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Matt J


Last seen: Today |  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
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

Answered
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

Answered
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

Answered
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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answer

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

en dag ago | 1

| accepted

Answered
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

Answered
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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Answered
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

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

4 dagar ago | 0

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Answered
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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Answered
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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Answered
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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Answered
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

Answered
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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Answered
Fzero giving weird answer
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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answers

Answered
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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Answered
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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Answered
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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Answered
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

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

7 dagar ago | 0

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Answered
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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Answered
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

1

answer

Answered
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

Answered
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

Answered
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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