Displaying 20 results from an estimated 1000 matches similar to: "corMatrix crashes R 2.5.1 (windows XP) with corARMA structure"
2007 Oct 10
2
corMatrix crashes with corARMA structure (PR#9952)
Full_Name: Benjamin Tyner
Version: 2.6.0 RC 2007-10-01 r43043
OS: WinXP
Submission from: (NULL) (171.161.224.10)
platform i386-pc-mingw32
arch i386
os mingw32
system i386, mingw32
status RC
major
2005 Mar 22
2
LME correlation structures: user defined
Let me modify my question about user-defined covariance structures for LME models: Can somebody tell me how I can see the code for the definition of the correlation structures that come with the NLME package. Specifically I like to see the code for the functions coef, corMatrix, and intialize for any of the pre-defined correlation structures, and use this as a template to define a new correlation
2008 Feb 12
0
nlme & special case of corARMA?
Dear All:
I am trying to fit a special case of a 2-banded Toeplitz correlation
structure. A 2-banded Toeplitz has ones on the diagonal, a
correlation, RHO1, on the first off-diagonal, and a correlation, RHO2,
on the second off-diagonal, with zeros on all subsequent
off-diagonals. After reading relevant sections in Mixed-Effects
Models in S and S-PLUS (Pinheiro & Bates, 2000) and searching
2003 Jul 08
1
Questions about corARMA
Hi,
I'm a new member here in the list. I am a graduate from University of Georgia. Recently in doing analysis using lme on a dataset, I found several questions:
1. How to express the equation when the correlation structure is very complicated. For exmaple, if the fixed is y(t)=0.03x1(t)+1.5x2(t)(I omitted "hat" and others). And the model with corARMA(p=2,q=3) is proper. What will be
2006 Nov 20
1
My own correlation structure with nlme
Dear all,
I am trying to define my own corStruct which is different from the
classical one available in nlme. The structure of this correlation is
given below.
I am wondering to know how to continue with this structure by using
specific functions (corMatrix, getCovariate, Initialize,...) in order to
get a structure like corAR1, corSymm which will be working for my data.
Thanks in advance.
2005 Dec 09
1
R-help: gls with correlation=corARMA
Dear Madams/Sirs,
Hello. I am using the gls function to specify an arma correlation during
estimation in my model. The parameter values which I am sending the
corARMA function are from a previous fit using arima. I have had some
success with the method, however in other cases I get the following error
from gls: "All parameters must be less than 1 in absolute value". None
of
2005 Apr 14
1
lme, corARMA and large data sets
I am currently trying to get a "lme" analyses running to correct for the
non-independence of residuals (using e.g. corAR1, corARMA) for a larger data
set (>10000 obs) for an independent (lgeodisE) and dependent variable
(gendis). Previous attempts using SAS failed. In addition we were told by
SAS that our data set was too large to be handled by this procedure anyway
(!!).
SAS script
2004 Jul 30
1
lme: problems with corARMA
Trying following example from Pinheiro and Bates in order to fit an
ARMA(1,1) model:
library(nlme)
fm1Ovary.lme<-lme(follicles~sin(2*pi*Time)+cos(*pi*Time),data=Ovary,random=p
dDiag(~sin(2*pi*Time)))
fm5Ovary.lme<-update(fm1Ovary.lme,corr=corARMA(p=1,q=1))
I get follwing error message:
Error in "coef<-.corARMA"(`*tmp*`, value = c(62.3428455941166,
62.3428517930051 :
2012 May 02
3
Consulta gráfica
Hola,
Por favor, ¿podríais indicarme qué recursos (librerías o ideas) pueden resultar de utilidad para crear un gráfico del estilo del de la figura 3.8 del siguiente link?
http://www.tsc.uvigo.es/BIO/Bioing/ChrLDoc3.html#3.5
Actualmente estoy utilizando funciones muy básicas y la verdad es que no me encuentro muy satisfecha con el resultado.
Muchas gracias.
