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# Matt J

6,200 total contributions since 2009

Professional Interests: medical image processing, optimization algorithms

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Single precision matrix multiplication
The Matlab interpreter runs a special dedicated "ctranspose-multiply" function to evaluate expressions of the form, P'*Q It do...

15 hours ago | 1

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Non linear fitting with constraints
You would have to use fmincon, which will let you specify non-linear constraints.

17 hours ago | 0

imwrite does not save file in specified folder :(
Try this, dest=fullfile(newpath, ['new_' file(k).name(1:end-4) '.jpeg']); imwrite(I,dest);

20 hours ago | 0

Using lsqcurvefit in a Matlab App
Here is a snippet of the code I am working with. No, the code should look like this, methods (Access = private) %...

1 day ago | 0

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Fit sum parameters of an overdetermined system
Your xdata should be a 9x11 matrix, your ydata should be a 1x11 vector, and the code for your function should look like this, f...

2 days ago | 0

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Not (~) operation of binary image after subtracting double data type of binary images. Could I have the explaination of this?
If im1 and im2 start off as uint8, then subtraction operations 0-1 will yield zero values, >> uint8(0)-uint8(1) ans = u...

2 days ago | 1

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How to separate a variable out of trigonomic expression
These identities may help,

2 days ago | 0

Unable to perform assignment because the left and right sides have a different number of elements error
It's because in that line, b is not a scalar, even though everything else is:

3 days ago | 0

Does anyone know the process of solving this problem?: "Write a MATLAB command to plot 5 cycles of s=sin(1000t)."
This very similar example may be of some help, https://www.mathworks.com/help/matlab/ref/plot.html#btzitot-4

3 days ago | 1

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least square circle, why doesn't it work?
As I mentioned in your other post, your approach is not a good way to fit a circle. However, assuming you must do it this way, y...

3 days ago | 1

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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...

4 days ago | 2

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...

4 days ago | 0

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Submitted

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

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

4 days ago | 0

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

4 days ago | 0

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

4 days ago | 1

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

4 days ago | 1

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Convert matrix 3d into 2d

4 days ago | 1

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

6 days ago | 0

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)^...

6 days ago | 0

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 ('...

7 days ago | 0

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

7 days ago | 0

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 ...

7 days ago | 0

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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...

7 days ago | 0

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...

7 days ago | 0

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 ...

7 days ago | 1

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

7 days ago | 0

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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...

7 days ago | 0

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