Displaying 20 results from an estimated 2000 matches similar to: "model selection in lme when corARMA is assumed"
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
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 :
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
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
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
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
2007 Oct 01
1
corMatrix crashes R 2.5.1 (windows XP) with corARMA structure
R-helpers,
n <- 100
arcoefs <- c(0.8)
macoefs <- c(-0.6)
p <- length(arcoefs)
q <- length(macoefs)
require(nlme)
tmp <- corARMA(value=c(arcoefs,macoefs), form=~1, p=p, q=q)
Sigma <- corMatrix(tmp, covariate = 1:n) # results in segfault
Have I used these commands in an improper way?
Thanks
Ben
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
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,
2005 Nov 13
1
selection of missing data
Hi i'm a french medical student,
i have some data that i import from excel. My colomn of the datafram
are the localisations of metastasis. If there is a metatsasis there is
the symbol "_". i want to exclude the row without metastasis wich
represent the NA data.
so, i wrote this
mela is the data fram
mela1=ifelse(mela[,c(11:12,14:21,23,24)]=="_",1,0) # selection of the
2004 Apr 22
1
lme correlation structure error
Hi there fellow R-users,
I am trying to follow an example of modelling a serial correlation structure
in the textbook "Mixed Effects Model in S and Splus".
However, I am getting some very odd results. Here is what I am trying to
run:
library(nlme)
data(Ovary)
fm1<-lme(follicles~sin(2*pi*Time)+cos(2*pi*Time),data=Ovary,random=pdDiag(~s
in(2*pi*Time)))
### The example is fine up
2011 Mar 29
1
lme:correlationstructure AR1 and random factor
Dear helpers,
I tried these models to run in the package nlme, but allways got the same
error message...
I have a correlation in 5 sessions within a field (n=12) with ten traps in
one field.
res2a <- lme(response~x+y+z+treatment),correlation =
corARMA(form = ~ session|trapfield, p = 1, q = 0), random=~1|field,
na.action=na.omit, data=plates, method="ML")
res2a <-
2011 Jun 25
1
if you start fifa error message comes
I've installed new fifa and written in the code of the terminal had opened up to play EA Sports intro then comb a new error message in there Standt:
"In the program were difficult manager11.exe gent fault and it must be-beeendet We apologize for this unnanehmlichkeiten.
The cause may be a problem in the program or may fail to run in wine sein.sie www.appdb.winehq.org tips under the
2007 Jun 21
1
Using the object of character data type as the name of the slot
Dear all,
I have a character string object:
> chara
[1] "The name of first slot"
and a list object:
> class( try1)
[1] "list"
what I want to do is to use the chara as a slot's name of "try1".
Of course I could do it like:
> try1$"The name of first slot" <- matrix("", 3, 4)
to create a slot of 3x4 matrix with the name
2024 Aug 09
1
If loop
Thanks. Hmm. The loop is doing what it is supposed to do.
> try1<-function(joint12=FALSE,marg1=FALSE,marg2=FALSE,
+??????????????? cond12=FALSE,cond21=FALSE){
+ # ***************************************************
+ # Testing if loop
+ # ***************************************************
+ if(joint12){
+?? {print ("joint12"); cat(joint12,"\n")}
+?? {print
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 Nov 13
0
sem and "simple variables"
salutations!
i am doing some longitudinal modeling with sem and thought calculating some
"simple variables" would make my model more readable. this is the smallest
subset of my model that illustrates the resulting problem.
i have 2 observed exogenous variables (c1, d2) and 4 observed endogenous
variables (dc1, dd1, dc2, dd2). c1 is the observed state at time 1, dc1 is
the change in c
2024 Aug 09
2
If loop
OK. The fact it's in a function is making things clearer.
Are you trying to update the values of an object from within the function,
and have them available outside the function. I don't speak functional
programming articulately enough but basically
v <- 1
funA <- function() {
v <- v+1
}
funA()
cat (v)
# 1
You either return the v from the function so
funB <- function() {
2012 Feb 18
2
transforming a data frame to matrix
Hello
> orderulcount
Group.1 Group.2 Group.3 x V5
7 C L 0.0 30 C / L
19 C L 0.2 27 C / L
31 C L 0.4 15 C / L
43 C L 0.6 7 C / L
54 C L 0.8 2 C / L
10 C S 0.0 27 C / S
22 C S 0.2 10 C / S
34 C S 0.4 6 C / S
46 C S 0.6 1 C / S
1 D
2016 Jan 06
0
Cannot remove symlink with missing target
On 06/01/16 17:36, Andreas Maier wrote:
> Hi,
> I have started using symbolic links on an SMB share and find that
> symbolic links whose target no longer exists cannot be removed on the
> client side.
>
> Example, on the SMB client side in an SMB-mounted directory:
>
> 1. Create a file and a relative symlink to it:
>
> $ touch a
> $ ln -s a b
> $