Community Profile # Matt J

Last seen: Today Active since 2009

Professional Interests: medical image processing, optimization algorithms

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How to plot the value of a matrix?
plot(yourMatrix)

3 hours ago | 0

what changes should i make in final optimised value with opt time vector
Use prob2struct s=prob2struct(prob); s.f0 The value of s.f0 will be the discrepancy between a problem-based linear optimizati...

3 hours ago | 0

fminunc giving correct optimized values for anonymously defined function, BUT wrong value for .m function
At same initial values in two cases (anonymous function and .m function) the objective function gives same values which means th...

6 hours ago | 0

How do I create a matrix that has as values ​​the averages of variables found in loops?
If that's all you want to do, you shouldn't be saving the coordinates of the ROIs. You should just create a binary mask BW of ea...

1 day ago | 1

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How to assign a specific values to the nearest X,Y point

2 days ago | 0

I am trying to compute the zero of a function using fzero, but the system always says my function must be finite and real. How can I solve that? Thank you!
Clearly, your function is non-finite at x=0. There is a factor of x^2 in its denominator. Regardless, fzero() is the wrong too...

3 days ago | 0

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Loop in a cell array that consist of matrices in each cell
Easier: results=cat(3,results{:}); max_column = squeeze( max(results(2:end,12,:)) )

3 days ago | 0

Loop in a cell array that consist of matrices in each cell
You have a variable called "max" previously defined in your workspace.

3 days ago | 0

I would like a function to remove the duplicate values, but one that removes the duplicate value as well.
USing the functions in https://www.mathworks.com/matlabcentral/fileexchange/78008-tools-for-processing-consecutive-repetitions-...

3 days ago | 0

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fminunc crashes matlab if large number of input variables used
Well, the practice you have of cumulatively nesting anonymous functions inside one another is asking for trouble. You should at ...

3 days ago | 1

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How to apply logical matrix to the matrix with array operation?
Matrix = [ 3 4; 5 6]; Logical= [ 1 1 ; 0 0]; R=Logical.*Matrix

3 days ago | 0

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How to substitute one value in vector by vector?
x=[-1 1 -1 1]; X=kron(-x,[1,2,3]); X=X+4*(X<0)

3 days ago | 0

How to substitute one value in vector by vector?
x=[-1 1 -1 1]; x=strrep(10*x,10,[3,2,1]); x=strrep(x,-10,[1,2,3])

3 days ago | 0

why the caculation results is different for parfor-loop and for-loop?
Probably because, with a parpool active, the matrix multiplication code cannot multithread the operation in precisely the same w...

3 days ago | 0

Is there any exmaple on how to apply fmincon function to a state space optimisation problem?
These should be applicable, https://www.mathworks.com/help/optim/ug/fit-ode-problem-based-least-squares.html https://www.mathw...

3 days ago | 0

How to substitute one value in vector by vector?
x=[-1 1 -1 1]; i=(x+3)/2; V=[1 2 3;3 2 1].'; X=reshape( V(:,i) ,1,[])

3 days ago | 0

How to substitute one value in vector by vector?
x=[-1 1 -1 1]; idx=(x==1); X=nan(3,numel(x)); X(1,idx)=3; X(2,idx)=2; X(3,idx)=1; X(:,~idx)=4-X(:,idx); X=X(:)....

3 days ago | 0

Calculation of Hessian matrix in gamultiobj hybrid function
If you mean that you can't compute the Hessian yourself and wish to do so using finite difference approximations then https://w...

4 days ago | 0

Finding the average of the neighbors of each pixel in an image
mean4=conv2(image,[0 1 0; 1 1 1; 0 1 0]/5,'same'); mean8=conv2(image,ones(3)/9,'same');

4 days ago | 1

Issue while fitting semi-circle on a set of points
See incircle() in https://www.mathworks.com/matlabcentral/fileexchange/34767-a-suite-of-minimal-bounding-objects?s_tid=srchtitl...

4 days ago | 0

Issue while fitting semi-circle on a set of points
I recommend circularFit from https://www.mathworks.com/matlabcentral/fileexchange/87584-object-oriented-tools-for-fitting-conic...

4 days ago | 0

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Using a loop to impose specific values
For example, x=linspace(-1,1,1000); plot(x,twoparts(x)) function y=twoparts(x) y=abs(x); region=x>0; y(region)=x...

4 days ago | 0

combining results into a single matrix
One way. h = [1 2 3 4 5]; n=numel(h); m=n-2; First_Matrix=toeplitz([1,zeros(1,m-1)] ,[1 1 1 zeros(1,n-3)]).*h

5 days ago | 0

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how to fix subplot images
subplot(4,5,ii-15)

5 days ago | 0

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How to make a variable negative if another variable is negative?
X1=X.*sign(Y);

5 days ago | 0

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Intersection of two lines
You need a least squares solution, since lines in 3D do not generally intersect. Assuming your point data are in column-vector f...

5 days ago | 0

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