Answered
How to customize arrow of directed graph (digraph)
Since R2018b, there is a property ArrowPosition which allows the arrowhead to move around along the edge. There is no way of ch...

7 years ago | 1

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Answered
how to plot graph without intersection?
It sounds like you are looking for functionality related to planar graphs. MATLAB does not have any methods specific to this, bu...

7 years ago | 0

Answered
How to work with quite large matrices?
The matrices A\B and A\C are very likely to be dense, even if A, B, C are sparse matrices. Since these are of size 400'000, no m...

7 years ago | 2

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What is the best method to solve large linear system equation (Ax=b) (A:million~ by million~)
You can try one of the Iterative Methods and Preconditioners.

7 years ago | 0

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Answered
How many arithmetic operations does matlab require to determine the Schur decomposition?
The second step in computing the Schur decomposition is the QR algorithm, not the QR decomposition (unfortunately the names are ...

7 years ago | 0

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Answered
Get non-zero eigenvalues and eigenvectors
You could just remove the zero eigenvalues after computing them: >> X = [1 1; 1 1] X = 1 1 1 1 >> [V,l] =...

7 years ago | 0

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How I can construct Auxiliary matrix in graph for network topology to calculate shortest path between nodes has altitude and latitude ?
Have you looked at the graph and digraph classes in MATLAB (<https://www.mathworks.com/help/matlab/graph-and-network-algorithms....

7 years ago | 0

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Is it possible to vectorize this?
There is no general way to vectorize this. If the starts and ends vector define intervals that are not overlapping, and that cov...

7 years ago | 0

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Answered
Which algorithm does MATLAB eig() use to diagonalize a complex symmetric matrix?
EIG uses LAPACK functions for all cases. If there is a special case treatment for complex symmetric, I'm not aware of this. U...

7 years ago | 1

Answered
Why I got different condition numbers for a simply matrix by two ways in Matlab?
The matrix H is not symmetric. The ratio of largest eigenvalue to smallest eigenvalue for the condition number is only true for ...

7 years ago | 2

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Answered
Eigs Function on Function Handle Not Converged
Hi Sam, The most likely reason for the convergence problems is that the eigenvalues are close together (or even multiples). T...

7 years ago | 1

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Answered
'Unexpected output' error using SVDS with function handle
Maybe the problem is that you use both |x| and |X| in the definition of the anonymous function? A matrix |X| in your workspace w...

7 years ago | 0

Answered
Any alternates function to replace "eig"
The command eig(A,eye(15),'qz'); solves the eigenvalue problem A*x = lambda*x, but makes EIG treat it as the generalized...

7 years ago | 0

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Matrix similarity transformations introduce small imaginary eigenvalue components
If you know the matrix A is supposed to be symmetric, I'd say symmetrize A, and then symmetrize B again, because |Q*A*Q'| will i...

7 years ago | 0

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Answered
How can I do a real asymmetric eigen-decomposition in Matlab
Unfortunately, MATLAB doesn't have a function that does this, and I'm not aware of any existing implementations. To implement...

7 years ago | 1

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Answered
What should be used to diagonalise a complex sparse matrix instead of 'eig'?
If converting the sparse matrix into a dense matrix is possible, that seems like the best thing to do. How do you measure that t...

7 years ago | 0

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Answered
What is the complexity of Matlab's implementation of SVD?
The computational complexity of svd is O(max(m, n) * min(m, n)^2). If the 'econ' flag is not used and all three matrices are ret...

7 years ago | 1

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Answered
Eigenvectors are not orthogonal for some skew-symmetric matrices, why?
Since, as Lorenzo points out in a comment above, |1i*A| is hermitian, you could apply |eig| to that matrix: >> [U, D] = eig...

7 years ago | 0

Answered
L2 norm or Frobenius norm?
The L2-norm of a matrix, |||A|||_2, ( |norm(A, 2)| in MATLAB) is an *operator norm*, which is computed as |max(svd(A))|. For ...

7 years ago | 6

Answered
how to build many sparse matrices
The |sparse| function will often be faster if the second input, |col|, is sorted in ascending order. If you can cheaply construc...

7 years ago | 0

Answered
Formulating objective function & constrain such that the eigenvalue is always positive
Hi Hammed, Your problem looks like a smooth nonlinear optimization problem: I believe the smallest eigenvalue of a linear com...

7 years ago | 1

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Answered
Specify a tolerance for backslash operation or linsolve while A is non-square? (QR solve)
Hi Sam, If you compute |A\B| for two large, sparse matrices (as you mention in your comment to John), the result will typical...

7 years ago | 2

Answered
eigen value problem for sparse matrices
There aren't any practical algorithms for computing eigenvalues one by one. You can compute a subset of eigenvalues around a giv...

7 years ago | 0

7 years ago | 0

Answered
eigen value problem for sparse matrices
The problem is that the eigenvectors of a sparse matrix are dense (in all practically relevant cases), so to store them would re...

7 years ago | 1

Answered
Out of memory issue although there is more RAM space than matlab requires
Hi Oguzhan, As I remember from your <https://www.mathworks.com/matlabcentral/answers/414832-singular-value-decomposition-of-a...

7 years ago | 1

Answered
Get in Order respond when using "eig" command
To sort the eigenvalues to be increasing in magnitude, use the following: [U, d] = eig(k, m, 'vector'); [d, ind] = sort(...

7 years ago | 1

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Answered
Singular Value Decomposition of a Large XYZ file
The way I thought of it was to use x and z as the 2d grid on which to interpolate, and y as the function value. Something like t...

7 years ago | 0

Answered
eigs does not return the eigenvalues closest to shift sigma
Hi Olivier, I'm not sure I know much more to try out. Note that EIGS is doing Y = (A-SIGMA*I)\X based on the LU factorization...

7 years ago | 0

Answered
Singular Value Decomposition of a Large XYZ file
First thing that occurs to me would be to interpolate the xyz data to lie on a rectangular grid in the x-z plane, and to then ap...

7 years ago | 0

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