search for: rchandler

Hello, I'm trying to plot a fitted lm() line on a plot when the one explanatory variable is log transformed and log="x". I get different lines using abline and predict.lm(). #Example x <- 1:100 y <- rnorm(100) plot(y ~ x, log="x") abline(lm(y ~ log(x))) lines(x, predict(lm(y ~ log(x))), lwd=2) I'm sure I'm missing something but could someone tell me which

Hello all, Is AIC calculated incorrectly in lmer? It appears as though it uses AIC = -2*logLik - 2*#parms, instead of -2*LogLik + 2*#parms? Below is output from one of many models I have tried: Generalized linear mixed model fit using PQL Formula: cswa ~ pcov.ess1k + (1 | year) Data: ptct50.5 Family: poisson(log link) AIC BIC logLik deviance 224.8466 219.19 -114.4233 228.8466

Hello, I am new to R, and am having trouble getting the output I want from a stratified bootstrap. I didn't recieve a reply the first time I posted this question so I have tried to make it more clear. My data frame (denboot) is set up as follows: SITE cswa parea treat 1 BeanA 3 1.20 m 2 BeanBC 3 1.05 m 3 BeanD 1 0.93 m 4 BlackB 1 1.01

Hello, Is it possible to derive Pan's QIC (2001 Biometrics 57:120) from either a fitted gee() object in the gee package or from a geese() fit in the geepack package? If so, would anyone be kind enough to provide me with code to do so? I realize that QIC is part of the output from yags() but I would like to use one of the other functions. Thanks. Richard

Hi, Is there a way to provide starting values for the fixed effects in lmer()? I'd like to fit the following model, which requires starting values in the glm.fit() part of the code: lmer(dbh.sum ~ Treatment + (1|Site), nets, gaussian("log"), subset=Treatment!="sforest" & iocTreat!="forest") I tried tinkering with the code but I couldn't figure out the

Hi, I am getting the following error when using R CMD INSTALL ever since I upgraded to R-2.7.1: hhc: not found CHM compile failed: HTML Help Workshop not intalled? As indicated, the package is installed but without CHM help files. I have downloaded the latest version of Rtools and I have tried uninstalling and reinstalling HTML Help Workshop. I have also tried rebuilding the package several

Hello, I have a package that builds fine using R CMD build pkg --no-vignette, but I get the following error when running R CMD build pkg: ** building package indices ... Error in setwd(OutVignetteDir) : cannot change working directory ERROR: installing package indices failed I don't know why it can't change directories since I am running as administrator in Windows Vista. I also

Hello, I am new to R, and am having trouble running a stratified bootstrap. My data set consists of 38 study sites in which I recorded the number of bird pairs. Each site has been classified as burned or mowed and for each of these two strata I would like to determine the precision of an overall density estimate. I can run an unstratified bootstrap without problem, but when I specify the strata I

Hello, This is an (hopefully) improved question of one I posted several weeks ago. Does anyone know of a function for fitting "two-part" models? These models are designed to handle count data with so many zeroes that they can't be fit well with zero-inflated Poisson models or other 'typical' GLMs. My understanding is that they work by first fitting a binomial model to

Hi, I am trying to build a package from source for the first time. I'm using Windows XP. After R CMD INSTALL or R CMD check I get an error message that I don't understand. I've tried to follow the instrucions provided in the R Installation and Administration .pdf and the text file that comes with Rtools, but most of this is new to me and clearly I'm missing something. Here's