Displaying 20 results from an estimated 1000 matches similar to: "lme unequal random-effects variances varIdent pdMat Pinheiro Bates nlme"
2004 Jul 12
0
Where does R search when source() ?
I have found the use of save( ) and attach( ) when supported by a pair
of functions written by my colleague John Miyamoto, move( ) and rm.sv( )
quite useful in managing (1) collections of useful homebrew functions,
(2) project workspaces, and (3) "packages" under development. An .Rdata
file containing these and other handy functions together with a brief
supporting document can be
2012 Jun 06
3
problem about set operation and computation after split
hi,
I met some problems in R, plz help me.
1. How to do a intersect operation among several groups in one list, without
a loop statement? (I think It may be a list)
create data:
myData <- data.frame(product = c(1,2,3,1,2,3,1,2,2),
year=c(2009,2009,2009,2010,2010,2010,2011,2011,2011),value=c(1104,608,606,1504,508,1312,900,1100,800))
mySplit<- split(myData,myData$year)
2009 Dec 09
1
split() is slow on data.frame (PR#14123)
Please see the following code for the runtime comparison between
split() and mysplit.data.frame() (they do the same thing
semantically). mysplit.data.frame() is a fix of split() in term of
performance. Could somebody include this fix (with possible checking
for corner cases) in future version of R and let me know the inclusion
of the fix?
m=300000
n=6
k=30000
set.seed(0)
x=replicate(n,rnorm(m))
2009 Dec 09
1
split() is slow on data.frame (PR#14123)
Please see the following code for the runtime comparison between
split() and mysplit.data.frame() (they do the same thing
semantically). mysplit.data.frame() is a fix of split() in term of
performance. Could somebody include this fix (with possible checking
for corner cases) in future version of R and let me know the inclusion
of the fix?
m=300000
n=6
k=30000
set.seed(0)
x=replicate(n,rnorm(m))
2012 Mar 09
0
pdMat class in LME to mimic SAS proc mixed group option? Group-specific random slopes
I would like to be able to use lme to fit random effect models In which some but not all of the random effects are constrained to be independent. It seems as thought the pdMat options in lme are a promising avenue. However, none of the existing pdMat classes seem to allow what I want.
As a specific example, I would like to fit a random intercept/slope mixed model to longitudinal observations in
2003 Mar 04
2
How to extract R{i} from lme object?
Hi, lme() users,
Can some one tell me how to do this.
I model Orthodont with the same G for random
variables, but different R{i}'s for boys and girls, so
that I can get sigma1_square_hat for boys and
sigma2_square_hat for girls.
The model is Y{i}=X{i}beta + Z{i}b + e{i}
b ~ iid N(0,G) and e{i} ~ iid N(0,R{i}) i=1,2
orth.lme <- lme(distance ~ Sex * age, data=Orthodont,
random=~age|Subject,
2008 Oct 13
2
split data, but ensure each level of the factor is represented
Hello,
I'll use part of the iris dataset for an example of what I want to
do.
> data(iris)
> iris<-iris[1:10,1:4]
> iris
Sepal.Length Sepal.Width Petal.Length Petal.Width
1 5.1 3.5 1.4 0.2
2 4.9 3.0 1.4 0.2
3 4.7 3.2 1.3 0.2
4 4.6 3.1 1.5
2001 Jan 17
1
Pinheiro/Bates Soybean nlme failure
Dear Mixed Effect Friends,
Somehow, R(1021, Windows) seem to run differently from S Plus:
The soybean example from Pinheiro/Bates on page 290 fails
in R. (Soybean1 is Soybean with the NA and "critical" case
removed. Same procedure with full Soybean).
> fm1Soy.lis<-nlsList(weight~SSlogis(Time,Asym,xmid,scal),data=Soybean1)
> fm1Soy.nlme<-nlme(fm1Soy.lis)
Error: Singularity
2008 Jul 19
1
wroung groupedData despite reading Bates and Pinheiro 3 times
Hi everyone. I am trying to add a formula to my data using the groupedData
function.
My experiment consists of randomized block design using fruits, vegetation
and time as factors. The idea is to see if fruits, vegetation and time
explain the abundance of mice. I am using tree density as a covariate.
So I tried to fit the following structure to my data.
>
2007 Oct 12
2
Basic plot question: Figure 1.1 Pinheiro & Bates
All,
Sorry for overly simplistic question, but I can't seem to remember how to
create the basic plot shown in Figure 1.1 of Pinheiro & Bates (2004; p.4).
