similar to: Offsets in glmmPQL?

Moi! I was helping to teach a course on mixed models this week, and we came across a problem with coding more than one random effect in lme when they aren't nested. As an example, suppose we have an experiment where we sample moths from several populations, and place the moths on different trees, and measure a trait (in this case survival of offspring, but that's less important). We

I can only assume I'm betraying my ignorance here, but this is not what I would expect. I'm getting the following from a stepwise selection (with both step and stepAIC): > step(lm(sqrt(Grids)~ SE + Edge + NH), scope=~ (Edge + SE + NH)^2) Start: AIC= 593.56 sqrt(Grids) ~ SE + Edge + NH Df Sum of Sq RSS AIC <none> 2147.0 593.6 + Edge:NH 1

Dear all, I didn't find any graphical solution in the package "mva" to plot the canonical scores from a CCA (canonical correlation analysis). Does anybody knows how to plot or has anybody already programmed : - the map of the canonical scores, - the graph of the canonical weights, - the correlation circle i.e. the canonical loadings ? Thank you for help ...

Hello from a presently sunny Helsinki! I've bee trying to repeat an analysis I did about 18 months ago (the reviewers of the paper want something adding to it). I'm using R1.5.0, but I couldn't see anything in the list of changes between this and 1.5.1 to suggest it would act any differently. The data is observational, on the changes in the population status of carabid beetles, and

Moi! I have a problem where I want to find the ML estimate of a discrete parameter. I just want a function like optim that finds the max/min value for a function. Does anyone know of such a function for R? Thanks. Bob -- Bob O'Hara Rolf Nevanlinna Institute P.O. Box 4 (Yliopistonkatu 5) FIN-00014 University of Helsinki Finland Telephone: +358-9-191 23743 Mobile: +358 50 599 0540 Fax:

I want to draw a figure with several panels of unequal size, so i thought I would try using screen(). However, I can't figure out how to define the sizes as a matrix. I've tried this: split.screen(matrix(c(0,0.5,0,0.5, 0.5,1,0.5,1), byrow=F, ncol=4)) and a couple of variants on it, but get the same error: Error in par(.split.screens[[cur.screen]]) : invalid value specified

Anybody know where I can get the Pinheiro/Bates book? I can't find a bookstore w/ stock and the publisher says they don't know when they'll have it again. Thanks. -Frank

Moi! A student here has been getting a bit irritated with some side effects of scale() (OS is Windows XP, the behaviour occurs in R 2.0.0, but not 1.7.1). The problem is that she scales a variable in a data frame, then does a regression, and tries to get some predictions for some new data. However, at this point she gets an error (see the example below). This seems to be because the

Moi! I'm trying to add a rather long label to a y-axis, and it's so long that it won't fit into one line. However, things get strange when I try and split it over 2 lines. The problem seems to be the plus/minus symbol, which means I have to use expression(). I'm using R1.6.1 on Windoze 2000. As an example: thing1 <- expression(paste("log odds of survival probability (

I assume I'm missing something obvious here... The short form of my main question is: how do I extract variance components from an lme object? The longer form (plus optional supplementary question!): I'm looking at some quantitative genetics, and want to estimate two variance components so that I can then calculate a statistic called Qst from them. So I have this: reg1 <- lme(y ~

Hi! I was trying to implement a probit model on a dichotomous outcome variable and found that the predictions were outside the (0,1) interval that one should get. I later tried it with some simulated data with a similar result. Here is a toy program I wrote and I cant figure why I should be getting such odd predictions. x1<-rnorm(1000) x2<-rnorm(1000) x3<-rnorm(1000)

The background: I'm trying to fit a Poisson-lognormal distrbutuion to some data. This is a way of modelling species abundances: N ~ Pois(lam) log(lam) ~ N(mu, sigma2) The number of individuals are Poisson distributed with an abundance drawn from a log-normal distrbution. To fit this to data, I need to integrate out lam. In principle, I can do it this way: PLN1 <- function(lam, Count,

I'm sure I'm missing something obvious here, but I can't find the solution (including in the FAQ etc.). I have a vector of names of variables like this: NRes.x.y. where x and y are numbers. I want to extract these numbers as numbers to use elsewhere. I can extract the numbers as a list of characters using strsplit(), and convert that to a data frame, e.g.:

I have a simple (!) problem. What I want to do is to create a legend with Greek letters, and substituting numbers into the legend. Like this: mu=1:3 Mean=rep(mu, each=20) plot(runif(60), rnorm(60,Mean,0.1), pch=Mean) # create a plot legend(0.6,1.7, paste("mu =", 1:3), pch=mu) but with a Greek letter mu. I think the solution has something to do with substitute() possibly along with

Apologies for this - I'm sure I'm missing something somewhere... I've got a time series with several of missing values in it that I want to torture with R. But ts doesn't like the NA's, and I can't find any documentation telling me what to do about it. Help! Bob -- Bob O'Hara Metapopulation Research Group Division of Population Biology Department of Ecology and

Dear friends, Over the past weeks, I have been asking a lot of questions about how to use R in Bayesian analysis. I am brand new to R, but I am very pleased with it. I started with winbugs but I found winbugs to be a limited software, not bad but has several limitations. By contrast, R allows the analyst to tackle any problem with a huge set of tools for any kind of analysis. I love R. In

Please consider a data frame A B C D 1 4 5 0 2 3 2 75 3 4 1 84 4 5 1 90 5 3 0 100 Is there a way to plot column B and C as barplot *and* D as line on the same graph?? R-2.0.1 powered by Mandrake 10.1 ------------------------------------------------------------------------------------------------------------------------- Landini dr. Massimiliano Tel. mob. (+39) 347 140 11 94 Tel./Fax. (+39)

Hello, can anyone tell me if R has any special function for simulating the structure of human populations? Something like the genetic algorithm? I need to simulate a sample of a population with a specific structure. Is there something on R that can help me? Thanks to everyone. __________________________________________________________

Dear all, I have several questions regarding fisher.test() in R, and I'd highly appreciate any help with it. I have a group of observations, each having people's income, and an indicator of whether selected in or out a program. I want to test the difference between income of people who are in and out. Because the distribution is far from normal, I decide to use the fisher's exact

Dear all, I have several questions regarding fisher.test() in R, and I'd highly appreciate any help with it. I have a group of observations, each having people's income, and an indicator of whether selected in or out a program. I want to test the difference between income of people who are in and out. Because the distribution is far from normal, I decide to use the fisher's exact