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Matt J

Last seen: Today Active since 2009

Professional Interests: medical image processing, optimization algorithms

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Optimisation functions: Skipping iterations if objective function returns an error or cannot run completely
Basically, the option available to you is to return inf from your objective when an error condition is reached. Some optimizatio...

alrededor de 14 horas ago | 0

fill a vector (efficiently) with values specified by matrix and multiple vectors
M=reshape(1:8,2,2,2);N=10; x=(rand(N,1)>0.5)+1;y=(rand(N,1)>0.1)+1;z=(rand(N,1)>0.1)+1; OUT=M( sub2ind(size(M),x,y,z) ...

alrededor de 14 horas ago | 0

Interpolating points in a 3D space with one line
You can use linear3dFit() from this FEX submission https://www.mathworks.com/matlabcentral/fileexchange/87584-object-oriented-t...

1 día ago | 1

how to handle soft weight constraints in neural network
If you wish to train with standard unconstrained stochastic gradient descent algorithms, you will probably have to make a custom...

1 día ago | 0

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Convert decimal and negative values ​​to integers
Something like this, perhaps? a = 0:pi/100:2*pi; x=cos(a); y = sin(x); fcn=@(z)round(rescale(z,0,intmax('uint16'))); pl...

1 día ago | 0

why do we need to flip kernel before using conv2 in CNN?
The field of neural networks uses the term "convolution" loosely. There are other differences as well. We also know that in trad...

1 día ago | 0

Applying the Nonlinear Least Squares Method to Minimize the Objective Function to Find the Parameters of the Equation
Your code makes strange assumptions about the output syntax of lsqnonlin. [x,resnorm,residual,exitflag,output,lambda,jacobian] ...

2 días ago | 0

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Trying to solve a matrix with four equations and four unknowns. Should be three non zero terms.
You cannot paste a function definition into the command window. Put it in a file and run it in the Maltab editor. Also, you are ...

2 días ago | 0

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How I can separate the data points by line?
You could use fitclinear. To illustrate, I will use fabricated data: %synthetic data N=500; Resistivity=rand(N,1); Porosity=...

2 días ago | 0

Create a sliding window
matrix=reshape(vector,5e5,[]) This gives a matrix whose i-th window is matrix(:,i). How best to process that, though, depends o...

4 días ago | 0

A*1 and A+0 could be faster.
My sense of things is that, in the situations where you would care about such special case optimizations, you would know in adva...

4 días ago | 1

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[RHSval,kprimeind] = max(RHSvec,[],2,'linear'); kdpolind(act,kprimeind)= vector_that_is_51x1

4 días ago | 0

Why do I receive the array indices must be positive intergers or logical values
You haven't provided the input necessary to run your code, but it looks like tempo_fix-60 could be <=0.

4 días ago | 0

Calculate the value of an area around a known co-ordinate
mean(Thermal(y-1:y+1,x-1:x+1),'all')

5 días ago | 0

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Submitted

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

Interpolation of the values of points on the surface created by convex hull
For example, was the question targeted at sampling new points on the surface...? Assuming that's the correct interpretation, th...

5 días ago | 0

how to range data and find maximum value for each range by using loop
AB=[1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16; 10 5 7 8 3 18 20 3 6 66 2 14 39 40 4 20].'; [maxval,i]=max(reshape(AB(:,2),4,[]),...

5 días ago | 0

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Generate Field Names from Variables While Accessing Elements of a Nonscalar Structure Array
Why not a 2D struct array, R(nDriver,1).LapData(nLap).LapTime R(nDriver,2).LapData(nLap).LapTime R(nDriver,3).LapData(n...

5 días ago | 0

How to find the index of a particular child when using use parallel = True option in genetic algorithm optimizer?
If you have the Parallel Computing Toolbox, set UseParallel=false and UseVectorized=true. Then, inside your objective function a...

6 días ago | 1

How can i solve this cost function?
v = [(1 / (0.47 * 0.94 * 1500)^2) (1 / (0.47 * 0.94 * 1700)^2) (1 / (0.47 * 0.94 * 2000)^2) (1 / (0.47 * 0.94 * 2200)^2)]; delt...

7 días ago | 1

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Text comparisons no longer work with arrays in 2022a
There's been no change. cell arrays containing character vectors still work: contains({'dog','fish','cat'},'cat') What does no...

7 días ago | 1

How to find the constant of a line function
Evaluate the function at x=0.

7 días ago | 0

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Min of each column of a sparse matrix?
result = -log( max( spfun(@(x)exp(-x), yourMatrix) ,[],1) );

8 días ago | 0

Create random numbers inside a specific plane in xy plane
I don't understand how you are specifying your parallelograms. However, one way is to use ndgrid and then apply a shear: [X,Y]=...

8 días ago | 0

Generating all unique binary vectors of length N given certain criteria
N=5; A=triu(ones(N)); B=~eye(N); B=B(2:end-1,:); c=nchoosek(2:N-1,2); C=(1:N); C=C<c(:,1)|C>c(:,2); result=...

8 días ago | 0

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How to join or merge two Image Data Stores?
Perhaps by wrapping them in a TransformedDataStore (R2019a and higher), imdsnew = transform(imds1,imds2, @(x) x)

8 días ago | 0

Can i continue to run my matlab programs even when the computer screen is locked using Win+L
Yes, it will continue to run.

8 días ago | 0

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