Displaying 20 results from an estimated 2000 matches similar to: "R analog of Matlab "eigs" function"
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
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2009 Dec 01
1
eigenvalues of complex matrices
Dear all,
I want to compute the eigenvalues of a complex matrix for some statistics.
Comparing it to its matlab/octave sibling, I don't get the same eigenvalues
in R computing it from the exact same matrix.
In R, I used eigen() and arpack() that give different eigenvalues. In
matlab/octave I used eig() and eigs() that give out the same eigenvalues but
different to the R ones.
For real
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
2011 May 23
0
storing data from loops
Dear R-help list,
I have a problem storing results from a bootstrap loop. What I doing is
creating an empty matrix before the loop, then run the loop. Before the end
of the loop I have a command line which defines which results inside the
loop will have to go in the empty matrix. Here is the code I am using:
eigen.values<-rep(NA,boots)
#storage file for eigen values (1 for simulation)
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
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
2007 May 08
1
Piecewise cubic Hermite interpolation
Which function implements the piecewise cubic Hermite interpolation?
I am looking for equivalent of matlab's interp1 with the method = 'pchip'
Here is the reference
http://www.mathworks.com/access/helpdesk/help/techdoc/index.html?/access/helpdesk/help/techdoc/ref/interp1.html&
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2008 Feb 20
0
igraph package, version 0.5
igraph is a package for graphs and networks. It has a C core and
uses a simple and fast graph representation allowing millions
of vertices and edges.
NEW FEATURES:
- We use the ARPACK library for graph related eigenvalue problems,
like Page Rank calculation, Kleinberg's hub and authority scores,
eigenvector centrality, etc. There is also a generic interface
if someone wants to use
2008 Feb 20
0
igraph package, version 0.5
igraph is a package for graphs and networks. It has a C core and
uses a simple and fast graph representation allowing millions
of vertices and edges.
NEW FEATURES:
- We use the ARPACK library for graph related eigenvalue problems,
like Page Rank calculation, Kleinberg's hub and authority scores,
eigenvector centrality, etc. There is also a generic interface
if someone wants to use
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
2007 Jul 18
1
Is there a facility in R similar to MatLab "syms" that allows using unevaluated numeric symbols in matrices?
Hi,
I'm trying to use R to get eigenvalues and eigenvectors of a matrix
whose elements are of the form (2 * lambda), -(lambda + mu), etc. I'd
like R to treat this matrix as a numeric matrix without treating lambda
and mu as variable names but rather as some sort of atomic quantities
(and hence give eigenvectors in terms of mu and/or lambda). MatLab and
Mathematica both do this,
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 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
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around the Sun.
2004 Aug 09
1
returns the value of a polynomial of degree n evaluated at x.
> Background:
> OS: Linux Mandrake 9.1
> release: R 1.9.0
> editor: Xemacs 21.4
> frontend: ESS 5.1.23
> ---------------------------------
>
> Colleagues
>
Is there a function in R that is similar to polyval in matlab? (y =
polyval(p,x) returns the value of a polynomial of degree n evaluated at x.
The input argument p is a vector of length n+1 whose elements are the
2011 Mar 30
2
calculating the mode in R...
Dear R users
I?m aware that the package ?modest? is useful to find the mode in an array.
However, I?d like to know if someone has translated the ?mode? function built-in
in MATLAB into R language. This function finds the most frequent value in an
array (http://www.mathworks.com/help/techdoc/ref/mode.html).
Best
Fer
2009 Mar 12
3
can I draw 3D plot like this using R?
hi, all
I am looking at R package RGL to draw a colored mesh/surface plot like
this one (from matlab).
http://www.mathworks.com/access/helpdesk/help/techdoc/visualize/cbar.gif
The key features I am looking for is surfaced with grid and color, but
not the terrain-like gradient. but I didn't come even close to it
after browsing through rgl help file.
have anyone drawn something like this
2007 Dec 23
2
Problem with dyn.load'ed code
Hi,
I am having trouble with some code that I am dyn.loading. I am
writing an interface to ARPACK. I compile my interface (dssimp.cc), and
link it against the ARPACK library (libarpack_SUN4.a):
g++ -shared -static -fPIC dssimp.cc -o dssimp.so -larpack_SUN4 -lg2c -lm
I can dyn.load the code and it appears OK. However, when I call my
function, the call to the function in the ARPACK library
2012 Aug 28
5
return first index for each unique value in a vector
I would like to efficiently find the first index of each unique value in a
very large vector.
For example, if I have a vector
A<-c(9,2,9,5)
I would like to return not only the unique values (2,5,9) but also their
first indices (2,4,1).
I tried using a for loop with which(A==unique(A)[i])[1] to find the first
index of each unique value but it is very slow.
What I am trying to do is easily
2006 Mar 13
0
wishlist: function mlh.mlm to test multivariate linear hypotheses of the form: LBT'=0 (PR#8680)
Full_Name: Yves Rosseel
Version: 2.2.1
OS:
Submission from: (NULL) (157.193.116.152)
The code below sketches a possible implementation of a function 'mlh.mlm' which
I think would be a good complement to the 'anova.mlm' function in the stats
package. It tests a single linear hypothesis of the form H_0: LBT'= 0 where B is
the matrix of regression coefficients; L is a matrix
2004 Aug 09
0
returns the value of a polynomial of degree n evaluated a t x.
Try something like:
install.packages("polynom")
library(polynom)
predict(polynomial(rev(p)), x)
HTH,
Andy
> From: McClatchie, Sam (PIRSA-SARDI)
>
> > Background:
> > OS: Linux Mandrake 9.1
> > release: R 1.9.0
> > editor: Xemacs 21.4
> > frontend: ESS 5.1.23
> > ---------------------------------
> >
> > Colleagues
> >