Matt J

Last seen: Today

7.706 total contributions since 2009

Professional Interests: medical image processing, optimization algorithms

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Answered
How to draw 2D object with plot 3D matlab
The command cylinder() will be helpful. This example in particular, https://www.mathworks.com/help/matlab/ref/cylinder.html#mw_...

42 Minuten ago | 0

Answered
How to add uniform noise to image with median and standard deviation
I've never heard of "noise" with non-zero mean/median, but generating it is straightforward, delta=standardDeviation*sqrt(12); ...

etwa 3 Stunden ago | 0

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Answered
How to Check if a cell equals a word in a table
As an example, x=cell2table({'dog','paper','cat','fish','paper'}.') paper=nnz( string(x{:,1})=="paper") otherstuff=size...

etwa 4 Stunden ago | 0

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Nested objects - do or don't?
Ultimately, it depends on the situation and the data access patterns that you are going to need. As a rule of thumb, I don't thi...

etwa 10 Stunden ago | 1

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How to call columns of matrices using 'for loop' ?
for i=1:3 Approx{i}= U(:,1:i)*S(1:i,1:i)*V(:,1:i).'; end

etwa 10 Stunden ago | 0

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Answered
How to modify selected rows of one variable in table
fun=@(c) interp1(IzeroAugInCell(:,1),IzeroAugInCell(:,2), c); ListNexafs.uhvI0(tmpMatch) = cellfun(fun, ListNexafs.xRayEkin_e...

etwa 11 Stunden ago | 0

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Answered
How can I delete the rows if they have a NaN value?
keep=~isnan(x); x=x(keep); y=y(keep);

etwa 12 Stunden ago | 0

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Answered
calculating with many different parameters
I want to plot y with 1 value from z, 1 value from a, while showing all result for x = [1 2 3]. To me, this sounds like you ar...

etwa 12 Stunden ago | 1

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gpu computing and parallel computing (vectorize code)
b=max(0, floor( (1e4-S)/dt) )*dt + S;

etwa 12 Stunden ago | 0

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set extrapolation to connect last point values to the first (extrapolated) ones with interp1
Is this what you want? y = [788.54 827.7 846.66 960.09 136.16 53.991 36.994 904.47 882.32 1417.8 1191.6 154.91]; x = [15 45 74...

etwa 23 Stunden ago | 0

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Answered
FZERO error with matrix dimensions
You can trap the occurrence of the error using dbstop if caught error

ein Tag ago | 0

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Answered
separate connected component in two or more regions based on certain criteria
bwareaopen will accomplish item (1) straightforwardly. Other than that, since you haven't committed to a precise separation crit...

ein Tag ago | 0

Answered
How to use splitapply with fitlm
Your regression(y) function takes an argument y that is never used.

ein Tag ago | 0

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Answered
Plotting a non linear equation.
You could try fimplicit, https://www.mathworks.com/help//matlab/ref/fimplicit.html

ein Tag ago | 1

Answered
Max and Min for every change of integer?
Using your example, data=[1 8 0 1 10 0 1 12 0 2 10 8 2 11 10 2 0 12 3 0 5...

ein Tag ago | 1

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Answered
guesses of parameters in fmincon do not satisfy the constraints in nonlcon
Did fmincon report successful convergence? The code you've shown doesn't call fmincon with the exitflag output or show the exit ...

ein Tag ago | 0

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Answered
Multiple faces merging into a single face when using alphaShape()
If you have R2020b, I think you can just do this: n=9;% The number of sides of the polygon m=0:n-1; rootvec=10*exp(1i*2*pi*m/...

2 Tage ago | 0

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Answered
Multiple faces merging into a single face when using alphaShape()
I'm not familiar with how geometryFromMesh works, but using lcon2vert (which you must Download), you can generate a cell array c...

2 Tage ago | 0

Answered
fminunc throws an error; can't access source of error
Since you are apparently trying to fit a Gaussian lobe to your data, you might find it helpful to use gaussfitn (which you must ...

2 Tage ago | 0

Answered
Multiple faces merging into a single face when using alphaShape()
I don't think you need polyshape here. Because the shape is always convex, all facets are boundary facets and the facet matrix c...

2 Tage ago | 0

Answered
delete zeros in cell array
Using the attached file sortlidx.m, cellarr = {'b','a','a','a','b';0,'c',0,'b',[];0,'a',0,'d',0;'a','a','b',[],[]} map=cellf...

2 Tage ago | 1

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Answered
Finding the value of x for a corresponding known y value for a curve
find(diff(sign(ucn-143))~=0,1) + 1

2 Tage ago | 0

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Answered
How to create a 3D stack using 2D images
Are you sure you need to do that? It seems like a waste of memory to copy the same image 10 times. If you're sure it's what you...

2 Tage ago | 0

Question

TightInset in conjunction with "axis image"
According to the documentation, the TightInset axes property is defined as "the distances between the bounds of the Position pro...

3 Tage ago | 0 answers | 0

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Answered
FSOLVE requires all values returned by functions to be of data type double.
Get rid of syms a b c d e Write your equations in terms of the numeric variables V(i) instead. Do not use syms anywhere.

3 Tage ago | 0

Answered
Writing Minimization Function to Find Multiple Vectors
lsqlin is appropriate for this problem, https://www.mathworks.com/help/optim/ug/lsqlin.html

3 Tage ago | 0

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Answered
MATLAB script to convert the camera calibration outputs into a format directly suitable for learnable triangulation
The intrinsic and extrinsic parameters are contained in the params object output by the calibration, https://www.mathworks.com/...

3 Tage ago | 0

Answered
Frequencies space to time space with Fourier Trasform (FT and IFT)
Simply going to frequencies space and coming back to time space, the audio changes. Why? But what you are doing is not simply g...

3 Tage ago | 0

Answered
Why does fmincon not provide hessian option for sqp algorithm?
The SQP algorithm does not compute the Hessian via finite differences. It does, however, require a positive definite approximati...

3 Tage ago | 0

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Answered
Matlab FFT differs from theory and oscilloscope
Is the oscilloscope computing the FFT, or is it trying to compute a continuous Fourier transform approximation? If the latter, i...

3 Tage ago | 0

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