Displaying 20 results from an estimated 579 matches for "decomposition".
2017 Jul 19
2
STL - time series seasonal decomposition sensitive to data points?
Hi all,
I am trying to analyse a time series data and want to make
trend-season decomposition using STL approach in R. However I found
the decomposition result seems to be sensitive to data points even
with the robust option.
More specifically, suppose I have a few years of monthly data. Using
stl, I got a decomposition T1 + S1 + R1. Then I deleted the most
recent two or three data points,...
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
2009 Mar 10
5
Cholesky Decomposition in R
Hi everyone:
I try to use r to do the Cholesky Decomposition,which is A=LDL',so far I
only found how to decomposite A in to LL' by using chol(A),the function
Cholesky(A) doesnt work,any one know other command to decomposte A in to
LDL'
My r code is:
library(Matrix)
A=matrix(c(1,1,1,1,5,5,1,5,14),nrow=3)
> chol(A)
[,1] [,2] [,3]
[1,]...
2011 Nov 30
2
Generalized singular value decomposition
Hello,
I would like to perform a generalized singular value decomposition with
R. The only possibility I found is "GSVD" that is based on LAPACK/BLAS.
Are there other possibilities too?
If not, has anybody used LAPACK/BLAS under Windows XP? How can I install
them? Following [1] did not help.
I hope this is the right place for my question.
Thank you very mu...
2005 Jan 21
1
Cholesky Decomposition
Can we do Cholesky Decompositon in R for any matrix
---------------------------------
[[alternative HTML version deleted]]
2004 Aug 30
3
Generalized Singular Value Decomposition (GSVD)
Dear R-users,
I couldn't find a function or some help in R-project web about the
Generalized Singular Value Decomposition. In MatLab there is a simple
function for this algebric issue (gsvd). Is there anything like that in R?
And, if not, could you help me to apply this method in R?
Thanks in advance, Giancarlo
+++++
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2008 Mar 20
1
Interpretation of Variance decomposition in VAR model
...i all,
This question is not really R related, rather on Statistics subject itself. Even I did not do those using R. however still I want to post it here, because my hope is I could get help from great statisticians who are the very active member of this group.
My problem is to interpret Variance decomposition of VAR model in layman's language.
Using EViews I got following :
Variance Decomposition of LN_FU:
Period S.E. LN_SPOT LN_FU
1 0.024422 93.66959 6.330413
2 0.034838 94.36506 5.634938
3 0.042280 94.60712 5.392882
4 0.048540 94.30725 5.692747
5 0.054060 93.99039...
2003 Feb 06
6
Confused by SVD and Eigenvector Decomposition in PCA
...e 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 = L(1)/sum(L);
Others argue using Sigular Value Decomposition(SVD) to
calculate the same quantity, as:
[U,S,V]=svd(X);
L = diag(S);
L = L.^2;
percent = L(1)/sum(L);
So which way is the correct method to calculate the percentage explained by
the first principal component?
Thanks for your advices on this.
Fred
2005 Nov 23
1
assign() problem
I've written a piece of code (see below) to do a wavelet image
decomposition, during the evaluation of this code I would like to write
the results of some calculations back to the R root directory. I used
assign() to do so because the names should vary when going thrue a
while() loop. For some unknown reason I get an error that says:
Error in assign(varname[i], imwrIma...
2004 Jul 01
1
QR decomposition question
Hi all,
I wonder if this kind of questions are ok in this
list...
Quick question:
What does it mean than the rank of the QR
decomposition of a NxN matrix is N-1 ?
m: NxN matrix
qr(m)$rank equal to (N-1)
Long version:
I'm doing a manova on a matrix of 10 variables
and 16 observations.
> dim(tmp)
[1] 16 10
> fit <- manova( tmp ~ treatment*mouse )
>results <- summary(fit,test="Wilks")
...
resi...
2009 Feb 02
1
Beveridge Nelson Decomposition
Hi,
Would anyone know if it is possible to run a Beveridge Nelson decomposition
of a univariate time series object in R? I searched in the help files but
didn't come across any potential methods.
Thanks very much,
Shruthi
--
View this message in context: http://www.nabble.com/Beveridge-Nelson-Decomposition-tp21789452p21789452.html
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2009 Oct 16
2
what's the R code for wavelet decomposition (Haar transformation)?
Dear all,
Using R function "dwt", it seems that I cannot specify the wavelet
transformation like Haar. What's the R code for wavelet decomposition
which allows me to specify Haar wavelet transformation? Of course, if it
can include "db2", that is even better. In general, I want an R function
like matlab code "dwt". Thanks in advance!
Zhen Li
2006 Sep 01
1
Help with singular value decomposition
Hi wizards, I have seen the function svd of R for singular value
decomposition, but I need to computes the ``economy size'' or ``thin''
singular value decomposition of a matrix in R. Somebody knows how to
do that?. Thanks in advance.
--
Web Page
http://geocities.com/lord_tyranus_96/
2012 Apr 19
2
Is the eigen-value decomposition in R generally stable/reliable for large matrix?
Say a matrix of size of thousands?
I am looking for an eigen-value decomposition algo in R to give good
eigenvalues...
Is that a hopeful thing?
Thank you!
[[alternative HTML version deleted]]
2017 Jul 18
0
STL - time series seasonal decomposition sensitive to data points?
Hi all,
I am trying to analyse a time series data and want to make trend-season
decomposition using STL approach in R. However I found the decomposition
result seems to be sensitive to data points even with the robust option.
More specifically, suppose I have a few years of monthly data. Using stl, I
got a decomposition T1 + S1 + R1. Then I deleted the most recent two or
three data points,...
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)])...
2007 Jun 29
2
Spectral Decomposition
All of my resources for numerical analysis show that the spectral
decomposition is
A = CBC'
Where C are the eigenvectors and B is a diagonal matrix of eigen values.
Now, using the eigen function in R
# Original matrix
aa <- matrix(c(1,-1,-1,1), ncol=2)
ss <- eigen(aa)
# This results yields back the original matrix according to the formula
above
ss$vectors %*% di...
2009 Apr 01
2
Need Advice on Matrix Not Positive Semi-Definite with cholesky decomposition
Dear fellow R Users:
I am doing a Cholesky decomposition on a correlation matrix and get error message
the matrix is not semi-definite.
Does anyone know:
1- a work around to this issue?
2- Is there any approach to try and figure out what vector might be co-linear with another in thr Matrix?
3- any way to perturb the data to work around this?
Thanks f...
2006 Feb 14
0
ANOVA: Help with SSQ decomposition and contrasts
# Dear R list,
#
# A have a doubt about SSQ decomposition and contrasts with ANOVAs.
# So, I would like a tip from more advanced R users.
# Below my data, the basic script and my doubts:
# Data
r = paste('r', gl(3, 8), sep='')
e = paste('e', rep(gl(2, 4), 3), sep='')
tra = sort(paste('t', rep(1:6, 4), sep='...
2006 Feb 16
0
SSQ decomposition and contrasts with ANOVA
Dear R list,
Please, could someone help me with SSQ decomposition and contrasts.
Below my data, graphic, ANOVAs and my doubt:
# Data
a = paste('a', gl(3, 8), sep='')
b = paste('b', gl(2, 4, 24), sep='')
tra = sort(paste('t', rep(1:6, 4), sep=''))
y = c(26.2, 26.0, 25.0, 25.4, 24.8, 24.6, 26.7, 25.2,...