Displaying 20 results from an estimated 5000 matches similar to: "highest eigenvalues of a matrix"
2005 May 02
14
eigenvalues of a circulant matrix
Hi,
It is my understanding that the eigenvectors of a circulant matrix are given as
follows:
1,omega,omega^2,....,omega^{p-1}
where the matrix has dimension given by p x p and omega is one of p complex
roots of unity. (See Bellman for an excellent discussion on this).
The matrix created by the attached row and obtained using the following
commands
indicates no imaginary parts for the
2006 Oct 18
1
Calculation of Eigen values.
Dear all R users,
Can anyone tell me to calculate Eigen value of any real symmetric matrix
which algorithm R uses? Is it Jacobi method ? If not is it possible to get
explicit algorithm for calculating it?
Thanks and regards,
Arun
[[alternative HTML version deleted]]
2015 Jan 31
2
error code 1 from Lapack routine 'dsyevr'
Hi,
I got an error message in my program saying
"Error in eigen(gene_intersection.kernel) :
error code 1 from Lapack routine 'dsyevr'
Execution halted".
As you see, I was trying to compute the eigenvalues of a matrix but got this
error. Is there anyone who knows what this error means and how I can fix it?
Theoretically the eigenvalues should be nonnegative, if it helps.
2011 Nov 14
2
How to compute eigenvectors and eigenvalues?
Hello.
Consider the following matrix:
mp <- matrix(c(0,1/4,1/4,3/4,0,1/4,1/4,3/4,1/2),3,3,byrow=T)
> mp
[,1] [,2] [,3]
[1,] 0.00 0.25 0.25
[2,] 0.75 0.00 0.25
[3,] 0.25 0.75 0.50
The eigenvectors of the previous matrix are 1, 0.25 and 0.25 and it is not a diagonalizable matrix.
When you try to find the eigenvalues and eigenvectors with R, R responses:
> eigen(mp)
$values
[1]
2004 Oct 19
3
matrix of eigenvalues
I thought that the function
eigen(A)
will return a matrix with eigenvectors that are independent of each
other (thus forming a base and the matrix being invertible). This
seems not to be the case in the following example
A=matrix(c(1,2,0,1),nrow=2,byrow=T)
eigen(A) ->ev
solve(ev$vectors)
note that I try to get the upper triangular form with eigenvalues on
the diagonal and (possibly) 1 just
2015 Feb 02
5
error code 1 from Lapack routine 'dsyevr'
Thank you for your reply. Do you have any idea of how to get rid of the
errors? I tried Null function to calculate eigenvectors and nearPD to get
approximate positive definite matrix first but they also had errors.
--
View this message in context: http://r.789695.n4.nabble.com/error-code-1-from-Lapack-routine-dsyevr-tp4702571p4702639.html
Sent from the R devel mailing list archive at
2008 Jun 03
3
matlab eigs function in R
Hello
Does anybody know how one can compute d largest eigenvalues/eigenvectors in
R, like in MATLAB eigs function ? eigen function computes all
eigenvectors/eigenvalues, and they are slightly different than those
generated by matlab eigs.
Thanks in advance
--
View this message in context: http://www.nabble.com/matlab-eigs-function-in-R-tp17619641p17619641.html
Sent from the R help mailing list
2012 Apr 19
3
Solve an ordinary or generalized eigenvalue problem in R?
Folks:
I'm trying to port some code from python over to R, and I'm running into a
wall finding R code that can solve a generalized eigenvalue problem
following this function model:
http://docs.scipy.org/doc/scipy/reference/generated/scipy.linalg.eig.html
Any ideas? I don't want to call python from within R for various reasons,
I'd prefer a "native" R solution if one
2012 Apr 27
2
find the eigenvector corresponding to the largest eigenvalue
Hi,
If I use the eigen() function to find the eigenvalues of a matrix, how can I find the eigenvector corresponding to the largest eigen value?
Thanks!
[[alternative HTML version deleted]]
2005 May 03
2
Fwd: Re: eigenvalues of a circulant matrix
Looks like the files did not go through again. In any case, here is the kinv:
please cut and paste and save to a file:
-1.16801E-03 -2.24310E-03 -1.16864E-03 -2.24634E-03 -1.17143E-03
-2.25358E-03 -1.17589E-03 -2.26484E-03 -1.18271E-03 -2.27983E-03
-1.19124E-03 -2.29896E-03 -1.20164E-03 -2.32206E-03 -1.21442E-03
-2.34911E-03 -1.22939E-03 -2.38073E-03
1997 May 18
2
R-alpha: Eigenvalue Computation Query
I have been looking at the "eigen" function and have reintroduced the
ability to compute (right) eigenvalues and vectors for non-symmetric
matrices. I've also made "eigen" complex capable.
