Christine Tobler
MathWorks
Followers: 0 Following: 0
Spoken Languages:
English, French, German
Pronouns:
She/her
Professional Interests:
Graph and Network Algorithms, Linear Algebra, Quantum Computing
English, French, German
Pronouns:
She/her
Professional Interests:
Graph and Network Algorithms, Linear Algebra, Quantum Computing
Statistics
All
RANK
99
of 298,922
REPUTATION
1,380
CONTRIBUTIONS
0 Questions
437 Answers
ANSWER ACCEPTANCE
0.00%
VOTES RECEIVED
276
RANK
of 20,661
REPUTATION
N/A
AVERAGE RATING
0.00
CONTRIBUTIONS
0 Files
DOWNLOADS
0
ALL TIME DOWNLOADS
0
CONTRIBUTIONS
0 Posts
CONTRIBUTIONS
0 Public Channels
AVERAGE RATING
CONTRIBUTIONS
0 Highlights
AVERAGE NO. OF LIKES
Feeds
Answered
real power of matrices
I'm not seeing the described behavior: x = [1 0 0; 0 1 0; 2 3 1]; y = mpower(x, 0.5) y*y Can you try to rerun the code?
real power of matrices
I'm not seeing the described behavior: x = [1 0 0; 0 1 0; 2 3 1]; y = mpower(x, 0.5) y*y Can you try to rerun the code?
4 days ago | 0
Answered
How does Matlabs svd() function calculate the value of V?
Hi Caleb, Happy to discuss the svd with you! That being said, as others here have mentioned, svd is a building block and not e...
How does Matlabs svd() function calculate the value of V?
Hi Caleb, Happy to discuss the svd with you! That being said, as others here have mentioned, svd is a building block and not e...
5 days ago | 1
Answered
NaN output only when using three ouput for QR
The 3-output syntax and the 2-output syntax of QR use different implementations, so that's likely the reason you're seeing diffe...
NaN output only when using three ouput for QR
The 3-output syntax and the 2-output syntax of QR use different implementations, so that's likely the reason you're seeing diffe...
2 months ago | 1
Answered
In a (possibly directed) graph, is there a simple way to find all nodes reachable for a given node?
The quickest way to find all nodes reachable from a given node is using the nearest function with Inf as the distance: g = digr...
In a (possibly directed) graph, is there a simple way to find all nodes reachable for a given node?
The quickest way to find all nodes reachable from a given node is using the nearest function with Inf as the distance: g = digr...
2 months ago | 1
Answered
eig() working where eigs() doesn't
The 'largestreal' option can be useful, but this depends on the problem. The iteration inside eigs will naturally find the eigen...
eig() working where eigs() doesn't
The 'largestreal' option can be useful, but this depends on the problem. The iteration inside eigs will naturally find the eigen...
3 months ago | 0
Answered
Should mldivide Return a Solution for Square, Rank-Deficient, but Consistent Set of Linear Equations?
Hi Paul! You can use x = linsolve(A, b, struct('RECT', true)); to use the QR method of mldivide even if A is square. To get ...
Should mldivide Return a Solution for Square, Rank-Deficient, but Consistent Set of Linear Equations?
Hi Paul! You can use x = linsolve(A, b, struct('RECT', true)); to use the QR method of mldivide even if A is square. To get ...
3 months ago | 3
| accepted
Answered
how can improve limitation of input simulation function of quantum circuit.limitation is number of qubits
The limit of 20-30 qubits is what would be expected for a state vector simulation, which requires a vector of length 2^NumQubits...
how can improve limitation of input simulation function of quantum circuit.limitation is number of qubits
The limit of 20-30 qubits is what would be expected for a state vector simulation, which requires a vector of length 2^NumQubits...
5 months ago | 0
Answered
Problem in assigning proper eigevalues in a for-loop
Sorting the returned eigenvalues by their real part (since you are plotting only the real part of the eigenvalues) should help. ...
Problem in assigning proper eigevalues in a for-loop
Sorting the returned eigenvalues by their real part (since you are plotting only the real part of the eigenvalues) should help. ...
5 months ago | 0
| accepted
Answered
polyeig calculating few polynomial eigenvalue
While there is no equivalent to eigs for polyeig, if you just need some eigenvalues, you could step through polyeig.m and get wh...
polyeig calculating few polynomial eigenvalue
While there is no equivalent to eigs for polyeig, if you just need some eigenvalues, you could step through polyeig.m and get wh...
5 months ago | 0
Answered
Numerical search for the singular points of a complex matrix
From your description, it appears you have a nonlinear eigenvalue problem (a matrix A(lambda) where you are looking for a comple...
Numerical search for the singular points of a complex matrix
From your description, it appears you have a nonlinear eigenvalue problem (a matrix A(lambda) where you are looking for a comple...
5 months ago | 0
Answered
Non Linear Eigenvalue problem
Sorry for answering so long after the initial post. One option you could consider for solving a nonlinear eigenvalue problem is ...
Non Linear Eigenvalue problem
Sorry for answering so long after the initial post. One option you could consider for solving a nonlinear eigenvalue problem is ...
5 months ago | 0
Answered
Incorrect evaluation by Composite Quantum Gate
The issue is a typo in your code. Instead of constructing 3 identity gates, your third gate is an X gate: innerUGates = [idGate...
Incorrect evaluation by Composite Quantum Gate
The issue is a typo in your code. Instead of constructing 3 identity gates, your third gate is an X gate: innerUGates = [idGate...
