Community Profile # Matt J

Last seen: Today Active since 2009

Professional Interests: medical image processing, optimization algorithms

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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...

alrededor de 6 horas ago | 1

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

1 día 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...

1 día 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,:)) )

2 días 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.

2 días 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-...

2 días 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 ...

2 días 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

2 días 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 días 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 días 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 días 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 días 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 días 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 días 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...

3 días 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');

3 días 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...

3 días 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...

3 días 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...

3 días 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

4 días ago | 0

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How do a cell2mat conversion for a non-uniform cell to a matrix
cell2mat(DD(:))

4 días ago | 0

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

4 días ago | 0

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

4 días 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...

4 días ago | 0

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Plotting the solutions of an equation (rotated ellipsoid)
If you have the center, radii, and yaw-pitch-roll angles (in degrees) of the ellipsoid, you can plot a data-free ellipsoidalFit ...

4 días ago | 1

I dont understand why my table is displaying 1x1 sym and not a numerical value
You seem to be under the impression that vpa() converts a sym to a number. What you really want to do is use matlabFunction() to...

5 días ago | 0

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How can I create a set of N diagnal matrices range from diag(1, 1, ... , 1) to diag(-1, -1, ... , -1) for testing purposes?
Do you really need all Z{i} at the same time? [C{1:N}]=ndgrid([-1,1]); C=reshape( cat(N+1,C{:}) ,[],N); Z=zeros(N^2,2^N); ...

5 días ago | 1

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