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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
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

Answered
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

Answered
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

Answered
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

| accepted

Answered
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

Answered
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

Answered
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

| accepted

Answered
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

| accepted

Answered
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

Answered
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

Answered
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

| accepted

Answered
Add dimensions to a matrix
[RHSval,kprimeind] = max(RHSvec,[],2,'linear'); kdpolind(act,kprimeind)= vector_that_is_51x1

4 días ago | 0

Answered
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

Answered
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

| accepted

Submitted


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

5 días ago | 9 downloads |

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Answered
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

Answered
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

| accepted

Answered
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

Answered
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

Answered
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

| accepted

Answered
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

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

7 días ago | 0

| accepted

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

8 días ago | 0

Answered
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

Answered
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

| accepted

Answered
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

Answered
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

| accepted

Answered
how can I have a perfect rect function as the result of applying fft on sinc function?
I want exactly a rectangle like what we have in theory. The FFT of a sinc function is not a perfect rect, even in theory. The ...

8 días ago | 1

Answered
Plotting from function per for-loop iteration
If you want new figure windows for each plot, don't specify a number for them: figure scatter(x,y) figure scatter(x+y,y)

9 días ago | 1

| accepted

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