Professional Interests: numerical linear algebra, graph algorithms

Answered

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...

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...

1 jour ago | 0

Answered

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,...

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,...

2 jours ago | 0

Answered

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...

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...

13 jours ago | 0

| accepted

Answered

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...

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...

13 jours ago | 0

Answered

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...

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...

13 jours ago | 1

Answered

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...

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...

17 jours ago | 0

Answered

Graph visualization adding white to my nodes. How to solve it?

I'd assume this problem will also happen with other graphics elements. Could you try the following code and let me know if you'r...

Graph visualization adding white to my nodes. How to solve it?

I'd assume this problem will also happen with other graphics elements. Could you try the following code and let me know if you'r...

23 jours ago | 1

| accepted

Answered

Shortest path through node group sets

There is no direct graph-based algorithm to solve this. I would suggest using the optimization toolbox to define this as an opti...

Shortest path through node group sets

There is no direct graph-based algorithm to solve this. I would suggest using the optimization toolbox to define this as an opti...

24 jours ago | 1

| accepted

Answered

Error using 'graph' function in matlab R2019b

Could you try starting a new MATLAB and just enter the following code: >> A = ones(3); >> G = graph(A); If this gives the err...

Error using 'graph' function in matlab R2019b

Could you try starting a new MATLAB and just enter the following code: >> A = ones(3); >> G = graph(A); If this gives the err...

environ un mois ago | 0

| accepted

Answered

how to avoid floating point error and figure out a way to break out of this loop such that it generates correct answer

There has been a lot of research on how to deal with floating-point error in the Lanczos algorithm, see the Wikipedia page for s...

how to avoid floating point error and figure out a way to break out of this loop such that it generates correct answer

There has been a lot of research on how to deal with floating-point error in the Lanczos algorithm, see the Wikipedia page for s...

environ un mois ago | 0

Answered

Why my eigenvalues from (v,d)=eig(k,m) are so close to each other?

Since you mentioned eigenvalues converging at a certain number in the context of FEA analysis: This is usually not the case for ...

Why my eigenvalues from (v,d)=eig(k,m) are so close to each other?

Since you mentioned eigenvalues converging at a certain number in the context of FEA analysis: This is usually not the case for ...

environ un mois ago | 0

Answered

Does the function "ode45" use matrix decomposition?

ODE45 does not use a decomposition or solve a linear system with A. However, ODE15s and ODE23s, which are specialized for "stiff...

Does the function "ode45" use matrix decomposition?

ODE45 does not use a decomposition or solve a linear system with A. However, ODE15s and ODE23s, which are specialized for "stiff...

environ un mois ago | 0

| accepted

Answered

could anyone help me to calculate the euclidean distance for the matrix.

Hi Bruno, I have the same problem where I can't comment on your answer, so adding another answer here. That's a good point - ve...

could anyone help me to calculate the euclidean distance for the matrix.

Hi Bruno, I have the same problem where I can't comment on your answer, so adding another answer here. That's a good point - ve...

2 mois ago | 0

Answered

could anyone help me to calculate the euclidean distance for the matrix.

For MATLAB R2017b or later, you can use the vecnorm function for a simpler construction than the one involving sqrt, sum, and .^...

could anyone help me to calculate the euclidean distance for the matrix.

For MATLAB R2017b or later, you can use the vecnorm function for a simpler construction than the one involving sqrt, sum, and .^...

3 mois ago | 1

Answered

Hi just want to know if someone can maybe help me i have this matrix t want to get the eigenvector but it give me complex values and im pretty sure it must not be complex values for that matrix

A simple way to verify if the returned eigenvalues are correct is to compute both the eigenvalues and the eigenvectors, and to c...

Hi just want to know if someone can maybe help me i have this matrix t want to get the eigenvector but it give me complex values and im pretty sure it must not be complex values for that matrix

A simple way to verify if the returned eigenvalues are correct is to compute both the eigenvalues and the eigenvectors, and to c...

3 mois ago | 1

Answered

How can I solve a sparse linear system efficiently in MATLAB?

Do you need the whole matrix A*inv(B)*A', or do you just need to apply this matrix to a vector (A*inv(B)*A'*x)? In the second ca...

How can I solve a sparse linear system efficiently in MATLAB?

Do you need the whole matrix A*inv(B)*A', or do you just need to apply this matrix to a vector (A*inv(B)*A'*x)? In the second ca...

4 mois ago | 0

Answered

Backslash (\) operator became much slower when updating from 2015b to 2019a

Thank you for these logs. The difference in behavior comes from the following message, saying that we repeat the factorization w...

Backslash (\) operator became much slower when updating from 2015b to 2019a

Thank you for these logs. The difference in behavior comes from the following message, saying that we repeat the factorization w...

