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Matt J


6.190 total contributions since 2009

Professional Interests: medical image processing, optimization algorithms

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Answered
Non linear least square fitting
Ok. Could you possibly show me the analytical alternatives to Adam's solution? See attached. Note that my method does not mini...

ongeveer 9 uur ago | 2

Answered
How can I use graph object info to find: areas, number of sides, and perimeter lengths of a each connected polygon within a network of polygons?
Using one of my recent FEX postings, https://www.mathworks.com/matlabcentral/fileexchange/73630-spatialgraph2d you should be a...

ongeveer 10 uur ago | 0

Submitted


spatialgraph2D
Creates a graph object with 2D spatial locations associated with the nodes

ongeveer 10 uur ago | 0 downloads |

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Answered
return the numerator and denimentor
If x is a symbolic variable, then yes >> x=sym(1/2); >> [n,d]=numden(x) n = 1 d = 2

ongeveer 12 uur ago | 0

Answered
vectorize high dimensional image
result = reshape(yourImage,[],102).';

ongeveer 13 uur ago | 0

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Answered
Using functions relating polynomial
result = conv(P,Q)

ongeveer 13 uur ago | 1

Answered
How to replace elements of a matrix with the scaled identity?
B=kron(A,eye(n))

ongeveer 13 uur ago | 1

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Answered
Convert matrix 3d into 2d
Calling your matrix A, Acell=num2cell(A,[1,2]);

ongeveer 13 uur ago | 1

Answered
Find an optimal solution for a system with matrix
f=-A(:); Aineq=[B(:),C(:)].'; bineq=[4;3] Xoptimal=linprog(f,Aineq,bineq)

2 dagen ago | 0

Answered
Trying to plot Eulers, but keep getting straight line
You're getting a straight line because the right hand side of this line acmi(1:10001)=-a+(alpha(n)*l*cos(theta(n)))-((omega(n)^...

3 dagen ago | 0

Answered
how to write a function for quadratic equation
[x1,x2] = QuadraticEquation (1,-2,0) function [x1,x2] = QuadraticEquation (a,b,c) d=b^2-4*a*c; if d>=0 disp ('...

3 dagen ago | 0

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Answered
How to sum a series of numbers?
sum(numerator./denominator)

3 dagen ago | 0

Answered
multi-variable optimization in matlab?
Many other variables are to be calculated first, which are actually functions of the first two variables, and then they're used ...

3 dagen ago | 0

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Answered
Call a function in a sub directory?
The only way, I believe, is to visit each folder and create a function handle to each respective version of sayhi(), cd folder1...

3 dagen ago | 0

Answered
Map a 2D matrix into 3D using loop for allotment along the 3rd dimension
You could try this. clear data_trialwise for i=20:-1:1 data_trialwise(:,:,i)=data(:,begin(i):end(i)); % begin and end bot...

3 dagen ago | 0

Answered
shifted triangular matrix array
ac=num2cell([0,0;a],2); T=toeplitz(1:4,[1,zeros(1,3)]); A=cell2mat(ac(T+1)) A = 1 2 0 0 0 ...

3 dagen ago | 1

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Answered
How can i multiply cell arrays?
for i=1:2 for j=1:2 H{i,j}=H{i,j}.*X{i}; end end

3 dagen ago | 0

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Answered
Most efficient way to enter values into pre-allocated sparse matrix?
I would just store all the data from the loop calculations in cells. Then use the data to build the sparse matrix after the loop...

4 dagen ago | 0

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Answered
Is possible configure matlab to get a+[ ]=a?
You could also replace your plus() operations with sum() operations. Compare: >> a=3; b=[]; >> a+b ans = [] >>...

5 dagen ago | 1

Answered
Is possible configure matlab to get a+[ ]=a?
No way that you're going like. You could subclass Matlab's double type https://www.mathworks.com/help/matlab/matlab_oop/extend-...

5 dagen ago | 1

Answered
Error using griddedInterpolant The grid vectors do not define a grid of points that match the given values.
You have 20 Y samples, but your V has 21 rows. >> whos X Y V Name Size Bytes Class Attributes V ...

5 dagen ago | 0

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Answered
Average of every nth value in a vector
tmp=conv(yourvector, ones(600,1)/600,'valid'); result=tmp(1:600:end)

6 dagen ago | 0

Answered
Add two lines to a matrix.
A=A([1;2;3;3;3],:)

6 dagen ago | 0

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Answered
3-D line of best fit from origin to cloud of data points
The equation is t*u where u is 3D line direction vector obtained by, [V,d]=eig(A.'*A,'vector'); [~,i]=max(d); u=V(:,i); and ...

6 dagen ago | 0

Answered
Multi-function optimization
You would need something like the following, options=optimoptions(@fminunc,'SpecifyObjectiveGradient', true); allX = fminunc...

6 dagen ago | 0

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Answered
2D Convex Hull: I can't think of a 'criteria' to filter out the 'wrong' points, please help!
One thing you can also try to do is find where one of the rays from the pivot point lies inside the triangle formed by its two n...

7 dagen ago | 0

Answered
Radon Transform Documentation Matlab
I understand the Radon Transform get the product between the length(intersection) of each beam through the pixel and the pixel ...

7 dagen ago | 1

Answered
Why do the values not get added into the array such as [2,3,5,7], but instead they get summed up?
Because you are using '+'. To concatenate, you would do, values = [values, tester];

7 dagen ago | 0

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