Displaying 20 results from an estimated 20000 matches similar to: "intercept value in lme"
2005 Aug 18
1
Error messages using LMER
Dear All,
After playing with lmer for couple of days, I have to say that I am
amazed! I've been using quite some multilevel/mixed modeling packages,
lme4 is a strong candidate for the overall winner, especially for
multilevel generzlized linear models.
Now go back to my two-level poisson model with cross-classified model.
I've been testing various different model specificatios for the
2006 Mar 16
2
Using of LME function in non-replicate data
Hello all R-users!
In Jun-2005, I find the follow discussion about using
of
LME function ( in NLME library ) for fitting
non-replicate data
The thread: ANOVA vs REML approach to variance
component estimation
http://tolstoy.newcastle.edu.au/R/help/05/06/6498.html
Someone expose the follow problem:
# non-replicate data
y <- c(2.2, -1.4, -0.5, -0.3, -2.1, 1.5, 1.3, -0.3,
0.5, -1.4,
2004 Feb 05
1
Multilevel in R
Hello,
I have difficulties to deal with multilevel model. My dataset is composed
of 10910 observations, 1237 plants nested within 17 stations. The data set is not
balanced. Response variable is binary and repeated.
I tried to fit this model
model<- glmmPQL( y ~ z1.lon*lun + z2.lat*lun + z1.lon*lar + z2.lat*lar + z1.lon*sca + z2.lat*sca +z1.lon*eta + z2.lat*eta,
random = ~ lun + lar + sca
2006 Jul 25
1
how to fit with "lme" function
Hi everone,
I have a question on using lme on a mixed effects model.
The linear mixed model is in the form of:
y = bX +Zu + e
where "X" and "Z" are the matrices, "b" is the coefficient vector of fixed
effects, "u" is the coefficient vector of random effects, and e is an error
vector.
I would like to use "lme" function to fit the model and
2006 Apr 13
3
Penalized Splines as BLUPs using lmer?
Dear R-list,
I?m trying to use the lmer of the lme4 package to fit a linear mixed model
of the form
Y = Xb + Zu + e
and I can?t figure out how to control the covariance structure of u. I want
u ~ N(0,sigma^2*I).
More precisely I?m trying to smooth a curve through data using the
"Penalized Splines as BLUPs" method as described in Ruppert, Wand &
Carroll (2003).
So I have Z = [Z1
2002 Mar 27
2
Error with nls
Dear R-group members,
I use:
platform i386-pc-mingw32
arch x86
os Win32
system x86, Win32
status
major 1
minor 4.1
year 2002
month 01
day 30
language R
I try to fit a 2 compartment model. The compartments are open, connected
to each other and
2009 Sep 26
1
renaming intercept column when retrieving coeficients from lme using coef function
I am still fairly new to R and have a fairly rudimentary question. I am
trying to name a vector of coefficients retrieved from a multilevel model
using the coef function. I guess the default name is "Intercept" and I
cannot figure out how to rename it.
I have tried the using the code below to name the column of coefficients
ind.y derived from an lme model. Unfortunately, the
2005 May 25
4
mixed model
Hello all,
I have problem with setting up random effects.
I have a model:
y=x1+x2+x1*x2+z1+z1*x2
where x1, x2, x1*x2 are fixed effects
and z1, z1*x2 are random effects (crossed effects)
I use library(nlme) 'lme' function.
My question is: how I should set up random effects?
I did
lme(y~x1+x2+x1:x2, data=DATA, random=~z1+z1:x2, na.action='na.omit')
but it did not work.
2004 Apr 11
1
converting lme commands from S-PLUS to R
I'm trying to do some smoothing with lme and am having some difficulty
bringing commands over from S-PLUS to R. I have the following setup
(modified from Ngo and Wand, 2004):
set.seed(1)
x <- runif(200)
y <- sin(3*pi*x) + rnorm(200)*.4
## library(splines)
z <- ns(x, 4)
The following runs without error on S-PLUS
f <- lme(y ~ 1, random = pdIdent(~ -1 + z))
But in R I get
2007 May 29
1
rgl.postscript
Hi,
I am having an issue when creating a postscript file from RGL window. It
seems to cut off some of the axis labels. Here is the code I am using.