5 mois ago | 1

| accepted

Answered

Backslash (\) operator became much slower when updating from 2015b to 2019a

Based on the spy plot, I would be astonished if a different method was selected between the two releases - I think the LU solver...

Backslash (\) operator became much slower when updating from 2015b to 2019a

Based on the spy plot, I would be astonished if a different method was selected between the two releases - I think the LU solver...

5 mois ago | 1

Answered

Backslash error ''Warning: Matrix is singular to working precision."

For more details about what backslash does for sparse matrices, use spparms('spumoni', 1) cnew = Amat \ rhs; This will displa...

Backslash error ''Warning: Matrix is singular to working precision."

For more details about what backslash does for sparse matrices, use spparms('spumoni', 1) cnew = Amat \ rhs; This will displa...

6 mois ago | 1

Answered

SVD freezes in 2018a

This sounds like a bug. It shouldn't be due to memory issues, SVD uses the same amount of memory if the matrix size and the synt...

SVD freezes in 2018a

This sounds like a bug. It shouldn't be due to memory issues, SVD uses the same amount of memory if the matrix size and the synt...

6 mois ago | 0

| accepted

Answered

generalized eigen-problom, complex non-symmetric matrix, how to find orthogonal eigenvectors

There's an easier way to compute both U and W: [U, D, W] = eig(A, B); This will make sure that the eigenvectors U(:, i) and V(...

generalized eigen-problom, complex non-symmetric matrix, how to find orthogonal eigenvectors

There's an easier way to compute both U and W: [U, D, W] = eig(A, B); This will make sure that the eigenvectors U(:, i) and V(...

6 mois ago | 1

Answered

Optimizing a matrix with cplexlp?

You can solve this using intlinprog. This is probably not the most efficient way of solving the problem, but reliable A = [0 1 ...

Optimizing a matrix with cplexlp?

You can solve this using intlinprog. This is probably not the most efficient way of solving the problem, but reliable A = [0 1 ...

6 mois ago | 1

Answered

How SVD works for dimensionality reduction?

There's the svd function. The link points to the doc which has examples of how to use it.

How SVD works for dimensionality reduction?

There's the svd function. The link points to the doc which has examples of how to use it.

6 mois ago | 0

| accepted

Answered

chol fails on Hermitian positive definite matrix?

That is astonishing. The matrix is not badly conditioned, I would expect CHOL to work fine here. I tried on my machine and didn...

chol fails on Hermitian positive definite matrix?

That is astonishing. The matrix is not badly conditioned, I would expect CHOL to work fine here. I tried on my machine and didn...

7 mois ago | 0

| accepted

Answered

Sparsest solution for A\B

That statement is wrong, x = A\b doesn't return the solution x with the smallest number of nonzero elements. What mldivide does,...

Sparsest solution for A\B

That statement is wrong, x = A\b doesn't return the solution x with the smallest number of nonzero elements. What mldivide does,...

7 mois ago | 2

| accepted

Answered

eigs function: incorrect eigenvalues

The problem is that the matrix A is badly conditioned: >> cond(full(A)) ans = 2.206837183464466e+16 This is just around...

eigs function: incorrect eigenvalues

The problem is that the matrix A is badly conditioned: >> cond(full(A)) ans = 2.206837183464466e+16 This is just around...

7 mois ago | 2

Answered

Plotting eigenmodes in 3D

Depending on the format of your 3D-frame, maybe you could use pdeplot3d.

Plotting eigenmodes in 3D

Depending on the format of your 3D-frame, maybe you could use pdeplot3d.

7 mois ago | 0

Answered

matchpairs function in r2019a

The algorithm solves the same problem as the Hungarian algorithm, but it's not the same algorithm. The Hungarian algorithm has c...

matchpairs function in r2019a

The algorithm solves the same problem as the Hungarian algorithm, but it's not the same algorithm. The Hungarian algorithm has c...

7 mois ago | 0

| accepted

Answered

Hungarian algorithm realizated in matlab

As of R2019a, there is a function matchpairs in core MATLAB (no toolboxes needed) that solves the same problem as the Hungarian ...

Hungarian algorithm realizated in matlab

As of R2019a, there is a function matchpairs in core MATLAB (no toolboxes needed) that solves the same problem as the Hungarian ...

7 mois ago | 0

Answered

Hungary algorithm

As of R2019a, there is a function matchpairs in core MATLAB (no toolboxes needed) that solves the same problem as the Hungarian ...

Hungary algorithm

As of R2019a, there is a function matchpairs in core MATLAB (no toolboxes needed) that solves the same problem as the Hungarian ...

7 mois ago | 1