Matt J
Professional Interests: medical image processing, optimization algorithms
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A function does not work with an array as an input argument
args={'ArrayValued',1}; MyFun = @(a, x) ( integral(@(k) k .* (1 ./ ( 1 + (a*k - x).^2 )), -1, 1,args{:}) ./ ... integral(@(k...
10 hours ago | 1
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Rounding errors when using quadprog
There's nothing wrong with post-rounding, however setting lb(i)=ub(i)=0 for the appropriate variables should force them to an ex...
11 hours ago | 0
Connect the optimizer function to data extracted from another software
You've written a fitness function f=@(~) e_and_r_vals(md_e,E_best_vals_from_md_r) which takes no input arguments. The fitness ...
17 hours ago | 0
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Is there an alternative to eval in a struct?
Your data organization seems like it should be reconsidered. In a struct, it doesn't make sense if different fields have essenti...
1 day ago | 0
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Expressing polynomial including a indefinite parameter
Possibly you mean that you want a coefficient vector as the output, rather than a polynomial in functional form. syms a x P ...
1 day ago | 0
Expressing polynomial including a indefinite parameter
One way. p = @(x,a) polyval([a,-4,2-a],x); Usage: x=1; a=2; p(x,a)
1 day ago | 1
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Combining 3 2D graphs into a 3D figure
Something like the following, perhaps? x=linspace(0,5); z1=x.*exp(-x); z2=3*x.*exp(-4*x); Hax=axes; area(x,z1,'Parent',up...
1 day ago | 0
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How can I minimize absolue value in a power optimprob?
The objective is to minimize the integral of Pgrid abs value... while the control variables are Pbatt and Pev; Ppv and Pload If...
1 day ago | 0
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Finding out what initial guesses the curve fitting toolbox made for curve fit
I don't think there's anyway to dig out the initial guess generated inside fit(), but why not just specify your own random start...
2 days ago | 0
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When I export the figure, the x-axis is halved even though I have set the interval in the code.
I usually use export_fig(), https://github.com/altmany/export_fig
2 days ago | 0
How to fill a hollow donut-shaped object so that it looks like a circle?
load Image montage( {BW, imfill(BW,'holes')}, [],'Back','w','Bor',5)
2 days ago | 0
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Is there a way to set MaxSQPIter for active-set algorithm under fmincon?
Probably because you didn't pass options to fmincon. Otherwise, show us your code.
2 days ago | 1
histc problem in counting in particular bin
You are assuming that the bin boundaries are calculated with infinite precision, which is impossible. Likewise your data is also...
2 days ago | 0
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Replace value that are associated to a location by nan
spl(0<= elevation & elevation<=100)=nan;
2 days ago | 0
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Fit dataset to another dataset
See polyfit(). https://www.mathworks.com/help/matlab/ref/polyfit.html
3 days ago | 0
optimization of matrices with random initialization
Make sure your objective function code does not contain any randomization steps. Your initial guess can be random, but the objec...
3 days ago | 0
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What dose this function mean and what is the differentes ?
The first is calculating the number of zeros in B and the second is summing all values in B (times -1).
3 days ago | 0
Error in lsqcurvefit with 3 unknown parameters involved
If your model has 3 unknown parameters, then your initial guess P40 must be a vector of length 3.
3 days ago | 0
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sum only consecutive 1's in matrix
See, Tools for Processing Consecutive Repetitions in Vectors https://www.mathworks.com/matlabcentral/fileexchange/78008-tools...
3 days ago | 0
what is the fastest appproach to solve a system of non linear equations ?
Seems like it would make sense to regard this as a system of 100K simultaneous equations and solve for the PDE parameter with ls...
3 days ago | 0
How do we allocate equidistant points on a sinusoidal curve?
You should also have a look at interparc() https://www.mathworks.com/matlabcentral/fileexchange/34874-interparc?s_tid=srchtitle...
3 days ago | 0
How do we allocate equidistant points on a sinusoidal curve?
You can use fzero, x_p=0; y=@(x) -25*sin((2*pi/50)*x); fun=@(d) d.^4+( y(x_p+d^2)-y(x_p)).^2 - 0.004^2; x=x_p+fzero(fu...
3 days ago | 1
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drawrectangle draws rectangle even though the mouse is clicked outside the parent UIAxes
You can fall back to imrect, if necessary fcn = makeConstrainToRectFcn('imrect',get(gca,'XLim'),get(gca,'YLim')); h=imrect('Po...
3 days ago | 0
Array processing using Taylor Series and FOR Loops to approximate sin value for each element in that array.
The array can be of any type and dimensions. If so, why does your code assume it will be 2D? Can't it be 3D or 4D? In any case...
4 days ago | 0
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How to store iterative information to a matrix?
The following is pretty typical. result=nan(big_number,1); while abs(y)>=small_number &iteration<big_number [x,y] = some...
5 days ago | 0
how to generate points inside a rectangle not parallel to axis in Matlab
You mean you want to generate N random points? If so, then, xy=Q*([length;width].*(rand(2,N)-0.5)) + center(:)
5 days ago | 0
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