The code is based on the eispack entry points RS, RG, CH, CG (which is
what S appears to use too). The problem with both the S and R
implementations is that they consume huge amounts
2009 Apr 24
1
the puzzle of eigenvector and eigenvalue
Dear all
I am so glad the R can provide the efficient calculate about
eigenvector and eigenvalue.
However, i have some puzzle about the procedure of eigen.
Fristly, what kind of procedue does the R utilize such that the eigen
are obtained?
For example, A=matrix(c(1,2,4,3),2,2)
we can define the eigenvalue lamda, such as
det | 1-lamda 4 | =0
| 2 3-lamda |
then
2006 Jan 18
1
function 'eigen' (PR#8503)
Full_Name: Pierre Legendre
Version: 2.1.1
OS: Mac OSX 10.4.3
Submission from: (NULL) (132.204.120.81)
I am reporting the mis-behaviour of the function 'eigen' in 'base', for the
following input matrix:
A <- matrix(c(2,3,4,-1,3,1,1,-2,0),3,3)
eigen(A)
I obtain the following results, which are incorrect for eigenvalues and
eigenvectors 2 and 3 (incorrect imaginary portions):
2010 Jan 11
3
Eigenvectors and values in R and SAS
Hi,
I was wondering if function eigen() does something different from the
function call eigen() in SAS.
I'm in the process of translating a SAS code into a R code and the values of
the eigenvectors and eigenvalues of a square matrix came out to be different
from the values in SAS.
I would also appreciate it if someone can explain the difference in simple
terms. I'm pretty new to both
2010 Jun 25
2
Forcing scalar multiplication.
I am trying to check the results from an Eigen decomposition and I need to force a scalar multiplication. The fundamental equation is: Ax = lx. Where 'l' is the eigen value and x is the eigen vector corresponding to the eigenvalue. 'R' returns the eigenvalues as a vector (e <- eigen(A); e$values). So in order to 'check' the result I would multiply the eigenvalues
2005 Apr 25
1
The eigen function
I'm using R version 2.0.1 on a Windows 2000 operating system. Here is some
actual code I executed:
> test
[,1] [,2]
[1,] 1000 500
[2,] 500 250
> eigen(test, symmetric=T)$values
[1] 1.250000e+03 -3.153033e-15
> eigen(test, symmetric=T)$values[2] >= 0
[1] FALSE
> eigen(test, symmetric=T, only.values=T)$values
[1] 1250 0
> eigen(test, symmetric=T,
2002 Nov 05
2
eigenvectors order
Hi,
How the eigenvectors output by the eigen() function are ordered. The
first column corresponds to the largest eigenvalue? or is the last
column as in Octave?
I'm performing a spatial-temporal analysis of some climatic variables
so my matrices are MxN (locations*time)and I'm looking for the leading
EOF's. As I have understand the eigenvectors columns represent those
EOF's
2004 Apr 07
1
eigenvalues for a sparse matrix
Hi,
I have the following problem. It has two parts.
1. I need to calculate the stationary probabilities of a Markov chain,
eg if the transition matrix is P, I need x such that
xP = x
in other words, the left eigenvectors of P which have an eigenvalue of
one.
Currently I am using eigen(t(P)) and then pick out the vectors I need.
However, this seems to be an overkill (I only need a single
2013 May 19
1
Generate positive definite matrix with constraints
Hi, I have a question for my simulation problem:
I would like to generate a positive (or semi def positive) covariance
matrix, non singular, in wich the spectral decomposition returns me the same
values for all dimensions but differs only in eigenvectors.
Ex.
sigma
[,1] [,2]
[1,] 5.05 4.95
[2,] 4.95 5.05
> eigen(sigma)
$values
[1] 10.0 0.1
$vectors
[,1]
2004 Nov 05
1
fast partial spectral decompositions.
hello,
i want to compute the top k eigenvalues+eigenvectors of a (large)
real symmetric matrix. since it doesn't look like any top-level R
function does this, i'll call LAPACK from a C shlib and then
use .Call. the only LAPACK function i see to do this in
R_ext/Lapack.h is dsyevx. however, i know that in LAPACK dsyevr
can also return a partial eigendecomposition. why is dsyevr not