Displaying 20 results from an estimated 90 matches similar to: "Interaction term in lmer"
2006 Jun 26
0
sortables and accept question
i did some searching through the archives and didn''t really find an
answer to my question, so i''m going to just ask it.
i have a situation where there are 3 sortable lists. list1, list2,
and list3 i need list2 to accept divs from all 3 lists, but list1 and
list3 to only accept divs from the list1 and list3 i''ve added two
classes to the divs in my sortables: .rail
2010 Aug 31
4
pasting together 2 character arrays
If possible I would like to combine two different character arrays in combinations
Array1 <- c("height","weight","age","sex")
Array2 <- c("trt0","trt1","trt2")
I would like to combine these two character vectors to end up with such ...
Array3
"height.trt0.trt1"
"height.trt0.trt2"
2004 Aug 02
4
Standard errors from glm
Kia ora list members:
I'm having a little difficulty getting the correct standard errors from a glm.object (R 1.9.0 under Windows XP 5.1). predict() will gives standard errors of the predicted values, but I am wanting the standard errors of the mean.
To clarify:
Assume I have a 4x3x2 factorial with 2 complete replications (i.e. 48 observations, I've appended a dummy set of data at the
2005 Nov 03
4
nlme questions
Dear R users;
Ive got two questions concerning nlme library 3.1-65 (running on R 2.2.0 /
Win XP Pro). The first one is related to augPred function. Ive been working
with a nonlinear mixed model with no problems so far. However, when the
parameters of the model are specified in terms of some other covariates,
say treatment (i.e. phi1~trt1+trt2, etc) the augPred function give me the
following
2012 Sep 07
2
metafor package: study level variation
Hello. A quick question about incorporating variation due to study in the metafor package. I'm working with a particular data set for meta-analysis where some studies have multiple measurements. Others do not. So, let's say the effect I'm looking at is response to two different kinds of drug treatment - let's call their effect sizes T1 and T2. Some studies have multiple
2013 Sep 13
1
Creating dummy vars with contrasts - why does the returned identity matrix contain all levels (and not n-1 levels) ?
Hello,
I have a problem with creating an identity matrix for glmnet by using the
contrasts function.
I have a factor with 4 levels.
When I create dummy variables I think there should be n-1 variables (in this
case 3) - so that the contrasts would be against the baseline level.
This is also what is written in the help file for 'contrasts'.
The problem is that the function
2012 Jan 13
1
plotting regression line in with lattice
#Dear All,
#I'm having a bit of a trouble here, please help me...
#I have this data
set.seed(4)
mydata <- data.frame(var = rnorm(100),
temp = rnorm(100),
subj = as.factor(rep(c(1:10),5)),
trt = rep(c("A","B"), 50))
#and this model that fits them
lm <- lm(var ~ temp * subj, data = mydata)
#i want to
2005 Dec 08
1
Operations on a list
Hello, Everyone,
I am sorry that my message got truncated.
I resend it again as below:
Hello, R Users,
I have a list (say listexp) of 10,000 elements, each of which consists of a
matrix (5X6). It likes:
$"a"
trt1rep1 trt1rep2 trt2rep1 trt2rep2 ctlrep1 ctlrep2
[1,] 50 54 98 89 40 45
[2,] 60 65 76 79
2007 Mar 02
1
Mitools and lmer
Hey there
I am estimating a multilevel model using lmer. I have 5 imputed datasets so
I am using mitools to pool the estimates from the 5
>
> datasets. Everything seems to work until I try to use
> MIcombine to produced pooled estimates. Does anyone have any suggestions? The betas and the standard errors were extracted with no problem so everything seems to work smoothly up until
2007 Sep 15
1
Cannot get contrasts to work with aov.
I have been trying for hours now to perform an orthogonal contrast through an
ANOVA in R.
I have done a two-factor factorial experiment, each factor having three
levels. I converted this dataset to a dataframe with one factor with nine
treatments, as I couldn't work out what else to do.
