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# Bruno Luong

Last seen: Today Attivo dal 2009

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Risposto
How to know interpolated points in a MATLAB plot?
% Dummy example of some curve that cross the horizontal line y=10 x = cumsum([0 rand(1,40)]); y = 12*sin(x); plot(x,y,'.-'); ...

1 giorno fa | 1

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minimum value optimization of matrix with constraints
Straighforward implementation, it seems more reliable than Matt's square-root parametrization. The square-root makes the gradie...

6 giorni fa | 0

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The most efficient way to calculate multiplication and summation of two large matrices
It is just a scaling of matrix multiplication, if you haven't recorgnize it A=rand(300,1000); B=rand(300,1000); tic C1=(A*...

10 giorni fa | 1

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Create random symmetric matrix with given cond number to pass it to pcg
n=10; % size of the system condtarget = 1000; % generate ransom spd matrix [Q,~]=qr(randn(n)); r = rand(n,1); r = (r-min(...

10 giorni fa | 0

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How to get a smooth plot by filtering the sudden variation of the data?
It recovers a big tail part of the signal. Hard to guess what should be the signal at the begining. A=readmatrix('https://www.m...

10 giorni fa | 0

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FFT analysis with window of vibration during milling
I don't see the need of calling sgolayfilt. It is just a linear filter so it is equivalent to scale down the signal in frequency...

11 giorni fa | 0

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natural cubic spline interpolation of y-values: how to get derivative of the spline wrt the y-values?
The derivative f wrt to y_i is the spline interpolate b_i := (0,0,...,1,0...) where 1 is at ith position, since the spline is li...

13 giorni fa | 0

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natural cubic spline interpolation of y-values: how to get derivative of the spline wrt the y-values?

13 giorni fa | 0

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How to use isoutlier based in a part of the data?
Not sure, you are not better to describe what you want than most people; what you cann outlier seems to be point that violate th...

13 giorni fa | 0

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Modified Akima Interpolation process
Just look at the refernce provided in the doc page A New Method of Interpolation and Smooth Curve Fitting Based on Local Proced...

15 giorni fa | 0

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How to get around sparse row deletion for least squares calculation
I'm nit sure why you formalize as block sparse, since it is like solving d independent linear systems of the same size, and can ...

15 giorni fa | 0

Domanda

factorization of Multivariate polynomial
Hello, I want to factorize a multivariate polynomial in a complex field. I just don't understand why the result of this simple p...

15 giorni fa | 2 risposte | 0

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what is a reasonable step tolerance for optimization algorithms if parameters are in the range [0,1]?
Your question is not clear enough. the official doc explains how it eaxctly works https://www.mathworks.com/help/optim/ug/toler...

19 giorni fa | 0

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Matrix multiplication gives different result than manual dot products with each column
"Does anyone know why these two expressions don't give the same answer? " Why should they? The algorithm can perform diffrent s...

19 giorni fa | 0

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Why do I see a drop in the last datapoint (Nyquist frequency) of the spectra derived from pwelch?
No I beg to differ the answers that have given to you. The reason is the convention of onesided spectrum. In the code computepsd...

20 giorni fa | 0

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Why the function like (1 - cosd(x)) / cosd(x) doesn't create an vector and can't plot?
Change / to ./, the "/" is matrix left-division and does something you won't expect for vectors x=-25:0.1:25; %Grad in Bogenma...

20 giorni fa | 0

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Failure to load structures into an array through a loop
I copy my answer fromthis thread Usage is typically like this: cellresult = cell(1,n) for i=1:n % do something first ...

20 giorni fa | 0

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Finding two similar Matrix in a whole set
If you have great number of matrices (like 1000 or more) reduce the number of comparisons by computing for each matrix the min, ...

20 giorni fa | 1

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access matlab figures by opening them with a mouse while a matlab terminal application is still running
Here is one way of calling dbcont to exit debug mode without user typing it this FEX keyboard ... wait until user do his/her s...

21 giorni fa | 1

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How can i transform rad/s to hertz for graph?
omega = 2*pi*f with unit omega [rad/s] f [1/s]

24 giorni fa | 0

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How do I uninstall an older version of MATLAB after I have installed a newer version on my Mac OSX?
No don't disactivate MATLAB, just uninstall 2019b. Activation is common for all installed versions. Many versions can be inst...

25 giorni fa | 2

Domanda

What is MCR R2022b Update 5 ?

26 giorni fa | 2 risposte | 0

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R2022B Update4 is not offered
The online update for R2022b Update 4 is NOT offered by TMW. Workaround : do the offline installation. Risk: you need to unin...

26 giorni fa | 0

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Domanda

R2022B Update4 is not offered
Is it just me or the update 4 is not offered via the menu Help => Check for Updates I'm using Update 3

27 giorni fa | 5 risposte | 0

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Finding the length of the longest continuous streak of a same number for each row of a matrix
p = 3; q = 10; r = 2; A = sort(randi(10,p,q,r,'uint16'),2) B = reshape(permute(A,[2 1 3]),q,[]); t = true(1,width(B)); [...

circa un mese fa | 1

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Is this a mistake in documentation or my misunderstanding of FFT?
"Single sided Amplitude spectrum from Double sided spectrum it is only the DC component to be excluded from multiplying by 2" N...

circa un mese fa | 0

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How to encrypt compilation files for standalone?
The MATLAB source files are already encrypted (with you compile with MATLAB compiler, MCC)

circa 2 mesi fa | 1

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movavg with custom type and weights
movavg requires first array is a column vector or matrix A = 1:5; B = [0.5 0.5]; movavg(A(:), "custom", B) % or reshape back...

circa 2 mesi fa | 2