The y-axis delineates a factor (Rail) while the x-axis displays the
distribution of a continuous variable (time) according to each level of the
factor. Didn't see it in archives but perhaps I'm not searching on correct
key words,
2002 Jan 12
1
Question about mixed-effects models example (Pinheiro and Bates)
Hi all,
I'm trying to figure out the example about mixed models in the Pinheiro
and Bates book (Mixed-Effects Models in S and S-Plus, 2000, pp. 135-137).
One thing I don't understand is:
When I run the command
fm1Orth.lm <- lm( distance ~ age, Orthodont )
followed by
fm2Orth.lm <- update( fm1Orth.lm, formula = distance ~ Sex*age )
and then do
summary(fm2Orth.lm)
2008 Jan 29
3
on trellis.par.set/get (reproducing figures from Pinheiro & Bates)
Dear R users,
I would like to exactly reproduce a figure like the 1.5 or 1.9 or 4.13
from the book
Mixed effects models in S and S-Plus.
Not for the sake of it, but because I have my own data I would like to
plot in that fashion
(no colors)
If I write
plot(ergoStool)
I can get a good informative plot with colors, but I would like to have
a B&W one instead.
I've played a little with
2003 Nov 25
1
using pdMAT in the lme function?
Hello. I want to specify a diagonal structure for the covariance matrix
of random effects in the lme() function.
Here is the call before I specify a diagonal structure:
> fit2<-lme(Ln.rgr~I(Ln.nar-log(0.0011)),data=meta.analysis,
+ random=~1+I(Ln.nar-log(0.0011)|STUDY.CODE,na.action=na.omit)
and this works fine. Now, I want to fix the covariance between the
between-groups slopes
2005 Sep 19
1
How to mimic pdMat of lme under lmer?
Dear members,
I would like to switch from nlme to lme4 and try to translate some of my
models that worked fine with lme.
I have problems with the pdMat classes.
Below a toy dataset with a fixed effect F and a random effect R. I gave
also 2 similar lme models.
The one containing pdLogChol (lme1) is easy to translate (as it is an
explicit notation of the default model)
The more parsimonious
2007 Aug 07
0
Bug in coef<-.varIdent method (nlme package) (PR#9831)
Hello,
1. It appears that "coef<-.varIdent" method does not work properly in
some instances.
Execution error:
Error in `coef<-.varIdent`(`*tmp*`, value = c(11, 12)) :
Cannot change the length of the varIdent parameter after
initialization
occurs when "coef<-.varIdent" is applied to an initialized object of
class varIdent with some of the coefficients
2005 Nov 03
1
Fitting heteroscedastic linear models/ problems with varIdent of nlme
Hi,
I would like to fit a model for a factorial design that allows for
unequal variances in all groups. If I am not mistaken, this can be done
in lm by specifying weights.
A function intended to specify weights for unequal variance structures
is provided in the nlme library with the varIdent function. Is it
apropriate to use these weights with lm? If not, is there another
possibility to do
2010 Apr 14
3
pdMat
Alguien tiene experiencia en escribir una pdMat. Para aquellos que no lo
recuerden son las matrices de covarianzas de los efectos aleatorios que
ajusta la función lme de la librería nlme
Estas matrices tiene especial importancia en aplicaciones de genética de
poblaciones y en particular en mapeo de asociación. Pinheiro y Bates dicen
que el usuario puede crear sus propias pdMat y sugiere como
2008 Jul 26
1
Simple vector question.
I have some data that I read in via read.csv:
sales2007 <- read.csv("Total2007.dat", header=TRUE)
The data looks like:
> sales2007[1:605,]
Year DayOfYear Sku Quantity CatId Category SubCategory
1 2007 1 100091 1 10862 HOLIDAY Christmas
2 2007 1 100138 1 11160 PET COSTUMES Famous (Licensed)
3 2007
2000 Aug 30
3
family question
Dear friends. Please see the program below and answer if it does simulate a
population of 1.000.000 families, each with at max 20000 children (typical
in Denmark, you know), constructed such that each family stops having
children when more boys than girls are present ? Equal numbers of boys and
girls are got in the population, according to the simulation, is that obvious ?
ND <- NP <-
2010 Jun 18
2
varIdent error using gam function in mgcv
Hello,
As I am relatively new to the R environment this question may be either
a) Really simple to answer
b) Or I am overlooking something relatively simple.
I am trying to add a VarIdent structure to my gam model which is fitting
smoothing functions to the time variables year and month for a particular
species. When I try to add the varIdent weights to variable Month I get this
error returned.