Displaying 20 results from an estimated 700 matches similar to: "(no subject)"
2008 Aug 25
3
lmer4 and variable selection
Dear list,
I am currently working with a rather large data set on body temperature
regulation in wintering birds. My original model contains quite a few
dependent variables, but I do not (of course) wish to keep them all in my
final model. I've fitted the following model to the data:
>
2012 Jan 10
1
importing S3 methods with importFrom
In my own package, I want to use the default S3 method of the generic
function lrtest() from the lmtest package. Since I need only one
function from lmtest, I tried to use importFrom in my NAMESPACE:
importFrom(lmtest, lrtest)
However, this fails R CMD check in the examples:
Error in UseMethod("lrtest") :
no applicable method for 'lrtest' applied to an object of class
2012 Aug 03
1
Multiple Comparisons-Kruskal-Wallis-Test: kruskal{agricolae} and kruskalmc{pgirmess} don't yield the same results although they should do (?)
Hi there,
I am doing multiple comparisons for data that is not normally distributed.
For this purpose I tried both functions kruskal{agricolae} and
kruskalmc{pgirmess}. It confuses me that these functions do not yield the
same results although they are doing the same thing, don't they? Can anyone
tell my why this happens and which function I can trust?
kruskalmc() tells me that there are no
2010 Feb 17
2
extract the data that match
Hi r-users,
I would like to extract the data that match. Attached is my data:
I'm interested in matchind the value in column 'intg' with value in column 'rand_no'
> cbind(z=z,intg=dd,rand_no = rr)
z intg rand_no
[1,] 0.00 0.000 0.001
[2,] 0.01 0.000 0.002
[3,] 0.02 0.000 0.002
[4,] 0.03 0.000 0.003
[5,] 0.04 0.000 0.003
[6,]
2018 Feb 14
0
Unexpected behaviour in rms::lrtest
Hello.
One of my teaching assistants was experimenting and encountered
unexpected behaviour with the lrtest function in the rms package. It
appears that when you have a pair of non-nested models that employ an
RCS, the error checking for non-nested models appears not to work.
Here is a reproducible example.
> library(rms)
Loading required package: Hmisc
Loading required package: lattice
2006 May 06
2
How to test for significance of random effects?
Dear list members,
I'm interested in showing that within-group statistical dependence is
negligible, so I can use ordinary linear models without including random
effects. However, I can find no mention of testing a model with vs.
without random effects in either Venable & Ripley (2002) or Pinheiro and
Bates (2000). Our in-house statisticians are not familiar with this,
either,
2009 Apr 03
1
Trouble extracting graphic results from a bootstrap
Hi,
I'm trying to extract a histogram over the results from a bootstrap. However
I keep receiving the error message "Error in hist.default(boot.lrtest$ll,
breaks = "scott") : 'x' must be numeric".
The bootstrap I'm running looks like:
> boot.test <- function(data, indeces, maxit=20) {
+ y1 <- fit1+e1[indeces]
+ mod1 <- glm(y1 ~ X1-1, maxit=maxit)
+
2008 Mar 08
1
ask for help on nonlinear fitting
I have a table like the following. I want to fit Cm to Vm like this:
Cm ~ Cl+Q1*b1*38.67*exp(-b1*(Vm-Vp1)*0.03867)/(1+exp(-b1*(Vm-Vp1)*0.03867))^2+Q2*b2*38.67*exp(-b2*(Vm-Vp2)*0.03867)/(1+exp(-b2*(Vm-Vp2)*0.03867))^2
I use nls, with start=list(Q1=2e-3, b1=1, Vp1=-25, Q2=3e-3, b2=1,
Vp2=200). But I always get 'singlular gradient' error like this. But
in SigmaPlot I can get the result. How
2011 Feb 03
0
Need advises on mixed-effect model ( a concrete example)
Dear R-help members,
I'm trying to run LME model on some behavioral data and need
confirmations about what I'm doing...
Here's the story...
I have some behavioral reaction time (RT) data (participants have to
detect dome kind of auditory stimuli). the dependant variable is RT
measured in milliseconds. 61 participants were tested separated in 4 age
groups (unblanced groups,
2009 Nov 03
1
lmer and estimable
Hi everyone,
I'm using lmer and estimable (from packages lme4 and gmodels respectively) and have the disconcerting happening that when I run exactly the same code, I get different results! In checking this out by running the code 50x, it seems to be that answers may be randomly deviating around those which I get from another stats package (GenStat, using the linear mixed models functionality
2011 Mar 18
0
predict.nlme
Hi folks,
I am having trouble to plot a mixed model analysis of covariance (ANCOVA).
