Community Profile

# 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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Using optimization algorithms to find minimum path with obstacles
It's doubtful you can do it with fmincon, but you might be able to do it by creating a graph object to model steps between allow...

9 hours ago | 0

Align and stitch non-overlapping images
As seen from here, the blocks of 32 measurements can be slightly shifted vertically by few(1-4) pixels, So, wiuth 4 blocks and ...

13 hours ago | 1

3D cylinder code debugging
Much of your code seems to be an unnecessary reinvention of the cylinder() command. nCS = 2; %number of cross section of cylind...

15 hours ago | 1

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Different output for find(X) and find(X<5)
Because the argument you've passed to find() is (X>0) which is a logical array. Therefore, the values returned are taken from th...

15 hours ago | 1

Error 'lscurvefit' (Function value and YDATA sizes are not equal)
Since you have no bounds on K, you should probably just solve for K analytically, rather than iteratively with lsqcurvefit: K=(...

1 day ago | 0

Error 'lscurvefit' (Function value and YDATA sizes are not equal)
f = @(K, x) K(1) + K(2)./ x + K(3)./ x.^2;

1 day ago | 0

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Rounding a decimal down
x=0.147; floor(x*100)/100

1 day ago | 1

How to store the results of a loop in matlab.
[B,C,m,k,c]= deal(cell(1,20)); A=nan(1,20); for t = 1:20 z=t-1; m{t}= [1.0, 0.89*sin(0.17*z); 0, 1...

1 day ago | 0

How to assign point name to points in an array and then plot them ?
names={'Jack','Fred','Emily','Carol','Donald'}; A = [0,1.5+1.5i,4.5i,-6.75+6.75i,-20.25]; n=numel(A); H=plot(graph(speye(n)...

2 days ago | 0

How to assign point name to points in an array and then plot them ?
Hi all, I would like to name my points that are inside a matrix. You could convert the matrix to a table with row names that yo...

2 days ago | 1

Can a function known whether/which specific output is ignored (tilde operator)?
You can do it with this FEX download, https://www.mathworks.com/matlabcentral/fileexchange/121487-outputnames but there are so...

2 days ago | 0

Equivalent of inputname() for output variables
I've implemented Jan's idea in this FEX submission, https://www.mathworks.com/matlabcentral/fileexchange/121487-outputnames b...

2 days ago | 0

Submitted

outputnames
Get a list of the output argument names of the currently executing function.

Question

Why doesn't evalin('caller','nargout') work?
Why doesn't the mynargout() function correctly return n=3? How can one programmatically evaluate nargout in the calling functio...

3 days ago | 1 answer | 0

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Numerical calculation of Hessian for a very complex problem
but this neighboorhood might be super small region about x0 and I do know how small it is. I assume you meant to say you don't ...

3 days ago | 0

making a connectivity array for an ellipse based of rectangles and traingles

3 days ago | 0

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How to remove NaN from matrix / remove the dark blue pixels in the ocean
You can't remove the NaNs and keep the original rectangular shape of the matrix without replacing the NaNs with another value, e...

3 days ago | 0

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Efficient way of Vectorization
Unfortunately, this is a situation where the for loop is the fastest option. This is because vectorized solution does much more ...

4 days ago | 1

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how extract two arrays in matlab of unequal length
Yes interp1 to sample the curves at corresponding points. Then you can subtract them freely.

4 days ago | 0

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initial point is a local minimum. Optimization completed because the size of the gradient at the initial point is less than the default value of the function tolerance.
I suspect your FiniteDifferenceStepSize is too small. Be mindful of the guidelines for Optimizing Differential Equations.

4 days ago | 0

Parameters seem to not be optimizing in fmincon
If the exitflag says a minimum was found then there is probably nothing suspect about the solution or the way it was reached. Th...

4 days ago | 0

defining state matrix as anonymous function
For example B = @(I1,L)[0 0 1/(I1) 0 0 0 0 0 0 -1/L]; B(2,1)

4 days ago | 0

How to save multiple matrices in each iteration of a for loop into a structure?
clear S for k = nLevels:-1:1 S(k).subband = pyrBand(pyrRef, pind, k); S(k).rx = conv2(subband(k),kernelx); S(k)....

5 days ago | 0

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Error in interpolating: Actual data does not match with interpolated data
load inputData i=11; j=3; %query points (Lat and Alt) %% interpolate LUT1=griddedInterpolant(Long1c_4d,Lat1c_4d,Alt1c_4...

5 days ago | 1

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How to close boundary of a circular object in binary image

5 days ago | 0

How to find and fit the objective function for a damped oscillation?
Using fminspleas from the File Exchange, https://www.mathworks.com/matlabcentral/fileexchange/10093-fminspleas [t,F]= readvar...

5 days ago | 2

interpolation of a structure array
fcn=@(f)interp1(f, linspace(1,numel(f),101) ); for i=1:numel(TrajXLstance) TrajXLstance(i) = structfun(fcn, TrajXLs...

5 days ago | 0

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Finding min and max values in a structure
each field consisting of a cell of numbers If you really do mean a cell array, that seems like an inadvisable organization of t...

5 days ago | 0