search for: murtaugh

...(rowsum(Number,Gene_Name)), rowsum(Number,Gene_Name)) but then I have to manually replace the row names of the dataframe with numbers, to get back to what I wanted in the first place. I hope this makes some sort of sense. Is there an easier way to do this? Thanks in advance! Charlie Murtaugh ===== L. Charles Murtaugh Assistant Professor University of Utah Dept. of Human Genetics 15 N. 2030 E. Rm. 2100 Salt Lake City, UT 84112 tel 801-581-5958 fax 801-581-6463 email murtaugh@genetics.utah.edu [[alternative HTML version deleted]]

Hi, I'm running simulations that include a function that occasionally fails because of an unpredictable singularity in a matrix that it tries to invert. I'd like to have the function return 'NA' when that happens, so that the simulations can continue. I've tried things like: test <- function() { options(error=return(NA)) x <- solve(0) return(x) }

Dear list, I wanna select the significant variables relative to bird distribution, using stepwise method. However, the result is always the best-fit model. Please kindly suggest if it is possible to show the selection process. Thank you Elaine [[alternative HTML version deleted]]

Hi, I often work from home, running R on my office computer and displaying interactive graphics on my home computer using X11. This was always more sluggish than sitting at my office computer, obviously, but recently the graphics transfer has become painfully slow -- so slow, that I now divert the images to a postscript file and display that file remotely (which takes a second or two). I

Dear members of the R help list, I want to do a hierarchical glm with binomial family but am unsure about how to write the syntax which involves nesting. I want to test whether the risk of being attacked by Herbivores for Meadowsweet plants is significantly dependent on the Distance to heterospecific source plants. Dependent variable = Herbivory (yes/no) Explanatory continuous variable =

I'm trying to install R under Ubuntu 7.10 (gutsy; Linux 2.6.22-15-generic x86_64). Following the instructions at http://cran.r-project.org/bin/linux/ubuntu/README, I installed r-base, r-base-core, and r-base-dev without any problems. When I open R, however, I get the message "Can't open /usr/lib64/R/etc/ldpaths". That file is linked to /etc/R/ldpaths, which doesn't exist

...it's not clear whether covariates (distances to heterospecific plants) differ within subpopulations or populations.   If they don't differ with subpopulations, I would (strongly) recommend aggregating the values within subpopulations and analyzing proportions as a regression analysis: see Murtaugh, Paul A. ?SIMPLICITY AND COMPLEXITY IN ECOLOGICAL DATA ANALYSIS..? Ecology 88, no. 1 (2007): 56-62.   If they do, then your design is model<-glmer(Herbivory~Distance+(1|Population/Subpopulation), family=binomial)   See also: https://stat.ethz.ch/pipermail/r-sig-mixed-models/2009q2/002320.htm...

The function 'regsubsets' appears to calculate a BIC value that is different from that returned by the function 'BIC'. The latter is explained in the documentation, but I can't find an expression for the statistic returned by 'regsubsets'. Incidentally, both of these differ from the BIC that is given in Ramsey and Schafer's, The Statistical Sleuth. I assume