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Matt J


5.790 total contributions since 2009

Professional Interests: medical image processing, optimization algorithms

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Answered
Visualise direction 3D vector defined by two angles
How about something like this, [u,v,w]=sph2cart(-angle1*pi/180 , pi/2-angle2*pi/180, 1); quiver3(0,0,0,u,v,w)

ongeveer 15 uur ago | 0

| accepted

Answered
How to perform the absolute value function on the output of an optimisation expression?
Without seeing your complete problem, it is hard to be certain, but you might find minL1lin (File Exchange download) applicable ...

ongeveer 18 uur ago | 0

Submitted


minL1lin
Constrained minimum L1 norm solution of linear equations C*x=d

ongeveer 18 uur ago | 5 downloads |

Answered
Get handle of (non graphics) object
The only way I can think of to implement something like that is using persistent variables, like in the classdef below. The work...

ongeveer 19 uur ago | 0

Answered
Get a property from a class
All you have to do is change the SetAccess property attribute, e.g., properties (SetAccess=private) fullFileName ...

ongeveer 19 uur ago | 0

Answered
Dynamic Array update without for loop
X=0.9*(A(1:end-1)-B(2:end)); Out=[0; filter(1,[1,-0.1],X)];

ongeveer 20 uur ago | 0

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Answered
distance between 2 no-parallel planes
If you mean that you want the minimum separation between the planes over some bounded (X,Y) rectangle, then just check the separ...

ongeveer 22 uur ago | 0

Answered
Issue about "the same lower bound and upper bound" in 'fmincon'
No, it is not wrong. It probably means you have multiple solutions or that the differences are merely floating point noise. You ...

1 dag ago | 0

Answered
How to fit some curves to one curve in which only the maximum of curves are fitted?
Generate the maximum of all your curves and use alphashape() to smooth over concavities in its envelope.

2 dagen ago | 0

Answered
Using fmincon on a vector of anonymous functions
I would recommend that you implement E(A) through a non-anonymous function, as below. Note that I have changed your objective to...

4 dagen ago | 1

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Answered
find whole lines, not line segments, after hough transform
If you have the Computer Vision Toolbox, you can try RANSAC, as in this example https://www.mathworks.com/help/vision/ref/ransa...

4 dagen ago | 0

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Answered
estimate depth with two different focal lengths
Why should it matter that the focal lengths are different? There is nothing in the syntax of the triangulate command https://ww...

4 dagen ago | 0

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Answered
I would be grateful to receive some example of usage of builtin function 'regionprops'
Because I don't have R2019b, I had to run a somewhat modified version of the code S=load('BWCurve.mat','CBW'); BW=S.CBW; % Ge...

4 dagen ago | 0

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Answered
How to solve the problem about "Conversion to logical from optim.problemdef.OptimizationConstraint is not possible!"
Introduce variables r to represent bounds on Pbatt r=optimvar('absPbatt',simTime1,'LowerBound',0); prob.Constraints.r_upper=...

4 dagen ago | 0

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Answered
Fminsearchbnd vs. Pattern Search vs. Surrogate Optimzation to attempt to find the global optimal solution.
There is no way to predict the number of multi-starts you would need to make fminsearchbnd behave competitively with the other s...

4 dagen ago | 0

Answered
Is there a difference between declaring a class property "Dependent" versus "Dependent = true"?
Yes, they are equivalent. Also, you can do, properties(~Dependent) aProp end as an equivalent to, properties(Dependent=...

11 dagen ago | 1

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Answered
How to integrate an unbounded function?
You cantry use the symbolic toolbox, or you could just take the numerical integral over a sufficiently large finite interval. A ...

11 dagen ago | 0

Answered
Optimization solver: retrieval of Constraint matrices
Yes, use prob2struct, https://www.mathworks.com/help/optim/ug/optim.problemdef.optimizationproblem.prob2struct.html

11 dagen ago | 0

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Answered
Why output of rotation matrix in Camera Calibration is vector ? What do to convert to rotation matrix ?
A cameraParameters object also has a property that stores the rotations in matrix form https://www.mathworks.com/help/vision/re...

11 dagen ago | 0

Answered
Find constraints on polynomial coefficients optimization
It might be more natural here to use fseminf, x = fseminf(fun,[a1,a2,a3], 2, @(a,s) seminfcon(a,s,T,lb,ub)); function [c,...

12 dagen ago | 0

Answered
Find constraints on polynomial coefficients optimization
What's to figure out? You've already articulated that the (nonlinear) constraints on the extremum are, 0<=-a2/(2*a1)<=T The on...

12 dagen ago | 0

Answered
fmincon generating (very) noisy results - initial guesses probably to blame
If you're suspicious about the initial point, I would recommend MultiStart, or just try lots of different initial guesses yourse...

12 dagen ago | 0

Answered
Constraint of optimization problem
It's the wrong solver. You would need to use ga() for a problem like that.

12 dagen ago | 0

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Answered
How to normalise a FFT of a 3 variable function.
To normalize so as to obtain Discrete Fourier Series coefficients, divide by N=numel(input).

12 dagen ago | 0

Answered
How to normalise a FFT of a 3 variable function.
To normalize so that the continuous Fourier transform is approximated, multiply by the sampling intervals, dT1*dT2*dT3

12 dagen ago | 0

Answered
How to normalise a FFT of a 3 variable function.
To normalize so that Parseval's equation holds, divide by sqrt(numel(input)).

12 dagen ago | 0

Answered
Subtract according to the values in another column
[~,i]=unique([C1,C1(end+1)],'stable'); result = C2(i(2:end)-1)-C2(i(1:end-1))

12 dagen ago | 0

Answered
Can we use scatteredinterpolant in parallel
You can certainly divide queries into parallel batches, e.g., F=scatteredInterpolant(P,v); results=cell(size(batch)); parfo...

13 dagen ago | 0

Answered
Can parallel computing toolbox not parallellise over multiple CPUs?
12 is the upper limit if you are using a version of Matlab earlier than R2014a, see also https://www.mathworks.com/matlabcentra...

13 dagen ago | 0

Answered
Conditional Skip in for loop
Apply the suggestions in this thread to A=logical(x)+1.

13 dagen ago | 0

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