I have set up a matrix with the eight orthogonal contrasts that I wish to
perform, but despite
2004 Jan 21
0
intervals in lme() and ill-defined models
There has been some recent discussion on this list about the value of using
intervals with lme() to check for whether a model is ill-defined. My
question is, what else can drive very large confidence intervals for the
variance components (or cause the error message "Error in
intervals.lme(Object) : Cannot get confidence intervals on var-cov
components: Non-positive definite approximate
2009 May 18
2
Overdispersion using repeated measures lmer
Dear All
I am trying to do a repeated measures analysis using lmer and have a number
of issues. I have non-orthogonal, unbalanced data. Count data was obtained
over 10 months for three treatments, which were arranged into 6 blocks.
Treatment is not nested in Block but crossed, as I originally designed an
orthogonal, balanced experiment but subsequently lost a treatment from 2
blocks. My
2004 Dec 01
2
unbalanced design
Hi all,
I'm new to R and have the following problem:
I have a 2 factor design (a has 2 levels, b has 3 levels). I have an
object kidney.aov which is an aov(y ~ a*b), and when I ask for
model.tables(kidney.avo, se=T) I get the following message along with
the table of effects:
Design is unbalanced - use se.contrast() for se's
but the design is NOT unbalanced... each fator level
2009 Apr 29
3
2 way ANOVA with possible pseudoreplication
Hi,
I have an experiment with 2 independant factors which I have been trying to
analyse in R. The problem is that there are several data points recorded on
the same animal. However, no combination of treatments is repeated on the
same animal. All possible combinations of treatments are done in a random
order with as many points as possible being done on 1 animal before moving
onto the next.
The
2007 Mar 14
1
How to transform matrices to ANOVA input datasets?
Hello, R experts,
I have a list called dataHP which has 30 elements (m1, m2, ..., m30).
Each element is a 7x6 matrix holding yield data from two factors
experimental design, with treatment in column, position in row. For
instance, the element 20 is:
dataHP[[20]]
col1 col2 col3 trt1 trt2 trt3
[1,] 22.0 20.3 29.7 63.3 78.5 76.4
[2,]
2009 Jan 28
1
stack data sets
Hi All,
I'm generating 10 different data sets with 1 and 0 in a matrix form and writing the output in separate files. Now I need to stack all these data sets in one vector and I know that stack only operates on list or data frame however I got these data sets by converting list to a matrix so can't go backwards now. Is there a way i can still use Stack?
Please see the program:
2004 Aug 27
3
reorder [stats] and reorder.factor [lattice]
It was recently pointed out on the lists that the S-PLUS Trellis suite has
a function called reorder.factor that's useful in getting useful ordering
of factors for graphs. I happily went ahead and implemented it, but it
turns out that R (not S-PLUS) has a generic called reorder (with a method
for "dendrogram"). Naturally, this causes R to think I'm defining a
method for
2007 May 31
0
Using MIcombine for coxph fits
R-helpers:
I am using R 2.5 on Windows XP, packages all up to date. I have run
into an issue with the MIcombine function of the mitools package that I
hoped some of you might be able to help with. I will work through a
reproducible example to demonstrate the issue.
First, make a dataset from the pbc dataset in the survival package
---------------
# Make a dataset
library(survival)
d <-
2001 Dec 03
3
beginner's questions about lme, fixed and random effects
I'm trying to understand better the differences between fixed and
random effects by running very simple examples in the nlme
package. My first attempt was to try doing a t-test in lme.
This is very similar to the Rail example that comes with nlme,
but it has two groups instead of five.
So I try
a1 <- 1:10
a2 <- 7:16
t.test(a2,a1)
getting t(18)=4.43, p=.0003224. Then I try to do it
2004 Oct 29
1
fitting linear mixed model for incomplete block design
Dear R developers and users:
I have the following data, x is the response vaiable, nsample(individual) nested within trt, and subsample nested within nsample, I want to fit trt as fixed effect, and block, nsample(trt) as random effects using lme, is the following coding correct?
dat$vgrp <- getGroups(dat, form = ~ 1|trt/nsample, level = 2)
ge.lme1 <- lme(fixed=x~trt, data=dat,