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# Christine Tobler

### MathWorks

Last seen: 5 Tage vor Aktiv seit 2015

Followers: 0   Following: 0

Spoken Languages:
English, French, German
Pronouns:
She/her
Professional Interests:
Graph and Network Algorithms, Linear Algebra, Quantum Computing, Automatic Differentiation

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Beantwortet
What is the residual defined in eigs?
The issue is likely that eigs doesn't use the residual as you describe it: The iterative algorithm used inside of eigs when comp...

17 Tage vor | 0

Beantwortet
LU decomposition with 5 output arguments
As Matt says, the simplest is likely to just use decomposition object. In terms of how to solve a linear system, the doc page g...

29 Tage vor | 2

| akzeptiert

Beantwortet
Proper Installation of Tensor Toolbox
Find the path the folder that defines the class you want to use. My guess is for Tucker this will be the ttensor class (but it's...

etwa ein Monat vor | 0

Beantwortet
Computing eigenvalues and eigenvectors of two symbolic matrices
eig does not support the two-input syntax for symbolic. For the call eig(B, A), if A is invertible you can instead solve eig(A\B...

etwa ein Monat vor | 0

Beantwortet
Stability analysis of a time dependent Lyapunov equation
The tensorprod function doesn't do what you are looking for here, that would be kron (short for Kronecker product). It also see...

etwa 2 Monate vor | 0

Beantwortet
getting warning while using eigs on the matrices obtained from freefem++
If modifying the input sigma doesn't help, it's likely that for your call eigs(A, B, sigma, ...) the matrices are such that A - ...

2 Monate vor | 0

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Beantwortet
Trying to construct a filtered graph using pmfg function that uses the (MATLAB-BGL) library in MacBook.
The problem seems to be with the MatlabBGL FileExchange package and specifically with the .mex files that are being provided the...

2 Monate vor | 0

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Beantwortet
Can I get all of the shortest paths between all pairs of nodes in a Directed Graph in one function call
Using shortestpathtree in a loop over the starting node is the way to go. You can change the data format of the first output by ...

3 Monate vor | 1

Beantwortet
Inconsistency between Matlab eig() function and Matlab generated C code eig() function
For code generation, the eig function doesn't have as many special-case treatments as the eig function in regular MATLAB. This m...

3 Monate vor | 2

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Beantwortet
How to control the curvature of each edge when drawing graph object?
The curvature of the edges in this plot aren't controllable. You could turn off the edges from the graph plot, and use the plot ...

3 Monate vor | 1

Beantwortet
eigs function works slowly
A possible issue is that "largestreal" option works less towards the strengths of the EIGS algorithm than the default "largestab...

4 Monate vor | 0

Beantwortet
Why is my parfor loop running slower than a regular for loop
The problem is likely that the cost of each iteration is still too small to warrant the start-up time of the parfor loop. You c...

4 Monate vor | 0

Beantwortet
Quick method in solving symmetric linear equation
You can definitely use iterative methods such as pcg. The success of this usually depends on how well-conditioned your matrix is...

6 Monate vor | 1

Beantwortet
doc QR decomposition error
Hi, As you can see here, R is an m by n matrix and Q is an m by m matrix in the default behavior of the qr function: A = randn...

6 Monate vor | 0

Beantwortet
Replacing old version graphshortestpath with new shortestpath function
You can replace [ dist,path{1} ] = graphshortestpath( adjMatrix, 1, numel(newImg(:))); with [ path{1}, dist ] = shortestpath(...

6 Monate vor | 0

Beantwortet
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 ...

6 Monate vor | 0

Beantwortet
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...

7 Monate vor | 0

Beantwortet
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'...

8 Monate vor | 0

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

8 Monate vor | 0

Beantwortet
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...

8 Monate vor | 0

Beantwortet
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...

9 Monate vor | 0

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Beantwortet
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...

9 Monate vor | 0

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Beantwortet
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...

10 Monate vor | 1

| akzeptiert

Beantwortet
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 ...

10 Monate vor | 0

Beantwortet
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...

10 Monate vor | 2

| akzeptiert

Beantwortet
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 ...

10 Monate vor | 0

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Beantwortet
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 ...

11 Monate vor | 1

Beantwortet
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 ...

etwa ein Jahr vor | 1

| akzeptiert

Beantwortet
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...

etwa ein Jahr vor | 0

Beantwortet
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 ...

etwa ein Jahr vor | 1

| akzeptiert