Displaying 20 results from an estimated 7000 matches similar to: "function "eigen" AND Minitab"
2006 Mar 03
1
NA in eigen()
Hi,
I am using eigen to get an eigen decomposition of a square, symmetric
matrix. For some reason, I am getting a column in my eigen vectors (the
52nd column out of 601) that is a column of all NAs. I am using the option,
symmetric=T for eigen. I just discovered that I do not get this behavior
when I use the option EISPACK=T. With EISPACK=T, the 52nd eigenvector is
(up to rounding error) a
2005 Jul 04
1
eigen of a real pd symmetric matrix gives NaNs in $vector (PR#7987)
Full_Name: cajo ter Braak
Version: 2.1.1
OS: Windows
Submission from: (NULL) (137.224.10.105)
# I would like to attach the matrix C in the Rdata file; it is 50x50 and comes
from a geostatistical problem (spherical covariogram)
> rm(list=ls(all=TRUE))
> load(file= "test.eigen.Rdata")
> ls()
[1] "C" "eW"
>
> sym.check = max(abs(C - t(C))) # should
2003 Jun 09
1
understanding eigen(): getting non-normalized eigenvectors
Hi, dear R pros
I try to understand eigen(). I have seen, that eigen() gives the
eigenvectors normalized to unit length.
What shall I do to get the eigenvectors not normalized to unit length?
E.g. take the example:
A
[,1] [,2]
V1 0.7714286 -0.2571429
V2 -0.4224490 0.1408163
Calculating eigen(A) "by hand" gives the eigenvectors (example from
Backhaus,
2013 Jun 18
1
eigen(symmetric=TRUE) for complex matrices
R-3.0.1 rev 62743, binary downloaded from CRAN just now; macosx 10.8.3
Hello,
eigen(symmetric=TRUE) behaves strangely when given complex matrices.
The following two lines define 'A', a 100x100 (real) symmetric matrix
which theoretical considerations [Bochner's theorem] show to be positive
definite:
jj <- matrix(0,100,100)
A <- exp(-0.1*(row(jj)-col(jj))^2)
A's being
2006 Aug 10
3
Geometrical Interpretation of Eigen value and Eigen vector
Dear all,
It is not a R related problem rather than statistical/mathematical. However
I am posting this query hoping that anyone can help me on this matter. My
problem is to get the Geometrical Interpretation of Eigen value and Eigen
vector of any square matrix. Can anyone give me a light on it?
Thanks and regards,
Arun
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2005 Apr 25
1
The eigen function
I'm using R version 2.0.1 on a Windows 2000 operating system. Here is some
actual code I executed:
> test
[,1] [,2]
[1,] 1000 500
[2,] 500 250
> eigen(test, symmetric=T)$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,
2008 Mar 03
1
Extracting data from Eigen function
Hi
I need to extract the data returned by Eigen to plot the eigenvectors.
However, when I try and eigv = eigen(covariance); it returns an object with
the matrices containing eigenvalues and vectors.. how can I extract the
eigenvector matrix from this??
When I try mat = eig["vectors"] it returns a matrix with the "$vectors"
string on top , how can I remove this?
code:
> eig
2010 Mar 19
1
Howto get unnormalized eigenvectors?
Hi,
I try to calculate the angle between two first eigenvectors of different covariance matrices of biological phenotypic traits for different populations. My issue here is, that all possibilities to do so seem to normalize the eigenvectors to length 1. Although the helpfile of eigen() states, that using eigen(, symmetric = FALSE, EISPACK =TRUE) skips normalization this is (I guess) not applicable
2006 Mar 28
2
R crashes during 'eigen'
Hi all,
Hi,
When I want to compute the eigenvalues & eigenvectors of a specific
matrix, R crashes (i.e. it stops responding to any input). I've tried it
with different versions of R (2.1.1, 2.2.0, 2.2.1) - all with crashing
as result.
What I did before the crash was:
M <- as.matrix(read.table("thematrix",header=T))
eigen(M)
If, instead of eigen(M), I use eigen(M,
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
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2007 Nov 29
1
?eigen documentation suggestion
from ?eigen
symmetric: if 'TRUE', the matrix is assumed to be symmetric (or
Hermitian if complex) and only its lower triangle is used. If
'symmetric' is not specified, the matrix is inspected for
symmetry.
