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Bruno Luong


Last seen: Today Active since 2009

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Answered
Finding a propriate function to fit "U" curve
This is the best I come up with using BSFK FEX x=[0.17 0.33 0.83 1.67 2.5 3.33 5]; y=[6.62466 5.58235 4.63169 5.08213 5.4159 5...

18 hours ago | 0

Answered
linprog ignores options, why?
Can you run with exitflag and output [x, fval, exitflag, output] = linprog( c, A, b, [], [], [], [], options ) and share them...

19 hours ago | 1

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Answered
Why does MATLAB differentiate between strings and character array data types?
strings is introduced recently and the behavior is not the same than char array, an historic class. So they create a new class t...

1 day ago | 0

Answered
Supplying gradient for the subset of parameters
May be you could provide the gradient interface for all, but compute the subset derivative analytically and the complement by fi...

2 days ago | 0

Answered
Matrix algebra AxB=C, I want to solve for B
You can't recover the "original" B, whatever it is, your system is underdetermined (much more unknowns - 1826 - than equations -...

2 days ago | 1

Answered
How can I assign zeros to a particular value in an expression
test function test N =4; u = (1:N); v = (N:2*N-2); function ui = getu(i) if i <= 0 | i >= 4 ui = 0; else ui =...

3 days ago | 0

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Answered
How to find x value for a known y in array plot?
* x = linspace(-3,3); Assuming your data are monotonic on the neighborhood of the max y = exp(-x.^2); [maxy, imax] = max(y...

3 days ago | 0

Answered
pause() function is inaccurate
The accuracy is documented. "The accuracy of the pause function is subject to the scheduling resolution of your operating syste...

3 days ago | 1

Answered
Question about the fminsearch Algorithm
fminsearch is an mfile, you can copy it then mofify these lines #196 (R2022a) % Set up a simplex near the initial guess. % PUT...

3 days ago | 0

Answered
How to reduce the usage of "broadcast variables" when using parfor
You can use parallel constant to convert el, el_row1, ds, vmin to constant and reduce the data transfert, if they are not modifi...

3 days ago | 0

Answered
Concatenate arrays of different length inside loop
What's wrong with cell? vox_count_cell = cell(1, length(image_files)); for i = 1:length(image_files) header = spm_vol(ima...

3 days ago | 0

Answered
How do I implement multistart with lsqnonlin in my code?
"it returns the initial value" It indicates that the fit fails, not problem of wrong stating points (converge to local minima)....

3 days ago | 0

Answered
solve equation numerically 1=(1/y)x*exp(x*y)
Numercial solution y = 0.01:0.01:1; x = nan(size(y)); for k=1:length(y) yk = y(k); x(k) = fzero(@(x)x.*exp(x.*yk)-y...

3 days ago | 0

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Answered
How can I find negative factorial ? (-0.5)!
There are actually different ways of extending factorial function, see here http://www.luschny.de/math/factorial/hadamard/Hadam...

4 days ago | 1

Answered
install standalone application on macOs, that was compiled on windows
" According to Matlab, I think it should be possible (https://de.mathworks.com/help/compiler/install-deployed-application.html) ...

4 days ago | 0

Answered
Remove all rows of an array based on a value in a column, and also remove all rows that have the same values as this row in other columns
M = [ 15.88 18.43 15.88 18.43 0 15.88 18.43 33.48 14.99 ...

4 days ago | 0

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Answered
why is acumarray much slower calculating means than sum?
The default behavior of accumarray is sum and it's low-level coded. When you pass user-defined function MATLAB will call the fu...

4 days ago | 2

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Question


reduction variables and evaluation order
This the doc on can read "A reduction variable accumulates a value that depends on all the iterations together, but is independ...

5 days ago | 1 answer | 1

1

answer

Answered
Adding fields to a struct?
[PR1Data.filename] = deal(''); or if you PR1Data is non empty PR1Data(1).filename = '';

5 days ago | 1

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Answered
Faster way to create a matrix of the unique() of each row of a matrix
% Test example A=randi(4,10,5) [m,n] = size(A); As=sort(A,2); b=[true(m,1),diff(As,1,2)>0]; R=repmat((1:m)',1,n); C=cums...

6 days ago | 1

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Answered
How to create 3D matrix with empty cells
cell(3,3,3) % replace 3 with 300 for you I'm still afraid you'll be soon in trouble if you ask such question about easy data cr...

6 days ago | 0

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Answered
Fit coefficients are equal (to starting points) in 3000 different fits
Can you do check whereas they are identical with this command after the loop isequal(Coefficients(:,10),Coefficients(:,2999)) ...

6 days ago | 0

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Answered
How to find the intersection of multiple arrays (or rows of a matrix) in a short code
Put in the cell then use comma list systax: c = {a, b, c, ...}; % or use mat2cell, num2cell depends how you store your 172 vect...

6 days ago | 1

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Answered
2D Interpolation of data
You have scattered data, you should use scatteredInterpolant or similar, not interp2.

6 days ago | 0

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Answered
Load an array instead of a struct with fields
Do this when loading, Container = load('Saving.mat'); Saving = Container.Saving; Check out doc of save ans struct so you won...

6 days ago | 1

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Answered
scatteredInterpolant function is providing too much noise in interpolation
The problem raises from the fact that scatteredInterpolant use Delaunay triangulation, meaning that X and Y are assumed to have ...

6 days ago | 1

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Answered
Without resorting to FEX/MEX, can the overhead of repeated calls to sparse() be avoided with operations on I, J, V directly?
EDIT: Here is the final code. Method used in B2 is the fatest; M = 10000; N = 10000; N_k = 100; A_k = cell(1,N_k); for k=1:...

6 days ago | 0

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Answered
Does intlinprog use cuts during its Branch and Bound Algorithm?
The document CutMaxIterations: Number of passes through all cut generation methods before entering the branch-and-bound phase,...

7 days ago | 0

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Answered
Vectorized way to assign columns/rows of matrix to struct array's field
split = num2cell(matrixToAssign,1); [structArray.field] = deal(split{;});

7 days ago | 0

Answered
What is the best smoothing procedure to calculate differentials for a large number of data points (x,y)?
The Savitzky-Golay filter (moving polynomial fit) is a good filter that preserves decendly the slope. There is a similar thread...

7 days ago | 2

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