Answered
Eigenvalues and Eigenvector computation on extremely bad conditioned matrices
If the matrix P has rank 120 and its size is 160, you should expect 40 eigenvalues to be Inf - this is how singularities in the ...

ungefär ett år ago | 0

Answered
QR factorization of a low rank matrix
Let's start with computing a rank-2 approximation of a large matrix. In general, this would be done using the SVD, but if you kn...

ungefär ett år ago | 0

Answered
Can additional information be added to the directed graph plotting node 'tooltip'?
Yes, you can do this using the dataTipTextRow function: nodeNames = {'Node A', 'Node B', 'Node C', 'Node D', 'Node E', 'Node F'...

ungefär ett år ago | 0

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Answered
computational complexity of svds
There is a recent function (introduced R2020b) called svdsketch, which is using randomized linear algebra. We recommend this for...

mer än ett år ago | 0

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Write Hamiltonian using kron function
For a 6-dimensional Kronecker product, you would want to take Sz = [1 0; 0 -1]; I = [1 0; 0 1]; and apply the Kronecker produ...

mer än ett år ago | 0

Answered
Algorithm for edge connectivity of a digraph?
There is no direct method in MATLAB for computing the edge connectivity. Based on the Wikipedia page, you should be able to comp...

mer än ett år ago | 0

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Answered
Get coordinates of 3-D force-directed graph plot without plotting?
There isn't currently such a function available. For the example above, nearly all the time is being spent in computing the coo...

mer än ett år ago | 0

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Answered
Obtain eigs from matrix and partially known eigenvector
Hi Jennifer, You are right that matrix P here is a block-diagonal matrix with three blocks: [A 0 0; 0 B 0 0 0 C] And for su...

mer än ett år ago | 1

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Answered
finding degree and neighbor of each vertex in a subgraph H but indexing according to original graph
I think the easiest will be to build on what you started by giving the nodes in graph G names which are just the string version ...

mer än ett år ago | 0

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Change of parameters of Gates in quantumCircuit does not take effect
This is a bug, thank you for reporting it. As a workaround while waiting for this to be addressed, pleaseconstruct a new gate in...

mer än ett år ago | 2

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Answered
how to find neighbors/degree of hyperedges of a uniform hypergraph?
MATLAB doesn't support hypergraphs, but often a specific problem can be solved with just a graph or multigraph, by interpreting ...

mer än ett år ago | 0

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Answered
LU decomposition algorithm change
As you point out, this kind of difference in result is to be expected and is well withing expected round-off behavior. Another ...

mer än ett år ago | 1

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How can I plot a multilayer graph (2 layer) starting from adjacency matrices?
Here's an example of how to do this (using just some random data, since I don't have the matrices you mention above). % Choose ...

mer än ett år ago | 1

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Answered
How to create a random graph that is connected?
If an undirected graph is connected, it must contain at least one path that visits each node at least once. You could construct...

mer än ett år ago | 0

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I have a question about the distributed computing of the eig function.
EIG for distributed arrays calls into the ScaLAPACK library - the references given by ScaLAPACK documentation would be the best ...

mer än ett år ago | 1

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non linear eigen value problem
This isn't the standard definition of a nonlinear eigenvalue problem, where you would have only one scalar lambda. Am I underst...

mer än ett år ago | 0

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Issues with the normalisation of mode shapes?
eig(A, B) normalizes the eigenvectors in the B-mass norm, but only if it recognizes the input as a symmetric problem (A is symme...

nästan 2 år ago | 0

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Answered
Proof of relation between the generalized singular values of gsvd(A,B) and gsvd(B,A)
The background for this is the 5-output form of the GSVD: [U,V,X,C,S] = gsvd(A,B) returns unitary matrices U and V, a (usually)...

nästan 2 år ago | 0

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Update a sparse matrix efficiently
The fastest way to construct a sparse matrix will be when the inputs are sorted, first by columns and then by rows. You can veri...

nästan 2 år ago | 1

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Given a big square matrix and some eigenvalues, how to find the corresponding eigenvectors?
I wouldn't expect a 3072-by-3072 matrix to be a problem on the machine you describe. Could you try to run the following on your ...

nästan 2 år ago | 0

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Answered
new interface for QR decomposition in Matlab 2022a
Yes, we made this change for R2022a. I'm sorry this has caused problems for you, @Klaus Diepold, could you share how you had bee...

nästan 2 år ago | 1

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how to find eigenvalues using the determinant ?
The determinant should only be used explicitly to solve an eigenvalue problem for symbolic calculation (for example, when you so...

ungefär 2 år ago | 2

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Answered
GUI crashes when using eigs with a nonzero shift on a large generalised eigenvalue problem.
Ideally this shouldn't crash, but produce an out-of-memory error. However, for example on Linux there is the "out-of-memory kill...

ungefär 2 år ago | 0

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Answered
GPU speed up for pcg() is disappointing
It looks like you can simply replace your current call to pcg with x = pcg(A, b, tol, 5000, @(y) L\y, @(y)L'\y); as the error ...

ungefär 2 år ago | 0

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What is matlab doing under the hood when I solve this generalized eigenvalue problem?
You can use the Display option to get some more information on what's going on inside of eigs. load matrices.mat [V,D] = eigs(...

ungefär 2 år ago | 1

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Answered
Trapz error in calculating 2D integrals: ORDER contains an invalid permutation index
Replace the line I = cumtrapz(y,cumtrapz(x,MBerry(keySet),2)); with I = cumtrapz(y,cumtrapz(x,MBerry(keySet),2), 1); Here'...

mer än 2 år ago | 0

Answered
`svd` sometimes blows up - how to fix it?
In short, the problem is that pinv_modified is based on a misunderstanding of the workaround here. The idea is to check if SVD f...

mer än 2 år ago | 1

Answered
Calculating node coordinates for a graph without plot command
Unfortunately there isn't a way to get these coordinates without plotting. I have added your request for such a function to our ...

mer än 2 år ago | 1

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Answered
'MarkerEdgeColor' for Graph/Digraph Nodes
Yes, MATLAB's graph and digraph plots only have one NodeColor property which applies to both the marker's FaceColor and EdgeColo...

mer än 2 år ago | 0

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How to convert a graph / edges list into a shapefile (.shp) ?
There isn't a direct way to do this with a graph object. The mapping toolbox has a shapewrite function which produces a .shp fil...

mer än 2 år ago | 0