Displaying 20 results from an estimated 7000 matches similar to: "lmer coefficient distributions and p values"
2007 Oct 26
1
2-way Factorial with random factors
Hello:
I am using R mainly on windows XP, version 2.5. I?m a biologist,
with a medium level statistics background. I have a problem stating a
two-way factorial design where both factors are random. I?m using the
lmer() function implemented in the Matrix package version 0.99.
My design is as follows: Two species were randomly selected from a
total of 4 species. This species are present
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 Oct 16
2
Bootstrapping Contrasts for Repeated Measures ANOVA
I have executed a Repeated Measures ANOVA with one DV (latency) and
one within subject factor (acoustic condtion: 3 levels) by
bootstrapping my sampling distribution of F from the empirical sample
distribution. I chose to resample because the sample distribution
deviates from normality a lot.
The overall F is significant and now I wish to decompose this with
contrasts to ask if latencies to
2007 Oct 16
1
Calculating confidence in an estimate including number of trials?
[Yes, this is related to a homework problem, but is not the problems
itself.]
In my mathematical statistics class, we've just learned about properties
of estimators, and I can now solve manually problems like this:
A sample of size n = 16 is drawn from a normal distribution where sigma
= 10 but mu is unknown. If mu = 20, what is the probability that the
estimator mu hat = Y bar will lie
2007 Aug 23
1
Clarification: Expedite scalar f(x) evaluation over vectors
Please note clarifications in <<>> below. My apologies for any confusion.
Thanks again,
Scott
---------- Forwarded message ----------
From: Scott Stark <stark.sc@gmail.com>
Date: Aug 23, 2007 1:03 PM
Subject: Expedite scalar f(x) evaluation over vectors
To: r-help@lists.r-project.org
Dear R community,
I am trying to code a fairly complex equation for optim(). My current
2007 Sep 07
2
Matlab's lsqnonlin
Hi! I'm translating some code from Matlab to R and I found a problem.
I need to translate Matlab's function 'lsqnonlin'
(http://www-ccs.ucsd.edu/matlab/toolbox/optim/lsqnonlin.html) into R,
and at the beginning I thought it would be the same as R's 'optim'. But
then I looked at the definition of 'lsqnonlin' and I don't quite see how
to make
2023 Apr 13
3
Is LDAP + Kerberos without Active Directory no longer supported?
I have a server that runs stand-alone with an LDAP directory and a KDC .
The linux machines have sssd to allow unified users etc. The clients are
mostly MacOS and Windows machines that aren't part of an AD.
This config has worked for 15 years, but after upgrading Debian and
bringing in Samba Version 4.17.7-Debian it seems to be broken.
I believe this is related to:
2007 Aug 29
3
OT: distribution of a pathological random variate
Folks,
I wonder if anything could be said about the distribution of a random variate x, where
x = N(0,1)/N(0,1)
Obviously x is pathological because it could be 0/0. If we exclude this point, so the set is {x/(0/0)}, does x have a well defined distribution? or does it exist a distribution that approximates x.
(The case could be generalized of course to N(mu1, sigma1)/N(mu2, sigma2) and one
2007 Aug 17
2
image plot with multiple x values
Hi,
New to R, I don't find a way to plot the following data with image():
x is a N * M matrix
y is a vector of length M
z is a N*M matrix
I wish to plot z as a greyscale image, but my x axis is different for
every row of the z data.
Here is a minimal example,
> theta<-c(3:6) # N
> y<-c(1:5) # M
>
> x<-theta%*%t(y)# N * M
> z<-sin(x) # N * M
>
> image(z)
2007 Oct 17
3
Multi-objective optimization
Dear All,
Is there any package to do multi-objective optimization? For instance,
consider the following problem:
maximize f(x,y) in order to x
and
maximize g(x,y) in order to y,
simultaneously, with x and y being the same both for f and g. Can R do
it numerically?
