Displaying 20 results from an estimated 7000 matches similar to: "using R's svd from outside R"
2011 Jan 11
0
SVD, UV-Decomposition and NMF
I am reading the Mining of Massive Datasets Book by Rajaraman and
Ullman. It has a good explanation of Recommendation System at Chapter
9.
But what are the relationship between
1) SVD (Singular Decomposition)
2) UV-Decomposition
3) NMF (Non-negative Matrix Factorization)
In particular, it seems 2) and 3) can be very similar. Is it right?
Thanks.
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2004 Apr 30
1
calculation of U and V matrix of SVD decomposition (according to LINPACK, X = UDV')
Hello,
Like QR decomposition, I am looking for decomposition to get U and V matrix
of SVD decomposition (according to LINPACK, X = UDV'). Do you know if there
is a function which could calculate this decomposition?
Look forward to your reply,
Haleh
2008 Apr 15
1
SVD of a variance matrix
Hello!
I suppose this is more a matrix theory question than a question on R,
but I will give it a try...
I am using La.svd to compute the singular value decomposition (SVD) of
a variance matrix, i.e., a symmetric nonnegative definite square
matrix. Let S be my variance matrix, and S = U D V' be its SVD. In my
numerical experiments I always got U = V. Is this necessarily the
case? Or I might
2008 May 16
1
Dimensions of svd V matrix
Hi,
I'm trying to do PCA on a n by p wide matrix (n < p), and I'd like to
get more principal components than there are rows. However, svd() only
returns a V matrix of with n columns (instead of p) unless the argument
nv=p is set (prcomp calls svd without setting it). Moreover, the
eigenvalues returned are always min(n, p) instead of p, even if nv is set:
> x <-
2009 Jan 26
0
Spectral analysis with mtm-svd Multi-Taper Method Combined with Singular Value Decomposition
Hi list,
Does anyone know if there is a library in R that does MTM-SVD method for
spectral analysis?
Thanks
-----
Yasir H. Kaheil
Columbia University
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2003 Jul 03
2
SVD and spectral decompositions of a hermitian matrix
Hi:
I create a hermitian matrix and then perform its singular value
decomposition. But when I put it back, I don't get the original
hermitian matrix. I am having the same problem with spectral value
decomposition as well.
I am using R 1.7.0 on Windows. Here is my code:
X <- matrix(rnorm(16)+1i*rnorm(16),4)
X <- X + t(X)
X[upper.tri(X)] <- Conj(X[upper.tri(X)])
Y <-
2011 Sep 13
1
SVD Memory Issue
I am trying to perform Singular Value Decomposition (SVD) on a Term Document
Matrix I created using the 'tm' package. Eventually I want to do a Latent
Semantic Analysis (LSA).
There are 5677 documents with 771 terms (the DTM is 771 x 5677). When I try
to do the SVD, it runs out of memory. I am using a 12GB Dual core Machine
with Windows XP and don't think I can increase the memory
2008 Feb 23
1
Error in ma.svd(X, 0, 0) : 0 extent dimensions
Hi,
I run a maanova analysis and found this message error:
Error in ma.svd(X, 0, 0) : 0 extent dimensions
I did a google search and found this:
\item ma.svd: function to compute the sigular-value decomposition
of a rectangular matrix by using LAPACK routines DEGSVD AND ZGESVD.
\item fdr: function to calculate the adjusted P values for FDR control.
I did a search for LAPACK and
2009 Aug 09
1
Inaccuracy in svd() with R ubuntu package
On two laptops running 32-bit kubuntu, I have found that svd(), invoked
within R 2.9.1 as supplied with the current ubuntu package, returns very
incorrect results when presented with complex-valued input. One of the
laptops is a Dell D620, the other a MacBook Pro. I've also verified the
problem on a 32-bit desktop. On these same systems, R compiled from
source provides apparently
2012 Dec 05
1
Understanding svd usage and its necessity in generalized inverse calculation
Dear R-devel:
I could use some advice about matrix calculations and steps that might
make for faster computation of generalized inverses. It appears in
some projects there is a bottleneck at the use of svd in calculation
of generalized inverses.