I created a 3D plot using RGL_0.71 with R 2.5 on Windows XP.
z1<-c(5,4,1,4.5,2,3,2,1,1)
z2<-c(6,8,7,7.5,5,3.5,4,1,1)
z3<-c(3,2,4,7,3,4.5,6,2,3)
x1<-seq(1,9)
x2<-seq(1,9)
x3<-seq(10,18)
y1<-seq(8,0)
y2<--1*y1
2009 May 21
2
Naming a random effect in lmer
Dear guRus:
I am using lmer for a mixed model that includes a random intercept for a
set of effects that have the same distribution, Normal(0, sig2b). This set
of effects is of variable size, so I am using an as.formula statement to
create the formula for lmer. For example, if the set of random effects has
dimension 8, then the lmer call is:
Zs<-
2006 Oct 22
1
Multilevel model ("lme") question
Dear list,
I'm trying to fit a multilevel (mixed-effects) model using the lme function
(package nlme) in R 2.4.0. As a mixed-effects newbie I'm neither sure about
the modeling nor the correct R syntax.
My data is structured as follows: For each subject, a quantity Y is measured
at a number (>= 2) of time points. Moreover, at time point 0 ("baseline"), a
quantity X is
2006 Jul 08
2
String mathematical function to R-function
hello
I make a subroutine that give-me a (mathematical)
function in string format.
I would like transform this string into function ( R
function ).
thanks for any tips.
cleber
#e.g.
fun_String = "-100*x1 + 0*x2 + 100*x3"
fun <- function(x1,x2,x3){
return(
############
evaluation( fun_String )
############
)
True String mathematical function :-( :-(
> nomes
[1]
2009 Nov 09
3
How to transform the Matrix into the way I want it ???
Hi, R users,
I'm trying to transform a matrix A into B (see below). Anyone knows how to
do it in R? Thanks.
Matrix A (zone to zone travel time)
zone z1 z2 z3 z1 0 2.9 4.3 z2 2.9 0 2.5 z3 4.3 2.5 0
B:
from to time z1 z1 0 z1 z2 2.9 z1 z3 4.3 z2 z1 2.9 z2 z2 0 z2 z3 2.5 z3 z1
4.3 z3 z2 2.5 z3 z3 0
The real matrix I have is much larger, with more than 2000 zones. But I
think it should
2006 Jul 24
3
standardized random effects with ranef.lme()
Using ranef() (package nlme, version 3.1-75) with an 'lme' object I can
obtain random effects for intercept and slope of a certain level (say:
1) - this corresponds to (say level 1) "residuals" in MLWin. Maybe I'm
mistaken here, but the results are identical.
However, if I try to get the standardized random effects adding the
paramter "standard=T" to the
2011 Mar 29
5
Integration with variable bounds
If this is posted elsewhere I cannot find it. I need to perform multiple
integration where some of the variables are in the bounds of the other
variables. I was trying to use R2Cuba function but cannot set the upper and
lower bounds. My code so far is :
int <- function(y){
u2 = y[1]
z2 = y[2]
u1 =y[3]
z1 = y[4]
ff <- u1*(z1-u1)*u2*(z2-u2)*exp(-0.027*(12-z2))
return(ff)
}
2008 Jun 15
1
multilevel basic lme question
Hi R users
I want to use the lme package for a multilevel analysis on the following example:
> math<-c(2, 3,2, 5, 6 ,7 , 7)
> sex<-c(1, 2, 1, 2, 2, 2, 1)
> school_A<-c(1,1,1,2,2,2,2)
> school_B<-c(10,10,10,20,20,20,20)
> mydata<-data.frame(math, sex, school_A, school_B)
> mydata
School_A and school_B are two different school characteristics, math is an
2005 Sep 29
2
how to fix the level-1 variances in lme()?
Dear all,
Edmond Ng (http://multilevel.ioe.ac.uk/softrev/reviewsplus.pdf) provides
an example to fit the mixed effects meta-analysis in Splus 6.2. The
syntax is:
lme(fixed=d~wks, data=meta, random=~1|study, weights=varFixed(~Vofd),
control=lmeControl(sigma=1))
where d is the effect size, study is the study number, Vofd is the
variance of the effect size and meta is the data frame.
2012 Aug 08
3
help, please! matrix operations inside 3 nested loops
hello, this is my script:
#1) read in data:
daten<-read.table('K:/Analysen/STRUCTURE/input_STRUCTURE_tab_excl_5_282_559.txt',
header=TRUE, sep="\t")
daten<-as.matrix(daten)
#2) create empty matrix:
indxind<-matrix(nrow=617, ncol=617)
indxind[1:20,1:19]
#3) compare cells to each other, score:
for (s in 3:34) { #walks though the matrix colum by colum, starting at
2003 Aug 15
2
Oja median
I discovered recently that the phrase "Oja median" produces no hits in
Jonathan Baron's very valuable R search engine. I found this surprising
since I've long regarded this idea as one of the more interesting notions
in the multivariate robustness literature. To begin to remedy this oversight
I wrote a bivariate version and then decided that writing a general p-variate
version