) would return false?
One way: classdef ExampleClass < handle properties MyHandle end methods function...

8 days ago | 1

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Answered
How can I have the middle data set during the fitting process by lsqcurvefit?
Use the OutputFcn and/or the PlotFcn options, https://www.mathworks.com/help/optim/ug/lsqcurvefit.html#buuhcjo-options

10 days ago | 0

Answered
Why does the Stereo Camera Calibrator App provide different results on different MATLAB versions?
LIkely because the patterns are too similar across images, like the error message says. This would lead to ill-conditioning of t...

11 days ago | 0

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Error using nlinfit (Check FunVals)
For one thing, y = interp1(t,y(:,7),x1,'spline','extrap'); % cumulative reported cases For another, some sort of bounds or con...

11 days ago | 0

Answered
Why is the jacobian function so slow for calculating jacobian matrix with many variables?
Use matlabFunction to compute the jacobian from symbolic to numerical form, so that when it comes time to use it repeatedly, it ...

11 days ago | 0

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Different data processing depending on the spatial region of the points
Sure. Use inpolygon to detect in which region a given (x,y) point lies and compute the summation of mx variables accordingly.

12 days ago | 0

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Binning matrix data (negative and positive decimals): mean of each 100 rows and create a new matrix
Using sepblockfun() from, https://www.mathworks.com/matlabcentral/fileexchange/48089-separable-block-wise-operations B=sepblo...

12 days ago | 1

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Deep learning: predict and forward give very inconsistent result with batch normalisation
To get agreement, you need to allow the trained mean and variance to converge: numLayer = 9; numNeurons = 80; layers = featur...

13 days ago | 0

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Cannot figure out how to fit a complicated custom equation.
I recommend using fminspleas, downloadable from, https://www.mathworks.com/matlabcentral/fileexchange/10093-fminspleas for th...

15 days ago | 0

Answered
How does dlgradient handle two output layers?
Along the lines of what @Catalytic said, it is hard to envision how you are trying to use dlgradient without seeing that code. A...

15 days ago | 1

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Answered
how to extract the learned features from a dlnetwork
featureSet = forward(net,trainData,'Outputs',net.Layers(181).Name);

15 days ago | 0

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Is there a setting to move labels on a plot closer
You can use the axis label text object porperties to move them around, e.g., h=gca; h.XLabel.Position(end)=h.XLabel.Position(e...

16 days ago | 0

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Question

When did the syntax for linprog change
At one point, the input syntax for linprog was x=linprog(f,A,b,Aeq,beq,lb,ub,x0,options) but now (R2023b) I see that it has c...

17 days ago | 2 answers | 0

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answers

Submitted

Constrained minimum L1-norm solutions of linear equations
Finds least L1-norm solutions to linear equations C*x=d subject to linear and/or integer constraints.

17 days ago | 7 downloads |

Answered
The issue of optimization (minimization) of the average relative error between experimental and calculated data
If you download minL1lin from https://www.mathworks.com/matlabcentral/fileexchange/52795-constrained-minimum-l1-norm-solutions-...

17 days ago | 0

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Answered
How can I efficiently save and access large arrays generated in nested loops?
I used the following given method to save the data, and it produced an 11 GB file, which seems very large. The memory consumpti...

17 days ago | 0

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Answered
Why ILP Solver Switching to Branch-and-Bound?
Assuming you are using intlinprog, it will always uses the branch-and-bound algorithm at some stage of the processing (not sure...

18 days ago | 0

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Answered
How to average across tables in a cell
AvgTb=Tb{1}; AvgTb{1}{:,:}=(Tb{1}{:,:}+Tb{2}{:,:}+Tb{3}{:,:})/3;

19 days ago | 0

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Answered
Detecting circles in an image to measure inner and outer diameter
Because of the angle of the camera, circular shapes like the ones you are looking for are imaged as ellipses. Since imfindcircle...

19 days ago | 0

Answered
Find strings within other strings then pull data from that point
fileContent = fileread('P0300.txt'); prefix="01 3E"; e=" "+digitsPattern(2); pattern = prefix+e+e+e; matches = extractAf...

19 days ago | 0

Submitted

Array Concatenation with Implicit Expansion
Versions of cat(), horzcat(), and vertcat() that support implicit expansion

22 days ago | 4 downloads |

Answered
Finding the closest coordinate from a surface plot based on a X, Y location
F=griddedInterpolant({Slab_strike.x,Slab_strike.y},Slab_strike.z,'linear','nearest'); Strike = F(lon_GMM,lat_GMM);

22 days ago | 0