similar to: Variance functions in package nlme

Hello - I am fairly new to R, (i.e., ability to create functions/write programs insignificant) and was wondering if there might be a convenient way to model the following: I want to fit a gaussian glm to grouped data, while allowing for unequal variances in each of the groups. More specifically, my data set looks something like this: ---------------- data group 1 76 1 2 82 1 3

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

I am using the latest version of R on a Windows machine and get the following error when I try to initialize a correlation structure with the function corAR1 in NLME. This example is taken from the book of Pinheiro and Bates, so it should work. What is going wrong? > library(nlme) > data(Orthodont) > cs1AR1 <- corAR1(0.8, form= ~1 | Subject) > cs1AR1 <- initialize(cs1AR1, data =

  Hola,   Por favor, ¿podríais indicarme qué recursos (librerías o ideas) pueden resultar de utilidad para crear un gráfico del estilo del de la figura 3.8 del siguiente link?   http://www.tsc.uvigo.es/BIO/Bioing/ChrLDoc3.html#3.5   Actualmente estoy utilizando funciones muy básicas y la verdad es que no me encuentro muy satisfecha con el resultado.   Muchas gracias.   Eva [[alternative HTML

Hi, I am running R2.8.1 under Linux, and I am having trouble using the variance functions in nlme My basic model was something like: model0 <- lme( log(growth) ~ light * species.group , data=data, random=~light|species ) # with 20 odd species divided in 2 groups Following the methods in Pinheiro&Bates I tried to put a variance function in the model: model1 <- update(model0,

Hi list, I want to write a general function so that it would take an lm object, extract its data element, then use the data at another R function (eg, glm). I searched R-help list, and found this would do the trick of the first part: a.lm$call$data this would return a name object but could not be recognized as a data.frameby glm. I also tried call(as.character(a.lm$call$data)) or

Dear R-users I'm considering a repeated measures experiment where two within-subject factors A (2 levels) and B (3 levels) have been measured for each of 14 subjects, S. I wish to test the effect of factor A. I know that a variance component model with random effects S, S:A, S:B and S:A:B can be fitted using aov: aov( y ~ A*B + Error(S/(A*B)) ) If there is no significant interaction, the

Dear all, I am unsure about how to specify a model in R and I thought of asking some advice to the list. I have two groups ("Group"= A, B) of subjects, with each subject undertaking a test before and after a certain treatment ("Time"= pre, post). Additionally, I want to enter the age of the subject as a covariate (the performance on the test is affected by age),

Greetings, I have a meta-analysis problem in which I have fixed effects regression coefficients (and estimated standard errors) from identical models fit to different data sets. I would like to use these results to create pooled estimated regression coefficients and estimated standard errors for these pooled coefficients. In particular, I would like to estimate the model \beta_{i} = \mu +

Dear All, I'm trying to model heteroscedasticity using a multilevel model. To do so, I make use of the nlme package and the weigths-parameter. Let's say that I hypothesize that the exam score of students (normexam) is influenced by their score on a standardized LR test (standLRT). Students are of course nested in "schools". These variables are contained in the

Hi! the script ssh-copy-id assumes, that the remote machine has a POSIX Compatible shell as login shell. So you have to write in line 41: ? ssh $1 'sh -c "umask 077; test ? instead of ? ssh $1 "umask 077; test ? Patch is appended. Greetings, Benjamin Kellermann -- GPG-Key-ID: 491A3D9C Fingerprint: D19E 04A8 8895 020A 8DF6 0092 3501 1A32 491A 3D9C http://pgpkeys.pca.dfn.de/

Hi, I have problems to save printer settings like changing the size from letter to A4. This happens for user settings and default printer settings. The settings are always resetted to default values like "letter". The system uses samba 3.4.11, I also did some tests with samba 3.5.8, but nothing changed. After downgrading to 3.3.2 everything worked as expected. I didn't change any

Hello List :-) I'm sorry that this is a bit off-topic, but I don't know where to ask this question. Is there anyone who can tell if Asterisk will be present at CeBIT this year? Kind regards Thilo -- Thilo R??ler Linup Front Pallaswiesenstrasse 203 64293 Darmstadt Tel: 06151/9067-0 Fax: 06151/9067-299 Mobil: 0151/18242584 http://www.linupfront.de E-Mail:

For all who are interested: A quick review of CeBIT 2005. :-) CeBIT was a very successfull event. Most of the time, the asterisk-booth was crowded with more people than we could talk to. We had with us a demo-installation including different IP-phones, digital and analog phones as well as a Siemens HiPATH PBX to which our Asterisk-server served as a VoIP-gateway, and many people were impressed

I believe if you add the *decoder* lookahead time to the encoder lookahead time you are already referencing, you will get the numbers that you have calculated. --John On 4/11/2012 1:00 PM, speex-dev-request at xiph.org wrote: > Message: 1 > Date: 10 Apr 2012 22:07:20 +0200 > From: Thilo K?hler<koehlerthilo at gmx.de> > Subject: [Speex-dev] Speex Codec Delay Problem > To:

Hi, I am using CIFS 2.01.01 on HPUX11V2. CIFS is running in ADS security-mode. Winbind is used to map the userers from the W2K3-Domain (german) to an tdb-file. The user mapping works fine, but I have problems with the ACLS: setting the ACLS to a file or folder from windows leads in "access denied". I'm the owner of the object and have full access. The really crazy thing is,

Dear R Users, Is it possible to make file names dependent on a changing variable? For instance. I generate random numbers in a loop and at each iteration I want data to write to file (I do not want to write everything in one file using 'append'): for (i in 1:50){ x<-matrix(runif(100, min=0,max=1),nrow=5,ncol=20) Write(t(x),file="Data_i.txt",ncolumns=5,sep="\t") }

Works perfectly. Thank you. -Hugh Rand -----Original Message----- From: Spencer Graves [mailto:spencer.graves at pdf.com] Sent: Sunday, January 15, 2006 6:41 PM To: Rand, Hugh Cc: 'r-help at lists.R-project.org' Subject: Re: [R] trouble with extraction/interpretation of variance structure para meters from a model built using gnls and varConstPower How about this: >

Hi there, I just wanted to point out that Asterisk will be present at CeBit this year. We gathered some money from sponsors and were able to afford a booth together with a training-company. We'd be happy to find others joining us at the booth somewhere between 10th and 16th of March in Hannover, Germany :-) Kind regards ... -- Thilo R??ler Linup Front Pallaswiesenstrasse 203 64293

I have been using gnls with the weights argument (and varConstPower) to specify a variance structure for curve fits. In attempting to extract the parameters for the variance model I am seeing results I don't understand. When I simply display the model (or use "summary" on the model), I get what seem like reasonable values for both "power" and "const". When I