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Christine Tobler


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MathWorks

216 2015 이후 총 참여 횟수

Professional Interests: numerical linear algebra, graph algorithms

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Sort eigenvectors matrix.
Take a look at rsf2csf. For a block-diagonal matrix with 1-by-1 and 2-by-2 blocks, it computes a diagonal eigenvalue matrix and ...

5일 전 | 1

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Eigenvectors of an SPD matrix being saved as complex doubles
EIG does not recognize the input matrix as symmetric because it's not exactly symmetric. If you compute A = Y'*Mh*Y norm(A - A...

8일 전 | 0

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Given a matrix A^n. Comparing normal multiplication versus Diagonalization. I expect the former to be faster but its not in my case
A^2 is just one matrix multiplication, A*A, which is much faster to do directly than the call to EIG. For larger n, A^n isn't ...

25일 전 | 0

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how to random initialize svd function in matlab??
The linear algebra functions in MATLAB are run-to-run reproducible, meaning if you call them twice with the exact same input, yo...

26일 전 | 1

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EigenValues of a Vibrating system
Usually for finite element problems, the stiffness matrix is passed in as the first input, and the mass matrix as the second inp...

28일 전 | 0

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issues with Cholesky decomposition
This can happen if your matrix is close to symmetric positive semi-definite (meaning the smallest eigenvalue is around machine e...

29일 전 | 0

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Can I preserve adding order when calling graph/addedge?
The edges in a graph are always presented in the same order (sort first by source node, secondarily be target node). You can mai...

약 1달 전 | 1

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Display only one eigenvalue of symbolic matrix
The eigs function is not supported for symbolic values, as it is specifically based on getting a good approximation based on an ...

약 1달 전 | 0

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how to do forward neighbor discovery in un-directed graph?
If I understand correctly, you want to find all nodes that are direct neighbors of n1, then all nodes that connect to n1 through...

약 2달 전 | 0

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Using eigs with singular matrix
The 'smallestabs' option in eigs depends on solving several linear systems with the matrix A that's being passed in. If A is sin...

약 2달 전 | 0

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Change the alignment and font size of edgelabels
The edge labels provided with the plot of a graph can't be modified in terms of their alignment. However, you can add standard t...

약 2달 전 | 0

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a question for defining Custom Deep Learning Layer
You can use the svd in a custom layer, however, if the SVD is used in the forward method of a custom layer, this will likely req...

약 2달 전 | 0

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Control edge alpha via edge weights to visualize a dynamic network
You can set the LineStyle to be 'none' for edges that should not be displayed: >> g = digraph([3 1 2], [2 3 1], [0 0.5 1]); >>...

2달 전 | 1

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how to create a symmetric Toeplitz matrix with bounds on eigenvalues?
You can use the MATLAB function toeplitz with one input argument (two-input returns a non-symmetric Toeplitz matrix).

2달 전 | 0

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Interpolation for n-dimensional array data
I don't think interpn would work very well for you: The U, S and V matrices returned by SVD are not linearly dependent on the in...

2달 전 | 1

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eigs gives wrong eigenvalues
Edit: Please see the comment below, the first answer I gave here was going in the wrong direction. Thank you for the detailed d...

2달 전 | 2

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How can I solve linear equation system in parallel?
As John says, if you are using decomposition on one computer with several cores, the solver used already will use those cores if...

3달 전 | 1

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Why Power of Matrix with decimal values gives really big numbers?
For a Markov Chain, you need the sum of each row to be 1 (as this represents the probability to transition to any state), and ev...

3달 전 | 0

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Which Right Eigenvector to report?
The left and right eigenvectors are matched one-by-one. For example, for [V, D, W] = eig(A), the eigenvalue D(k, k) corresponds ...

3달 전 | 0

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eigs for generalized eigenvalue problem ( [V,D] = eigs(A,B) ) with spars matrix
A bug was introduced in R2017b in eigs for matrices with exact zero eigenvalues. This bug has been fixed in R2019a, the fix appl...

3달 전 | 1

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Error using eig Input matrix contains NaN or Inf from images
The variable covariance_matrix contains non-finite values (either Inf meaning infinity, returned for example from 1/0, or NaN me...

3달 전 | 0

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Why are eigenvector matrices computed by matlab not idempotent
Hi Marco, You seem to be confusing two terms: A matrix M is idempotent if ; it's orthogonal if , which is what you are testing ...

4달 전 | 2

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Warning: Matrix is close to singular or badly scaled. Results may be inaccurate. RCOND = 7.252760e-17.
As lambda approaches an eigenvalue of A (which is the goal of your algorithm), the matrix A - lambda*eye(size(A)) becomes close ...

4달 전 | 1

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How to compute efficiently A^(-1)*(1-exp(-A*h))?
For most sparse matrices expm(A) will be dense, so that should be expected to be expensive with a 1e4-by-1e4 matrix. If you are ...

4달 전 | 0

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How to add svd(singular value decomposition) in a custom layer
When dlarray supports a function, this means, most of all, that it supports automatic differentiation of this function - which f...

4달 전 | 0

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How to add svd(singular value decomposition) in a custom layer
Yes, this is because SVD is not supported for dlarray. For its first release in R2019b, dlarray supports about 80 basic methods,...

4달 전 | 0

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Open just some Graph Edges in Variable Editor and let the user modify them?
That's tricky: In terms of assignment, if G.Edges(i, :) is assigned to, the graph class interprets this as assigning to all elem...

4달 전 | 0

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how get graph?
Since MATLAB R2015b, there are Graph and Network Algorithms in MATLAB that will allow you to construct and plot a graph of these...

4달 전 | 0

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Connected graph given adjacency matrix
I realize this is an old question, but since it's still getting visits, I have a small addition. As of R2015b, the new graph and...

4달 전 | 1

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Extract eigenvalues and eigenvectors / Symbolic to numeric / Rayleigh-Ritz Method / Vibro-acoustics
The problem is making i and j into symbolic variables, which leads to the symbolic engine not knowing that these are real intege...

4달 전 | 0

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