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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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Answered
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...

ongeveer 8 uur ago | 0

Answered
I have two arrays that I want to divide a specific way
C=A./B;

ongeveer 8 uur ago | 0

| accepted

Answered
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

ongeveer 11 uur ago | 0

Answered
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)

ongeveer 11 uur ago | 0

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Answered
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.

ongeveer 14 uur ago | 0

Answered
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...

ongeveer 14 uur ago | 0

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Answered
Replace value that are associated to a location by nan
spl(0<= elevation & elevation<=100)=nan;

ongeveer 14 uur ago | 0

Answered
Fit dataset to another dataset
See polyfit(). https://www.mathworks.com/help/matlab/ref/polyfit.html

ongeveer 20 uur ago | 0

Answered
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...

ongeveer 20 uur ago | 0

Answered
HOW TO REVERSE THE BINARY IMAGES
outt33(:,:,i) = ~imbinarize( I)

ongeveer 20 uur ago | 0

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Answered
How do I obtain FFT of nabla operator F(▽)?
nable=diff(eye(N)); %diff in operator form operator=fft(nabla.'*nabla);

ongeveer 20 uur ago | 0

Answered
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).

ongeveer 21 uur ago | 0

Answered
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.

ongeveer 21 uur ago | 0

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Answered
sum only consecutive 1's in matrix
See, Tools for Processing Consecutive Repetitions in Vectors https://www.mathworks.com/matlabcentral/fileexchange/78008-tools...

ongeveer 22 uur ago | 0

Answered
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...

1 dag ago | 0

Answered
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...

1 dag ago | 0

Answered
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...

1 dag ago | 1

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Answered
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...

1 dag ago | 0

Answered
create nononteger random matrix in certain range
200*rand(5)-100

1 dag ago | 1

| accepted

Answered
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...

2 dagen ago | 0

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Answered
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...

3 dagen ago | 0

Answered
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(:)

3 dagen ago | 0

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Answered
How do I add zero padding to this convolution?
Not sure what the question is, but you can easily compare your result to direct convolution to see if it's correct. x1x2_conv =...

3 dagen ago | 1

Answered
How to tell an multi-output anonymous function to vectorize its output components which are constant
One way, f=@(x,y) completeRows({x+y;2;x*y;x.^2-1;3}); f([1 2],3) function out=completeRows(C) n=max(cellfun('length',...

4 dagen ago | 0

Answered
Area between three curves
A=Einspeiseanteil; B=GabelstaplerP; C=max(A,B); area=trapz(X,(C-Y).*(C>=Y))

5 dagen ago | 0

Answered
How to plot vectors exactly on the edge of another graph?
t=linspace(0,360,91); t(end)=0; u=cosd(t); v=sind(t); fimplicit(@(a,b) a.^2+b.^2-1);hold on quiver(u,v,u,v,'Color','r...

5 dagen ago | 1

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Answered
How can I assign values to min/max of a column within each value of another column?
Let's call your table T, then, T=table(randi(2,10,1), randi(100,10,1), rand(10,1),'V',{'Device','Time','current'}) str=[""...

5 dagen ago | 0

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Answered
min and max optimization as a single minimization function
if i am adding these function together like as follows min(f)=(1/f1)+f2 will it be correct? can i get the proper result? The s...

6 dagen ago | 0

Answered
4D matrix multiplication
steer=reshape( permute(steer,[2,3,4,1]),101^2,[],136 ); R=permute(R,[2,3,1]); F=1./sum( pagemtimes(conj(steer),R).*steer, 2...

6 dagen ago | 0

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Answered
plotting two lines intersecting at a certain point
This is equivalent to a first order free-knot spline fit. This FEX submission might be useful, https://www.mathworks.com/matlab...

6 dagen ago | 0

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