Community Profile # Matt J

Last seen: Today Active since 2009

Professional Interests: medical image processing, optimization algorithms

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Efficiently assigning class property in a quadruple loop?
You've not told us the dependence of myLogicalVector and someFixedValue* on the loop variables, which is probably super-importa...

1 día ago | 0

Double Summation without using fft2 function
You can find examples of for-loop construction here, https://www.mathworks.com/help/matlab/ref/for.html#buhafgy-3

1 día ago | 0

Sequence 1, 2, 4, 12
One possibility: p=[0.833333333333333 -4.499999999999996 8.666666666666661 -3.999999999999996]; polyval(p,1:4) polyval(...

2 días ago | 0

How to get optimal linear scaling factor for a set of vectors
I want to determine a linear scale factor for each y_raw? vector, such that the mean squared error (MSE) between the average of ...

2 días ago | 0

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Linear Equations infinite solutions parametric form
x0=pinv(A)*b; B=null(A); sol=@(c)x0+B*c;

2 días ago | 1

| accepted

Submitted

Further tools for analyzing objects in N-dimensional images
A collection of tools to supplement bwpropfilt, bwareaopen, and the like.

How can I speed up (or avoid) a comparison in for loop?
You might try bwlareaopenn from this submission https://www.mathworks.com/matlabcentral/fileexchange/90762-further-tools-for-an...

3 días ago | 1

Solver based optimization passing extra parameters

3 días ago | 0

How to get the file names that start with the same letter in the folder?
For example, s=dir('T*_imag.bin'); fileNames={s([s.isdir]==0).name}

3 días ago | 0

Matrix form for creation and annihilation operator with spins.
Not sure this will help, but if you can write a function that implements the operator, then his File Exchange offering, https:/...

3 días ago | 0

What should go in a next-generation MATLAB X?
My wish list: (1) Colon operator produces column vectors, not row vectors: x=1:4 (2) Optimization Toolbox solvers should ha...

3 días ago | 2

combine different size vectors into one matrix
I will assume you have the vectors in a cell array C={[2 3 4 5]; [4 7 7]; [8 8 7 4 2 5]} Then, you can simply do, z=...

3 días ago | 0

using fsolve function to solve for 2 unknowns
x0 = [80,110]; [sol, Fsol] = fsolve(@problem_one,x0), function F = problem_one(theta) theta3 = theta(1); theta4 ...

4 días ago | 1

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fminunc initial point is local minimum, but fminsearch returns reasonable estaimtes
It could happen if your objective function is piece-wise flat (and hence non-differentiable). fminsearch is a derivative-free so...

4 días ago | 0

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How can I obtain the Fourier Transformation as a product of matrices?
N = (0:255).'; X = (2*cos(((15.8*pi)/128)*N)) + (3*sin(((27.3*pi)/128)*N)); F=fft( eye(numel(X)), [],1); fX = fft(X); %...

4 días ago | 0

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How to plot binary matrix as dots?
imshow(yourMatrix)

4 días ago | 0

Solving non linear equation "Circle" equations
Because you cannot be certain of an exact 3-way (or n-way) intersection, you need to use a numerical least squares solver like f...

5 días ago | 1

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What is the real value of "single(my_variable)"?
So the C code keeps good precission. But, does Matlab? Yes, if by "good precision" you mean up to 7 digits. You can see that ev...

5 días ago | 0

How to define a constat in function handle?
You mean like this? [a,b,c]=deal(3,4,5); f = @(x,y)a*x.^2+b*y+c Or like this? syms x y a b c f(x,y) f(x,y)=a*x.^2+b*y+...

5 días ago | 0

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Steepest descent with exact line search method
n=input("Enter the roll number:"); fobj=@(x) (x(1)-n)^2 + (x(2)-2*n)^2; gradobj=@(x)2*[(x(1)-n), (x(2)-2*n)]; x0=[1 1]; ...

5 días ago | 0

how to develope loop to save the 'n' elements from the vectors
It is not a good idea to store A(i) in separate variables. You should probably just write your equation in terms of vector opera...

5 días ago | 2

Taylor series approximation problem
As an example, syms x T=taylor(exp(-x),x,7,'Order',4) fn=matlabFunction(T) fn(3) You can of course find more examples...

5 días ago | 0

how can I call a class in a gui?
I have defined a class TimeData by a script Don't you mean you defined it in a classdef file? The constructor function for a c...

5 días ago | 0

Trying to supply fsolve with system's Jacobian but receiving error ''check for incorrect argument data type"
It is not clear (from what you posted), why you are using symbolic variable manipulation at all. fsolve is a numerical solver, n...

5 días ago | 0

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Rotate Values of Matrix
Use imtranslate() to center the source in the image, then use imrotate() it by the desired angle, then use imtranslate() once mo...

5 días ago | 0

Get the last for digits as the time this message was sent
Is this what you want? str=char( "!AIVDM,1,1,,A,13cut>1001P:3LRGa`P@jip400S<,0*410002" ) str(end-3:end)

5 días ago | 1

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Is it possible to set an upper limit on the step size used by fsolve?
You could try playing with the InitDampling option parameter used by the Levenberg-Marquardt method.

6 días ago | 0

Am I understanding this correctly?
If by "low" you mean zero and by "high" you mean 255, then yes.

6 días ago | 0

Not sure why while loop won't run.
balance(1) = 1000; contribution = 1200; interest = 0.0025; M = 2; % month ticker while balance(end) < 500000 ba...

6 días ago | 2

| accepted