I think that could mislead a naive reader as it suggests that, with symmetric=TRUE,
the result of eigen() (vectors and values) depends only on
2005 May 01
2
eigen() may fail for some symmetric matrices, affects mvrnorm()
Hi all,
Recently our statistics students noticed that their Gibbs samplers were
crashing due to some NaNs in some parameters. The NaNs came from
mvrnorm (Ripley & Venables' MASS package multivariate normal sampling
function) and with some more investigation it turned out that they were
generated by function eigen, the eigenvalue computing function. The
problem did not seem to happen
2005 Jul 04
0
eigen of a real pd symmetric matrix gives NaNs in $vector (PR#7989)
I would presume this is another manifestation of what I reported
(reproduced below) on 2003-12-01.
cajo.terbraak at wur.nl wrote:
>Full_Name: cajo ter Braak
>Version: 2.1.1
>OS: Windows
>Submission from: (NULL) (137.224.10.105)
>
>
># I would like to attach the matrix C in the Rdata file; it is 50x50 and comes
>from a geostatistical problem (spherical covariogram)
>
2004 Feb 12
1
left eigenvector
Dear All,
how do I compute the left eigenvector of a matrix? I gather that "eigen"
computes the right eigenvectors...
Regards,
Federico Calboli
--
=================================
Federico C. F. Calboli
PLEASE NOTE NEW ADDRESS
Dipartimento di Biologia
Via Selmi 3
40126 Bologna
Italy
tel (+39) 051 209 4187
fax (+39) 051 251 208
f.calboli at ucl.ac.uk
2013 Jan 31
1
Using eigen() for extracting only few major eigenpairs
Hi everyone,
I am using eigen() to extract the 2 major eigenpairs from a large real
square symmetric matrix. The procedure is already rather efficient, but
becomes somehow slow for real time needs with moderately large matrices
(few thousand lines).
The R implementation statically extracts all eigenvalues (and optionally
associated eigenvectors). I heard about optimizations of the eigen
2009 Apr 24
1
the puzzle of eigenvector and eigenvalue
Dear all
I am so glad the R can provide the efficient calculate about
eigenvector and eigenvalue.
However, i have some puzzle about the procedure of eigen.
Fristly, what kind of procedue does the R utilize such that the eigen
are obtained?
For example, A=matrix(c(1,2,4,3),2,2)
we can define the eigenvalue lamda, such as
det | 1-lamda 4 | =0
| 2 3-lamda |
then
2010 Jun 25
2
Forcing scalar multiplication.
I am trying to check the results from an Eigen decomposition and I need to force a scalar multiplication. The fundamental equation is: Ax = lx. Where 'l' is the eigen value and x is the eigen vector corresponding to the eigenvalue. 'R' returns the eigenvalues as a vector (e <- eigen(A); e$values). So in order to 'check' the result I would multiply the eigenvalues
2003 Dec 22
1
La.eigen hangs R when NaN is present (PR#6003)
Full_Name: Sundar Dorai-Raj
Version: 1.8.1
OS: Windows 2000 Professional
Submission from: (NULL) (12.64.199.173)
I discovered this problem when trying to use princomp in package:mva when a
column in my matrix was all zeros and I set cor = TRUE (thus division by 0).
Doing so hangs R, never to return. I have to shut down Rterm in the Task Manager
and lose all work from the current image. I tracked
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!
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1997 May 01
0
R-alpha: eigen()
eigen() seems to work for symmetric matrices only. This is out of sync
with the help file.
> trpr.37
0 1 2 3 4
0 1.00000000 0.0000000 0.0000000 0.0000000 0.0000000
1 0.44444444 0.5555556 0.0000000 0.0000000 0.0000000
2 0.02439024 0.2439024 0.7317073 0.0000000 0.0000000
3 0.00000000 0.0000000 0.2307692 0.7692308 0.0000000
4 0.00000000 0.0000000