Thanks in advance,
Paul
2007 Oct 31
3
Homework help: Is this how CIs of normal distributions are computed?
I'm looking for a function in R similar to t.test() which was generously
pointed out to me yesterday, but which can be used for normally
distributed data.
To recap yesterday:
> x <- scan()
1: 62 52 68 23 34 45 27 42 83 56 40
12:
Read 11 items
> alpha<- .05
> t.test(x)
One Sample t-test
data: x
t = 8.8696, df = 10, p-value = 4.717e-06
alternative hypothesis: true
2007 Aug 07
1
lmer() : crossed-random-effects specification
Dear all,
I want to estimate a crossed-random-effects model (i.e., measurements,
students, schools) where students migrate between schools over time.
I'm interested in the fixed effects of "SES", "age" and their
interaction on "read" (reading achievement) while accounting for the
sample design. Based on a previous post, I'm specifying my model as:
fm1 <-
2007 Jan 25
1
New version of lme4 and new mailing list R-SIG-mixed-models
Version 0.9975-11 of the lme4 package has been uploaded to CRAN. The
source package should be available on the mirrors in a day or two and
binary packages should follow soon after.
There are several changes in this release of the package. The most
important is the availability of a development version of lmer called,
for the time being, lmer2. At present lmer2 only fits linear mixed
models.
2007 Jan 25
1
New version of lme4 and new mailing list R-SIG-mixed-models
Version 0.9975-11 of the lme4 package has been uploaded to CRAN. The
source package should be available on the mirrors in a day or two and
binary packages should follow soon after.
There are several changes in this release of the package. The most
important is the availability of a development version of lmer called,
for the time being, lmer2. At present lmer2 only fits linear mixed
models.
2007 Aug 31
2
size limitations in R
I am a SAS user currently evaluating R as a possible addition or even
replacement for SAS. The difficulty I have come across
straight away is R's apparent difficulty in handling relatively large data
files. Whilst I would not expect it to handle
datasets with millions of records, I still really need to be able to work
with dataset with 100,000+ records and 100+
variables. Yet, when reading
2008 Mar 13
1
lmer and correlation
Hello list,
I've been reading through the archives and it seems as though, as
of right now, there is no way to specify the correlation structure in
lmer. I was wondering if anyone knows if this is going to be
implemented? I'm using mixed-effects models within a tree structure,
so I make a lot of calls to lme to get the resulting deviance, and
lmer2 is almost 5 times faster than lme
2007 Sep 13
2
beginner's questions ... sorry
I have 316 files. Each file represents a patient's breathing track
(respiratory signal recorded for a variable number of cycles). All files
have the same are made up of a header followed by a variable number of
records.
Each record contains 7 comma separated fields.
The patient ID is recorder in the header which is stripped off when reading
the file into a R data.frame.
Since I need to keep
2009 Dec 11
1
Notification of false convergence with lmer()
I am running the lmer() command in a for loop and occasionally a particular
iteration is producing the false convergence warning. I would like to be
able to mark these iterations with a dummy variable, but I can't find any
other notification besides the warning message, which, in a for loop, only
is printed after the loop is finished (which does not allow me to see which
iteration it happened
2007 Sep 28
6
Graphics and LaTeX documents with the same font
Dear All,
I know how to export graphics as pdf files and then how to include
them in LaTeX documents. However, I do not know how to do in order to
have the text of the graphics written with the font selected for the
LaTeX document. Is that possible?
Thanks in advance,
Paul
2012 Oct 05
1
Error in lmer: asMethod(object) : matrix is not symmetric [1, 2]
Dear R Users,
I am having trouble with lmer. I am looking at recombinant versus non
recombinant individuals. In the response variable recombinant
individuals are coded as 1's and non-recombinant as 0's. I built a model
with 2 fixed factors and 1 random effect. Sex (males/females) is the
first fixed effect and sexual genotype (XY, YY, WX and WY) the second
one. Sexual Genotype is