Displaying 20 results from an estimated 4000 matches similar to: "find the eigenvector corresponding to the largest eigenvalue"
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
2007 Jun 29
4
Dominant eigenvector displayed as third (Marco Visser)
Dear R users & Experts,
This is just a curiousity, I was wondering why the dominant eigenvetor and eigenvalue
of the following matrix is given as the third. I guess this could complicate automatic selection
procedures.
0 0 0 0 0 5
1 0 0 0 0 0
0 1 0 0 0 0
0 0 1 0 0 0
0 0 0 1 0 0
0 0 0 0 1 0
Please
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
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)
$values
[1]
1999 Apr 20
2
eigenvalue/eigenvector calculations
Some of you may have seen a message on s-news by Stefan Steinhaus
regarding his paper on "Comparison of mathematical programs for data
analysis". He compares S-PLUS 4.5 with several other programs. He
does not include R in the comparisons. On p. 28 of his report he
gives the URL the Auckland site along with URL's for two other systems
but comments that "I didn't received
2010 Jun 25
2
Forcing scalar multiplication.
I am trying to check the results from an Eigen decomposition and I need to force a scalar multiplication. The fundamental equation is: Ax = lx. Where 'l' is the eigen value and x is the eigen vector corresponding to the eigenvalue. 'R' returns the eigenvalues as a vector (e <- eigen(A); e$values). So in order to 'check' the result I would multiply the eigenvalues
2009 Apr 23
1
the definition of eigenvector in R
Dear All
i have a little puzzle about eigenvector in the R.
As we know that the eigenvector can be displayed on several form.
For example
A=matrix(c(1,2,4,3),2,2)
if we want to get the eigenvalue and eigenvector, the code followed
eigen(A)
$values
[1] 5 -1
$vectors
[,1] [,2]
[1,] -0.7071068 -0.8944272
[2,] -0.7071068 0.4472136
however, we also can calculate the vector matrix
2003 Feb 06
6
Confused by SVD and Eigenvector Decomposition in PCA
Hey, All
In principal component analysis (PCA), we want to know how many percentage
the first principal component explain the total variances among the data.
Assume the data matrix X is zero-meaned, and
I used the following procedures:
C = covriance(X) %% calculate the covariance matrix;
[EVector,EValues]=eig(C) %%
L = diag(EValues) %%L is a column vector with eigenvalues as the elements
percent
2010 Jun 12
1
Fast way to compute largest eigenvector
Hello all,
I was wondering if there is a function in R that only computes the eigenvector
corresponding to the largest/smallest eigenvalue of an arbitrary real matrix.
Thanks
Minh
--
Living on Earth may be expensive, but it includes an annual free trip
around the Sun.
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 Aug 03
3
prcomp eigenvalues
Hello,
Can you get eigenvalues in addition to eigevectors using prcomp? If so how?
I am unable to use princomp due to small sample sizes.
Thank you in advance for your help!
Rebecca Young
--
Rebecca Young
Graduate Student
Ecology & Evolutionary Biology, Badyaev Lab
University of Arizona
1041 E Lowell
Tucson, AZ 85721-0088
Office: 425BSW
rlyoung at email.arizona.edu
(520) 621-4005
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
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
2003 Apr 03
2
Matrix eigenvectors in R and MatLab
Dear R-listers
Is there anyone who knows why I get different eigenvectors when I run
MatLab and R? I run both programs in Windows Me. Can I make R to produce
the same vectors as MatLab?
#R Matrix
PA9900<-c(11/24 ,10/53 ,0/1 ,0/1 ,29/43 ,1/24 ,27/53 ,0/1 ,0/1 ,13/43
,14/24 ,178/53 ,146/244 ,17/23 ,15/43 ,2/24 ,4/53 ,0/1 ,2/23 ,2/43 ,4/24
,58/53 ,26/244 ,0/1 ,5/43)
#R-syntax
2005 Jun 16
2
Computing generalized eigenvalues
I need to compute generalized eigenvalues. The eigen function in base
doesn't do it and I can't find a package that does.
As I understand it, Lapack __can__ computer them
(http://www.netlib.org/lapack/lawn41/node111.html) and R can use
Lapack. If there is no function already, can I access Lapack from R
and use those routines directly?
Thank you,
Joshua Gilbert.
2012 Mar 09
1
Eigenvalue calculation of sparse matrices
Dear all,
I am currently working on the calculation of eigenvalues (and -vectors)
of large matrices. Since these are mostly sparse matrices and I remember
some specific functionalities in MATLAB for sparse matrices, I started a
research how to optimize the calculation of eigenvalues of a sparse matrix.
The function eigen itself works with the LAPACK library which has no
special handling for
2008 Jun 18
2
highest eigenvalues of a matrix
DeaR list,
I happily use eigen() to compute the eigenvalues and eigenvectors of
a fairly large matrix (200x200, say), but it seems over-killed as its
rank is limited to typically 2 or 3. I sort of remember being taught
that numerical techniques can find iteratively decreasing eigenvalues
and corresponding orthogonal eigenvectors, which would provide a nice
alternative (once I have the
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
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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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