Eva
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2005 Jun 10
1
Problems with corARMA
Dear all
I am tryiing to fit the following lme with an ARMA correlation structure:
test <- lme(fixed=fev1f~year, random=~1|id2, data=pheno2,
correlation=corARMA(value=0.2, form=~year|id2), na.action=na.omit)
But I get the following error message:
Error in getGroupsFormula.default(correlation, asList = TRUE) :
"Form" argument must be a formula
I have used this same form
2004 Mar 09
2
corARMA and ACF in nlme
Hi R-sters,
Just wondering what I might be doing wrong. I'm trying to fit a multiple
linear regression model, and being ever mindful about the possibilities of
autocorrelation in the errors (it's a time series), the errors appear to
follow an AR1 process (ar(ts(glsfit$residuals)) selected order 1). So,
when I go back and try to do the simultaneous regression and error fit with
gls,
2008 Feb 08
0
User specified correlation structure (e.g., 2-banded Toeplitz)
Dear All:
I am trying to fit a special case of a 2-banded Toeplitz correlation
structure. A 2-banded Toeplitz has ones on the diagonal, a
correlation, RHO1, on the first off-diagonal, and a correlation, RHO2,
on the second off-diagonal, with zeros on all subsequent
off-diagonals. After reading relevant sections in Mixed-Effects
Models in S and S-PLUS (Pinheiro & Bates, 2000) and searching
2008 Feb 08
0
User-specified correlation structure (e.g., 2-banded Toeplitz)
Dear All:
I am trying to fit a special case of a 2-banded Toeplitz correlation
structure. A 2-banded Toeplitz has ones on the diagonal, a
correlation, RHO1, on the first off-diagonal, and a correlation, RHO2,
on the second off-diagonal, with zeros on all subsequent
off-diagonals. After reading relevant sections in Mixed-Effects
Models in S and S-PLUS (Pinheiro & Bates, 2000) and searching
2003 Jul 09
0
model selection in lme when corARMA is assumed
I have a data analysis job for which lme may be used. Prof. Spencer Graves had helped me much on that. I'm really appreciated for that. Could anybody else in the list give me some hints from other perspectives? I hope I can learn as much as possible for this complicated real data.
Thanks in advance.
Hanhan
To briefly describe my data: My data is health effect measurements (y) and personal
2012 Apr 19
2
Gls function in rms package
Dear R-help,
I don't understand why Gls gives me an error when trying to fit a
model with AR(2) errors, while gls (from nlme) does not. For example:
library(nlme)
library(rms)
set.seed(1)
d <- data.frame(x = rnorm(50), y = rnorm(50))
gls(y ~ x, data=d, correlation = corARMA(p=2)) #This works
Gls(y ~ x, data=d, correlation = corARMA(p=2)) # Gives error
# Error in
2009 May 01
1
computationally singular and lack of variance parameters in SEM
Hi all,
I am trying to set up a simple path analysis in the SEM package, but I am
having some trouble. I keep getting the following error message or
something similar with my model, and I'm not sure what I'm doing wrong:
Error in solve.default(C) :
system is computationally singular: reciprocal condition number =
2.2449e-20
In addition: Warning message:
In sem.default(ram = ram, S = S,
2005 Oct 31
2
nlme error message
Dear Friends,
I am seeking for any help on an error message in lme
functions. I use mixed model to analyze a data with
compound symmetric correlation structure. But I get an
error message: "Error in corMatrix.corCompSymm(object) :
NA/NaN/Inf in foreign function call (arg 1)". If I change
the correlation structure to corAR1, then no error. I have
no clue how to solve this problem.
2006 Jan 05
1
Problem with nlme version 3.1-68
Dear All:
I updated my R program as well as associated packages yesterday. Currently
my R version is 2.2.1 running under WINXP SP-2.
When I tried to list (summary) an nlme object that I developed before, I got
the following error message:
[ Error in .C("ARMA_constCoef", as.integer(attr(object, "p")),
as.integer(attr(object, :
C entry point "ARMA_constCoef"
2010 Apr 14
1
creating a new corClass for lme()
Hi,
I have been using the function lme() of the package nlme to model grouped
data that is auto-correlated in time and in space (the data was collected on
different days via a moving monitor). I am aware that I can use the
correlation classes corCAR1 and corExp (among other options) to model the
temporal and spatial components of the auto-correlation. However, as far as
I can tell, I can only
2008 May 02
1
Errors using nlme's gls with autocorrelation
Hi,
I am trying out a generalized least squares method of forecasting that
corrects for autocorrelation. I downloaded daily stock data from Yahoo
Finance, and am trying to predict Close (n=7903). I have learned to use
date functions to extract indicator variables for Monday - Friday (and
Friday is missing in the model to prevent it from becoming full rank). When
I run the following code...