Bruno Luong

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1.676 total contributions since 2009

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Submitted

FFT-based convolution
Discrete convolution using FFT method

3 días ago | 27 downloads |

Answered
How to generate random uint64 values
maxval = int64(2^60); n = 100; twop32 = 2^32; q = double(maxval/twop32); hi = floor(q*rand(1,n)); himax = floor(q); lom...

3 días ago | 0

Answered
How to generate random uint64 values
I can't see why you are reluctant to generate 2 x 4 bytes r = typecast(randi(intmax('uint32'),2*100,1,'uint32'),'uint64')

5 días ago | 1

Answered
Graph Laplacian and adjacency matrix
Not sure what data format you have, but for graph % TMW example s = [1 2 2 3 3 3 4 5 5 5 8 8 9]; t = [2 3 4 1 4 5 5 3 6 7 9 1...

6 días ago | 0

Submitted

find_idx
Fractional binning

9 días ago | 4 downloads |

Answered
Best practices to use Matlab assert
No C debug mode slows every statement down. ASSERT costs the overhead of checking whatever you instruct MATLAB to check. It ma...

17 días ago | 0

Answered
Program to generate permutations in a certain order
clear X X{1}=[1 1 0 1]; X{2}=[1 0 1 0]; X{3}=[1 0 1 1]; X{4}=[1 1 1 0]; X{5}=[0 1 0 1]; X{6}=[0 0 0 1]; n=length(X); P...

24 días ago | 1

Answered
Equivalent of c++'s NULL or python' s None in MATLAB
If you use recent MATLAB you can use also missing and ismissing

27 días ago | 0

Question

How to change number precision with writestruct
The number of significant digits of writestruct is quite limited, as showed by this example s=struct('pi',pi); writestruct(s,...

alrededor de 1 mes ago | 1 answer | 0

1

answer

Answered
Replace nested loops with a matrix
i=2:nhx-1; j=2:nhy-1; U(i,j)= U(i,j)-dt*(Pc(i+1,j)-Pc(i-1,j))/(2*hx);

alrededor de 1 mes ago | 1

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Answered
Get indices of all rows containing a value - repeated or not
[c,~,J] = unique(sort(connections,2),'rows'); [i,~,I] = unique(c); [~,j] = ismember(i, id); xy = [x(j) y(j)]; I = reshape(I,...

alrededor de 1 mes ago | 0

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Answered
Is there a way to vectorise this vector/matrix product?
G = real(dot(W,R*W,1)).';

alrededor de 1 mes ago | 0

Answered
Relative Ranking of position in an array
I10=[1 2 1 1 1 2 1 1 2 2 1 3 6 3 1 3 3 1 4 3 4 3 2 3 4 2 3 3 4 2 7 4 6 2 5 4 5 5 5 5 6 7 5 4 5 8 8 6 4 5 4 6 6 7 9 7 7 2 7...

alrededor de 1 mes ago | 0

Answered
Optimize repeated permutation of a large vector
s = [1 2 3 4 5 6 7 8]; n=[4 3 1]; c=cumsum([0 n]); p=2:length(s)+1; p(c(2:end))=c(1:end-1)+1; s(p)

alrededor de 1 mes ago | 0

Answered
Error using fwrite : Cannot write value: sparse arrays are unsupported.
[i,j,v] = find(S); then save i,j,v with fwrite

alrededor de 1 mes ago | 0

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Answered
Optimize repeated permutation of a large vector
s = [1 2 3 4 5 6 7 8]; i=1:length(s); n=[4 3 1]; c=cumsum([1 n]); b=cumsum(ismember(i,c)); p=mod(i+1-c(b),n(b))+c(b) s(p...

alrededor de 1 mes ago | 0

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Answered
find the position of all non-zero minimum values in each column of a matrix
a = [2 0 3;1 2 5;0 0 0;1 3 3;0 0 6;0 2 7;1 0 0] b=a; b(b==0)=NaN; [r,c]=find(b==min(b,[],1)); rmin=accumarray(c(:),r(:),[siz...

alrededor de 1 mes ago | 1

Answered
Turn logical matrix into string vector
Assuming idx has one 1 per row idx = logical([0 1 0; 0 0 1; 1 0 0; 1 0 0; 0 1 0]); vec = ["A","B","C"]; [r,c]=find(idx); r...

alrededor de 2 meses ago | 1

Answered
Symetric matrix power optimization
Youeu can edit MATLAB function mpower.m and try to the basic calculation (line 76 in my case) D = D*D; % I assume p is integer...

alrededor de 2 meses ago | 0

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Answered
How can I avoid loop for code optimization?
Use MultipleQR FEX (C compiler for MEX build is required, unless for Windows platform) y = linspace(1,10,1000); Y = reshape(...

alrededor de 2 meses ago | 1

Answered
random number of two random varibles.
If K is the (2 x 2) covariariance matrix of (w,T) and mu (2 x 1) is the mean of (w,T), you can generate them like this n = 100...

alrededor de 2 meses ago | 0

Answered
How to avoid a negative solution with fmincon, including an external equation?
The condition f2 = - 2*x1 - 10*x2 + 30 >= 0 is equivalen to 2*x1 + 10*x2 + 0*f1 <= 30. So set A = [2 10 0] b = 30 If you ...

alrededor de 2 meses ago | 0

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Answered
How can I optimize coefficients of a polynomial using fmincon?
"The overall goal is to minimize the length of the cost function " The overall length is L = integral sqrt(dx/dt^2+dy/dt^2+dy/...

alrededor de 2 meses ago | 0

Answered
Is it possible to vectorize this?
NOTE the order of most is sorted with this algorithm: A = [1 2 0 3 4 6; 9 3 4 0 9 5; 4 3 0 5 6 7; 3 7 7 3 0 0...

alrededor de 2 meses ago | 2

Answered
Diagonal of non-square matrix
n = 8; A = spdiags([2 3 4]+zeros(n,1),0:2,n,n+2); A = full(A) % if prefered

alrededor de 2 meses ago | 1

Answered
Randomly splitting of a number in a sum format.
This code will generate "uniform" partition distribution, in the sense that all possible partition has equal probability: n = 1...

alrededor de 2 meses ago | 1

Answered
Will codegen accelerate sub-functions?
Yes coder translates the sub-functions to C as well.

alrededor de 2 meses ago | 0

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Answered
Randomly splitting of a number in a sum format.
n = 10; for j=1:10 r = n; i = 1; clear s while r > 0 s(i) = ceil(r*rand); r = r-s(i); ...

alrededor de 2 meses ago | 0

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Answered
mldivide algorithm for an underdetermined system of equations
The outline of "\" goes as following: % Test data A=randi(10,3,2)*randi(10,2,5) b=randi(10,3,1) [Q, R, P] = qr(A,'vector')...

alrededor de 2 meses ago | 2

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Answered
Function to create struct with parameters
s = buildparams() function s = buildparams() a = 1; b = 2; s = gathervars(); end function s = gathervars() vars = eva...

alrededor de 2 meses ago | 0