To do so I use the function predict in nlme but the line that is being drawn
is totally out of control!!!
here is my script (where MASS_S is dry mass and MASS_F is fresh mass):
MEN<-read.table("Mentha_lme2.txt", h=T)
attach(MEN)
lme1<-lme(log(MASS_S)~log(MASS_F)*TREAT, random=~1|INDIV)
2018 Jan 22
1
what does the within component of varcomp (ape library) output indicate?
I am trying to use varcomp to obtain the variance partitioning across
different nested levels of random effects (say x,y and z). I get the
three variance components (for each of my along with an additional one
called 'within' from varcomp output. I am using the 'scale total
variance to 1' option and though the within component is small, it
does form a part of what explains the
2017 Aug 08
0
how to extract individual values from varcomp?
Hi
try
str(varcompobject)
to see structure of this object. You can extract parts by standard R means.
Cheers
Petr
> -----Original Message-----
> From: R-help [mailto:r-help-bounces at r-project.org] On Behalf Of Sharada
> Ramadass
> Sent: Tuesday, August 8, 2017 3:33 PM
> To: r-help at r-project.org
> Subject: [R] how to extract individual values from varcomp?
>
>
2008 Mar 07
1
confused about CORREP cor.LRtest
After some struggling with the data format, non-standard in
BioConductor, I have gotten cor.balance in package CORREP to work. My
desire was to obtain maximum-likelihood p-values from the same data
object using cor.LRtest, but it appears that this function wants
something different, which I can't figure out from the documentation.
Briefly, my dataset consists of 36 samples from 12
2005 Jan 27
1
Is glm weird or am I?
Hi,
I've written a script that checks all bivariate correlations for
variables in a matrix. I'm now trying to run a logistic regression on
each pair (x,y) where y is a factor with 2 levels. I don't know how (or
whether I want) to try to fathom what's up with glm.
What I wrote is attached. Here's what I get.
*****************************************************
2006 Oct 08
2
latex and anova.lme problem
Dear R-helpers,
When I try
> anova(txtE2.lme, txtE2.lme1)
Model df AIC BIC logLik Test L.Ratio p-value
txtE2.lme 1 10 8590 8638 -4285
txtE2.lme1 2 7 8591 8624 -4288 1 vs 2 6.79 0.0789
> latex(anova(txtE2.lme, txtE2.lme1))
Error: object "n.group" not found
I don't even see n.group as one of the arguments of latex()
I checked to see
>
2012 May 14
1
Extract Variance Components
Hi,
I'm still having problems putting the variance components of my model in to
a data frame, it is a continuation of this discussion,
http://r.789695.n4.nabble.com/ANOVA-problem-td4609062.html, but now focussed
on the problem of extracting variance components. I have got my mixed
effects model now
/narrow$line<-as.factor(narrow$line)
rg.lmer <- lapply(split(narrow,
2009 Jul 14
1
How does logLik(lm(...)) find the maximum log likelihoods
Hi. Thanks for your help with my previous question (comparing two lm() models with a maximum likelihood ratio test)
I had a look at lrtest from the package lmtest as it has been suggested to me, but I am not 100% sure if that is the right thing to do ...
lrtest uses the same log likelihoods as you can extract by hand from lm() with logLik - are this the maximum log likelihoods? How does R
2005 Jul 18
1
Nested ANOVA with a random nested factor (how to use the lme function?)
Hi,
I am having trouble using the lme function to perform a nested ANOVA
with a random nested factor.
My design is as follows:
Location (n=6) (Random)
Site nested within each Location (n=12) (2 Sites nested within each
Location) (Random)
Dependent variable: sp (species abundance)
By using the aov function I can generate a nested ANOVA, however this
assumes that my nested
2006 Jan 31
1
lme in R (WinXP) vs. Splus (HP UNIX)
R2.2 for WinXP, Splus 6.2.1 for HP 9000 Series, HP-UX 11.0.
I am trying to get a handle on why the same lme( ) code gives
such different answers. My output makes me wonder if the
fact that the UNIX box is 64 bits is the reason. The estimated
random effects are identical, but the fixed effects are very
different. Here is my R code and output, with some columns
and rows deleted for space