8 months ago | 0
| accepted
Answered
Remove node and reconnect edges in a very large graph
It is usually best to first compute all the edges / nodes to act on, and then modify the graph in one step with all of them: G1...
Remove node and reconnect edges in a very large graph
It is usually best to first compute all the edges / nodes to act on, and then modify the graph in one step with all of them: G1...
9 months ago | 0
Answered
How to find the best solution to make eigs function converge?
It seems that the eigenvalues of H are pure imaginary (I'm seeing real parts of magnitude about 1e-14, and the maximum imaginary...
How to find the best solution to make eigs function converge?
It seems that the eigenvalues of H are pure imaginary (I'm seeing real parts of magnitude about 1e-14, and the maximum imaginary...
10 months ago | 0
Answered
Call to inv() function seems to have (undesired) impact on Thread pool or maxNumCompThreads()
I asked around internally, and there was an issue that looks very similar in R2023b that has been fixed in R2024a. If you have R...
Call to inv() function seems to have (undesired) impact on Thread pool or maxNumCompThreads()
I asked around internally, and there was an issue that looks very similar in R2023b that has been fixed in R2024a. If you have R...
10 months ago | 0
| accepted
Answered
solving linear system with decomposition(A,'qr') and qr(A) produce different results
There are two reasons that the results don't match: 1) When the matrix is not full-rank, the QR-based solver in decomposition o...
solving linear system with decomposition(A,'qr') and qr(A) produce different results
There are two reasons that the results don't match: 1) When the matrix is not full-rank, the QR-based solver in decomposition o...
11 months ago | 1
| accepted
Answered
What is the most computationally efficient factorization of a matrix A?
Your solution is correct. Of the factorizations you know (PA=LU, the Choleski, SVD and the QR factorization), only LU and Chole...
What is the most computationally efficient factorization of a matrix A?
Your solution is correct. Of the factorizations you know (PA=LU, the Choleski, SVD and the QR factorization), only LU and Chole...
12 months ago | 1
Answered
Improving Precision of Eigenvectors with Large Eigenvalues
The linked post is about a symmetric matrix, is this also your case? In that case (if issymmetric returns true for your matrix),...
Improving Precision of Eigenvectors with Large Eigenvalues
The linked post is about a symmetric matrix, is this also your case? In that case (if issymmetric returns true for your matrix),...
12 months ago | 2
| accepted
Answered
Join Subgraphs into a new Graph
Here's a quick example based on a guess at how you would like to merge the graphs: G1 = graph(["A" "B" "C"], ["B" "C" "D"]); G...
Join Subgraphs into a new Graph
Here's a quick example based on a guess at how you would like to merge the graphs: G1 = graph(["A" "B" "C"], ["B" "C" "D"]); G...
12 months ago | 1
| accepted
Answered
how to increase node/edge separation within the layer in the layered graph?
You can access the XData and YData properties of the GraphPlot object returned by plot, to move the nodes further apart. Note i...
how to increase node/edge separation within the layer in the layered graph?
You can access the XData and YData properties of the GraphPlot object returned by plot, to move the nodes further apart. Note i...
1 year ago | 0
Answered
Nonorthogonal eigenvectors for general eigenvalue problem with eig() and eigs()
For simple eigenvalue problem A*x = lambda*x, the eigenvalues are real and the eigenvectors can form an orthogonal basis only if...
Nonorthogonal eigenvectors for general eigenvalue problem with eig() and eigs()
For simple eigenvalue problem A*x = lambda*x, the eigenvalues are real and the eigenvectors can form an orthogonal basis only if...
1 year ago | 0
| accepted
Answered
Name for adjancy-to-graph algorithm?
The graph object in MATLAB uses an internal data format that is very similar to a sparse adjacency matrix, so the construction o...
Name for adjancy-to-graph algorithm?
The graph object in MATLAB uses an internal data format that is very similar to a sparse adjacency matrix, so the construction o...
1 year ago | 0
| accepted
Answered
Convert an image to a graph object
From a graph theory perspective (others may have better ideas from the image processing side), I would start by making a graph o...
Convert an image to a graph object
From a graph theory perspective (others may have better ideas from the image processing side), I would start by making a graph o...
1 year ago | 0
Answered
eigs with complex hermitian matrix, should I set opts.issym to 1?
This only matters if you pass in a function handle - if you pass in a matrix, EIGS detects if it's hermitian (real or complex) d...
eigs with complex hermitian matrix, should I set opts.issym to 1?
This only matters if you pass in a function handle - if you pass in a matrix, EIGS detects if it's hermitian (real or complex) d...
1 year ago | 0
Answered
Cyclebasis function for graphs not working
Yes, cyclebasis returns a fundamental cycle basis, but not necessarily the one with the shortest cycle lengths. See the document...
Cyclebasis function for graphs not working
Yes, cyclebasis returns a fundamental cycle basis, but not necessarily the one with the shortest cycle lengths. See the document...
1 year ago | 1
| accepted
Answered
SVD computation time question
I'm not sure what causes the sharp change between iterations - I can reproduce roughly similar timings when I call svd with 3 ou...
SVD computation time question
I'm not sure what causes the sharp change between iterations - I can reproduce roughly similar timings when I call svd with 3 ou...
1 year ago | 1
| accepted
Answered
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...
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...
1 year ago | 0
Answered
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...
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...
1 year ago | 2
| accepted
Answered
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...
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...
1 year ago | 0
Answered
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...
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...
1 year ago | 0
