Community Profile # Bruno Luong

Last seen: Today Active since 2009

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How to know interpolated points in a MATLAB plot?
hl = findobj(gca, '-depth', 1, 'type', 'line'); x=get(hl,'xdata'); y=get(hl,'ydata'); y10 = 10; i = find((y(1:end-1)-y10...

2 hours ago | 0

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...

5 days ago | 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*...

9 days ago | 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(...

9 days ago | 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...

9 days ago | 0

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...

10 days ago | 0

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...

12 days ago | 0

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

12 days ago | 0

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...

12 days ago | 0

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...

14 days ago | 0

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 ...

14 days ago | 0

Question

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...

14 days ago | 2 answers | 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...

18 days ago | 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...

18 days ago | 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...

19 days ago | 0

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...

19 days ago | 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 ...

19 days ago | 0

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, ...

19 days ago | 1

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...

20 days ago | 1

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

23 days ago | 0

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...

24 days ago | 2

Question

What is MCR R2022b Update 5 ?

25 days ago | 2 answers | 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...

25 days ago | 0

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Question

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

26 days ago | 5 answers | 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)); [...

29 days ago | 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...

1 month ago | 0

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