답변 있음
How to find the permutation matrix for the qr decomposition?
I'm afraid using the three-output syntax is the only way. You can use [~, ~, p] = qr(A); but Q and R are still computed,...

대략 8년 전 | 0

답변 있음
Nonconvex: Checking positive-s​emidefinit​eness inside the Gloptipoly package
For positive definiteness, I would recommended to check this using CHOL (see if the second output registers a problem), but this...

대략 8년 전 | 0

| 수락됨

답변 있음
Order of eigenvalues depending on matrix equation order of operations
The reason for the difference in this case is that matrix B is exactly symmetric, and matrix A is not. EIG detects if the input ...

대략 8년 전 | 1

| 수락됨

답변 있음
Examining entries in binary matrices and creating new group matrix based on % of connections (defined by 1)
If you have each matrix stored in a separate variable, you can do Atotal = A1 + A2 + A3; % Sum of logical matrices is...

대략 8년 전 | 0

답변 있음
inverse of matrix times vector
The problem is probably that the vector x is not exactly symmetric (because of floating-point errors). You can try just symmetri...

대략 8년 전 | 0

| 수락됨

답변 있음
How to view/plot decomposed matrix from decomposition function
Hi, I'm afraid the decomposition object does not provide access to the factors of the decomposition. This is because, dependi...

대략 8년 전 | 0

답변 있음
Eigenvalues of a 2000x2000 matrix
EIG chooses between the symmetric and non-symmetric solver based on whether the matrix is exactly symmetric (A == A'). I'm guess...

대략 8년 전 | 0

답변 있음
graphshortestpath function visiting all nodes
As Steve Lord has said, in general this is an NP-complete problem, so could become quite expensive. For the 6-node graph you are...

대략 8년 전 | 1

답변 있음
How does matlabs eigs normalise eigenvectors?
If the matrix B is symmetric positive definite, the eigenvectors are normalized in B-norm (and even orthogonal in B-norm if A is...

대략 8년 전 | 0

답변 있음
Preserving node names in a digraph
Unfortunately, there is no direct way of doing this. The graph and digraph classes are designed to be fast when working on an ex...

대략 8년 전 | 0

답변 있음
What is the space complexity of built-in eigs function in MATLAB
The largest memory requirement for |eigs| is for an array that stores a subspace of vectors, which has |size(A, 1)| rows and a n...

대략 8년 전 | 1

| 수락됨

답변 있음
Using plot to generate a graph of a directed graph, how can i turn off the color of some lines
You can set the LineStyle property of these edges to 'none', which will make them not display. p = plot(gr4,'layout','circl...

대략 8년 전 | 0

답변 있음
Error when plotting a small digraph
This bug was fixed in R2016b. I'm afraid there is no workaround except to check for the error and use another layout method ('ci...

대략 8년 전 | 0

| 수락됨

답변 있음
Matlab code for this type of factorization.A has a SR decomposition A = SR , where S ∈ R^ 2n ×2n is a symplectic matrix, i.e. S ^TJS = J
I'm not very acquainted with the SR decomposition (all I know about it I found just now by googling). I would suggest to take a ...

대략 8년 전 | 0

| 수락됨

답변 있음
I have make a code for block Kronecker product when both A and B have even dimension now myquestion (I want to make a code when A and B have are not even and also A is square and B is rectangular and vice versa)
I'm not sure how to do this, but take a look at the implementation of |kron| in MATLAB: edit kron.m You'll see that it us...

대략 8년 전 | 0

| 수락됨

답변 있음
How to create a matrix B=[bij]=[max(i,j)] belongs to class of rectangular matrices
Focusing on the max(i, j) part, you could use i = 3; j = 4; B = max((1:i)', (1:j));

대략 8년 전 | 0

답변 있음
How can I find a matrix which is orthogonal to another matrix?
The concept of orthogonality for a matrix is defined for just one matrix: A matrix is orthogonal if each of its column vectors i...

8년 초과 전 | 0

답변 있음
Some questions on out of memory issues
Hi, 1- The eig function makes an internal copy of the input matrix, because the algorithm for computing the eigenvalues modif...

8년 초과 전 | 1

답변 있음
SVDS fails to find the requested number of singular values
The algorithm used in SVDS was rewritten for R2016a (and Name-Value pairs such as 'SubspaceDimension' were added in R2017b - the...

8년 초과 전 | 0

| 수락됨

답변 있음
Error in eigs when using Matlab 2017b?
Thank you for pointing out this bug. There is now a <https://www.mathworks.com/support/bugreports/1724250 bug report> available ...

8년 초과 전 | 1

답변 있음
I am experiecing strange behavior with mrdivide/ mldivide and sparse/full matrices. How can I optimize my code ?
There is a bug in R2017a and R2017b which makes the MA57 solver work significantly more slowly (a necessary pre-processing step ...

8년 초과 전 | 2

| 수락됨

답변 있음
Solving A{k} * x + b = 0 for large numbers of A{k} with same structure/filling.
In Tim Davis' C++ library UMFPACK, there are two phases to computing the decomposition of a matrix: The first one only uses the ...

8년 초과 전 | 2

| 수락됨

답변 있음
singular matrix inverse using svd in 2016 and 2013 version of a matlab
Take a look at the code of PINV ( |edit pinv| ), which is using the SVD to compute the pseudo-inverse of a matrix. |x = pinv(A)*...

8년 초과 전 | 1

답변 있음
MATLAB 2016a and 2017a give different results when multiplying by the complex conjugate
This is wrong behavior: the diagonal of matrix Rxx should have zero imaginary part. We will work on fixing this for a future rel...

8년 초과 전 | 0

| 수락됨

답변 있음
Eigen values Form : A*[phi] = beta*B*[phi]
[U, D] = eig(A, B); gives you what you are looking for. All possible values of beta (eigenvalues of (A, B)) are on the diago...

8년 초과 전 | 0

| 수락됨

답변 있음
Get node names after a graph condensation
Here is some code that does this: bins = conncomp(G); compNames = cell(max(bins), 1); for ii=1:length(bins) if ise...

8년 초과 전 | 4

| 수락됨

답변 있음
MATLAB crashing when trying to solve 100k x 100k linear system
On Linux and Mac, programs that use nearly all of the system memory are sometimes killed by the operating system, in such a way ...

8년 초과 전 | 1

답변 있음
How to do Delaunay Triangulation and return an adjacency matrix?
If your goal in computing the adjacency matrix is to construct a graph object, you can also do that (a bit) more directly: %...

8년 초과 전 | 1

| 수락됨

답변 있음
eig() gives a negative eigenvalue for a positive semi-definite matrix
While A*A' is mathematically symmetric positive semi-definite, its numeric representation will not be - it's more like A*A' + (r...

8년 초과 전 | 3

답변 있음
How does the eig function calculate its values?
Could you tell us what your results are? Eigenvectors are not uniquely defined, so it's possible for them to look quite differen...

8년 초과 전 | 1

더 보기