Community Profile # Matt J

Last seen: Today Active since 2009

Professional Interests: medical image processing, optimization algorithms

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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 ...

environ 13 heures 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=...

environ 15 heures 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...

1 jour 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...

2 jours ago | 1

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

2 jours ago | 0

How to represent a curve with straight line segments?
You can add individual line segments to a plot with the line command, e.g, for i=1:5 line(rand(1,2),rand(1,2)); end

2 jours 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.

3 jours ago | 0

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

3 jours 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...

3 jours 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,[]),...

4 jours 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...

4 jours 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...

4 jours 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...

5 jours ago | 1

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Text comparisons no longer work with arrays in 2022a
There's been no change. cell arrays still work: [tf,loc]=ismember('cat',{'dog','fish','cat'})

6 jours ago | 1

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

6 jours ago | 0

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

6 jours 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]=...

6 jours 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=...

6 jours 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)

6 jours 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.

6 jours ago | 0

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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 ...

6 jours ago | 1

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)

8 jours ago | 1

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How to find intersection points of multiple line segments in 3D?
If you generate them randomly, they will not intersect. However, generatig and plotting them is no problem, numlines=5; for ...

8 jours ago | 0

matlab function on a grid along third dimension
No, you can't. However a 3x3x3 array is too small for a loop to suffer any serious penalties.

8 jours ago | 0

How to eliminate the elements in an array from another array when there are repeated elements in both arrays?
A = [ 1,2,2,2,3,4]; B = [1,2,2,3]; Au=[unique(A),inf]; reps=max( histcounts(A,Au)-histcounts(B,Au) ,0); C=repelem(Au...

8 jours ago | 0

Restricting solutions using lsqnonlin with complex unknowns
l1,L2,L3 are complex numbers, where the real and imaginary part are two sepparate unknowns, If so, then you have 12 unknowns, ...

8 jours ago | 0

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