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# Matt J

Last seen: Today Active since 2009

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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Vectorized solution to replace for loops in nested combinations
Well, you can at least reduce it to 2 loops: T=50; nb2 = zeros( T, 1 ); tic for t = 1:T t1=0:t; ...

ungefär 7 timmar ago | 0

Optimization Curve Fitting: Curves are not converging
One immediate problem that I see is that in sseval, the optimization variables x(i) aren't used at all in the calculation of sse...

ungefär 11 timmar ago | 0

What does this script mean?
It means minimize fun(x) over x for each set of fixed parameters t,c,p,VN. The initial guess for the minimization is g. The mini...

ungefär 11 timmar ago | 0

How to use the Sum function in this instance
Assuming all your variables (x,z,Ar, etc...) are scalars, then, fi=5:85; q1=0.5*cosd(fi).^2; q2=q1+z^2; q3=sqrt(x^2+q2); ...

ungefär 19 timmar ago | 0

Question

Preference settings for command line table display
In R2021b, tables display at the command line as below on the left, whereas in R2022a, it displays as on the right, in a collaps...

en dag ago | 1 answer | 0

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Why am I receive Fmincon error ?
x0 = ones(3,21);

en dag ago | 1

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How to select fields of a struct that contains certain string?
load table for i=1:numel(trial_table) s=trial_table(i).trial; [~,loc]=ismember({'1','2'},{s.message}); result(i)...

en dag ago | 0

using lsqcurvefit for fitting the convoluted function to the data set
As a first pass, you should probably approximate the Fermi function by an ideal step function, so that the "convolved Gaussian" ...

2 dagar ago | 1

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Unable to solve nonlinear equation using fsolve as the message shows No solution found
You haven't shown how the optimization was executed. fsolve appears to work fine below: opt = optimoptions('fsolve', 'FunctionT...

3 dagar ago | 1

How can we find the intersection between two planes in higher dimensions (4d space and above)?
In general, intersections of two hyperplanes would be expressed algebraically by a 2xN set of linear equations Aeq*x=beq. A geom...

3 dagar ago | 1

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How to find the orientation of the line of the intersection between two planes?
P1 =[177668442.453315 ,-102576923.076923, 0]; P2 =[ -102576923.076923 ,177668442.453315 ,-102576923.076923]; P3= [0, -1025769...

4 dagar ago | 1

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Defining and calling functions in matlab
function fx = wbl(X)

4 dagar ago | 0

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How do I save for loop plots to a figure directory?
One possibility: saveas(gcf, fullfile(OutputFigures, "FIG"+i) );

4 dagar ago | 0

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Why do I get different outputs for fsolve when I use different initial point?
Why do I get different outputs for fsolve when I use different initial point? Because you have local solutions. You need to cho...

4 dagar ago | 0

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Fminsearch for fitting models (unconstrained nonlinear minimization of rmse)
rmse= sqrt(sum((ydata-(c1./(1+exp(-a1-b1.*xdata))+c2./(1+exp(-a2-b2.*xdata))+d).^2))./numel(xdata));

4 dagar ago | 1

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How can I efficiently use an array of patterns to create figure titles?
One possibility: regNames = ["Anterior HPC" "Posterior HPC" "Amygdala" "Enthorinal Cortex" "Pararhinal cortex"]; pats = "u" + ...

6 dagar ago | 1

2D matrix transformation (Brown-Conrady distortion model) fitting
You can use lsqcurvefit if you have the Optimization Toolbox.

6 dagar ago | 0

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As you can see from the plot, the root lies quite close to solution, so fzero succeeded. If this violates your expectations, it ...

6 dagar ago | 0

Question

Why is it forbidden to call a superclass method from a subclass function of a different a name?
I tried the thing in the screenshot below, i.e, to call the super-class method getThis() within the sub-class method someFunc()....

6 dagar ago | 0 answers | 0

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How to find the line of intersection between the following two planes and plot the intersected line on the same two planes?
You can get the line of intersection in Dual Plucker Matrix form as follows: A=null([[P11;P21;P31],ones(3,1)]); %plane 1 B=...

7 dagar ago | 0

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Length of lower bounds is < length(x); filling in missing lower bounds with -Inf. Problem is unbounded
A=readtable('4times6249datacsv'); A=table2array(A); f=sum(A,2); Aeq =ones(1,4); beq = 1; lb = zeros(4,1) ; a = linpro...

7 dagar ago | 0

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Maximization problem in MATLAB Optimisation Toolbox
Will it work same here? Yes. Example: fun=@(x) -x^2; %maximize this xmax=fmincon( @(x) -fun(x) , 1) It worked!! But anoth...

7 dagar ago | 1

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Given a quadrilateral image, not necessarily a rectangle, how to find its top left point's x-y coordinate
You can use pgonCorners from https://www.mathworks.com/matlabcentral/fileexchange/74181-find-vertices-in-image-of-convex-polygo...

7 dagar ago | 0

How to use Matlab Functions with Vector of Structures
m = min([struct.field1])

7 dagar ago | 0

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Defining objective functions appropriately
It depends what environment you are formulating the problem in. fmincon and fminunc will only minimize functions, so you cannot ...

7 dagar ago | 0

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Matrices multiplication (a*b)
By using a loop, and the definition,

7 dagar ago | 0

Question

Isn't it dangerous to allow Comma-Separated-List functionality in indexed assignments?
I have a function below called renamefields() which, as the name suggests, renames a desired subset of struct array fields as de...

7 dagar ago | 1 answer | 0

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How to get comlex root of an equation using fminbnd?
fminbnd is for minimzing over a 1D interval. It's not clear to me how you are defining 1D interval bounds for a number that does...

8 dagar ago | 0

Issues in the constraint functions of the Optimization Problem solving
function [c,ceq]= area(x0) M=5; % x0=[5,8]; M2=m(M,x0(1)); M3=m(M2,x0(2)); M4=m(M3,(x0(1)+x0(2))); beta1=b(M,(x0(1)))...

8 dagar ago | 0

collapsing rows of a cell array into a single cell
Data2=num2cell(Data,1); However, I wonder why you would want to do this. Matrices are usually faster to manipulate than cells, ...

9 dagar ago | 0

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