Here's some Rprof output I need to understand.
> summaryRprof("Amelia.out")
$by.self
self.time self.pct
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
2000 Aug 10
1
svd error (PR#631)
--=====================_24736660==_
Content-Type: text/plain; charset="iso-8859-1"; format=flowed
Content-Transfer-Encoding: quoted-printable
SVD-Error on
R 1.1.0
Windows 98
I get the following error applying svd on a positive definite matrix :
> sk2
[,1] [,2] [,3] [,4] [,5]
[1,] 1.0460139783 0.084356992 -2.810553e-04
2010 Jan 16
2
La.svd of a symmetric matrix
Dear R list users,
the singluar value decomposition of a symmetric matrix M is UDV^(T), where U = V.
La.svd(M) gives as output three elements: the diagonal of D and the two orthogonal matrices u and vt (which is already the transpose of v).
I noticed that the transpose of vt is not exactly u. Why is that?
thank you for your attention and your help
Stefano
AVVISO IMPORTANTE: Questo messaggio di
2012 Apr 02
0
STL decomposition of time series with multiple seasonalities
Hi all,
I have a time series that contains double seasonal components (48 and 336) and I would like to decompose the series into the following time series components (trend, seasonal component 1, seasonal component 2 and irregular component). As far as I know, the STL procedure for decomposing a series in R only allows one seasonal component, so I have tried decomposing the series twice. First,
2010 Jul 06
1
using svd in regression with arima
Dear R Developers:
Why is it that the singular value decomposition is used when running regression with arima, please? I've been looking for a reference for that but have come up empty so far.
Thank you for any help.
Sincerely,
Erin
Erin M. Hodgess, PhD
Associate Professor
Department of Computer and Mathematical Sciences
University of Houston - Downtown
mailto: hodgesse@uhd.edu
2007 Oct 17
3
Observations on SVD linpack errors, and a workaround
Lately I'm getting this error quite a bit:
Error in La.svd(x, nu, nv) : error code 1 from Lapack routine 'dgesdd'
I'm running R 2.5.0 on a 64 bit Intel machine running Fedora (8 I think).
Maybe the 64 bit platform is more fragile about declaring convergence.
I'm seeing way more of these errors than I ever have before.
From R-Help I see that this issue comes up from time to
2004 Jul 01
1
QR decomposition and rank of a matrix
In summary.manova the qr decomposition of a NxN
matrix
is calculated and for some cases is giving me
a rank < N.
However, following suggestions of professor Ripley to
calculate the rank of a Matrix
On 7 Jun 2002, Brian Ripley wrote:
> For a more reliable answer, look at the SVD
> (function svd) and look at the
> singular values. For example (from lda.default)
X.s <-
2009 Mar 29
1
Data decomposition
Hi R users,
I have a time series variable that is only available at a monthly level for
1 years that I need to decompose to a weekly time series level - can
anyone recommend a R function that I can use to decompose this series?
eg. if month1 = 1200 I would to decompose so that the sum of the weeks for
month1 equals 1200, etc..
Many thanks in advance for any help.
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2007 Feb 27
2
ts; decompose; plot and title
Is there any way to give a "decent" title after I plot something
generated by decompose?
For example:
# generate something with period 12
x <- rnorm(600) + sin(2 * pi * (1:600) / 12)
# transform to a monthy time series
y <- ts(x, frequency=12, start=c(1950,1))
# decompose
z <- decompose(y)
# plot
plot(z)
Now, the title is the ugly "Decomposition of additive time
2004 Mar 26
1
Using R's LAPACK & Related files in Visual C++
I am a relative newcomer to both the R and C/C++
software worlds -- I'm taking a C Programming class
currently. I noticed the other day that the
C:\Program Files\R1_8_1\src\include\R_ext
directory on my WinXP box has the header files
BLAS.h
Lapack.h
Linpack.h
RLapack.h
I am interested in (perhaps) using one or more of
these
header files in a straight C program I'm working on in
Visual