similar to: regression methods for rare events?

Hi, this is not R technical question per se. I know there are many excellent statisticians in this list, so here my questions: I have dataset with ~1800 observations and 50 independent variables, so there are about 35 samples per variable. Is it wise to build a stable multiple logistic model with 50 independent variables? Any problem with this approach? Thanks John

Dear All, Suppose that you are trying to create a binary logistic model by trying different combinations of predictors. Has R got an automatic way of doing this, i.e., is there some way of automatically generating different tentative models and checking their corresponding AIC value? If so, could you please direct me to an example? Thanks in advance, Paul

I'm running a rare events logit model in R using the Zelig package and am getting some of the oddest error messages that I can't figure out. y = rnorm(100) x = c(rep("0",1), rep("1",99)) d = data.frame(won=x, bid=y) d mod1 <- zelig(y~x, model="relogit", data=d, tau=1/100, case.correct="prior", bias.correct=TRUE, robust=TRUE) > mod1 <-

From: Nate Studer <nate.studer@dornerworks.com> Add a utility function to update the rest of the timeslice accounting fields when updating the timeslice of the credit scheduler, so that capped CPUs behave correctly. Before this patch changing the timeslice to a value higher than the default would result in a domain not utilizing its full capacity and changing the timeslice to a value lower

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Dear all, I got an issue trying to parse excel files in parallel using XLConnect, the process hangs forever. Martin Studer, the maintainer of XLConnect kindly investigated the issue, identified rJava as a possible cause of the problem: This does not work (hangs): library(parallel) require(rJava) .jinit() res <- mclapply(1:2, function(i) {

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When using XLConnect's readWorksheet, instead of it correctly reading string and numeric columns, I receive NA's with the following message: " Error when trying to evaluate cell A2 - not implemented yet" I do not know what this means. Can anyone please assist? -- __________________________ *Barry E. King, Ph.D.* Chief Modeler Qualex Consulting Services, Inc.

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Hi, I am using Xen 4.2.3 installed on an Intel Atom with a Debian Dom0 and 3 Debian domU''s installed. I am trying to run some benchmarks using the Arinc653 scheduler. I have edited my grub options to boot with ''maxcpus=1 sched=arinc653'' options. I can boot the dom0 and verify that the scheduler is enabled. However when I xl create, the VM is created but I cannot

Is anyone in the leadership of the R-project going to contact the New York Times and clarify that the article gave remarkably short shrift to the people who designed the user interface for R, to a large extent AT&T researchers from an earlier generation? It would be the appropriate thing to do. The R team did not develop the user interface for R, the designers of the S programming language

On my default asterisk installation, *80 didn't work until I modified the source to move call pickup to *9. I wasn't sure what I was doing but *80 works now. Except I thought *80 would play some voice prompts that gave the option to add the last caller to the black list as well as other options. Instead I just get a studer dial tone after the last caller gets added to the database. When I

Hi, I am trying to construct a logistic regression model from my data (104 patients and 25 events). I build a full model consisting of five predictors with the use of penalization by rms package (lrm, pentrace etc) because of events per variable issue. Then, I tried to approximate the full model by step-down technique predicting L from all of the componet variables using ordinary least squares

Hello everybody! I have the following problem: I'd like to select a sample from a subsample in a dataset. Actually, I don't want to select it, but to create a new variable sampleNo that indicates to which sample (one or two) a case belongs to. Lets suppose I have a dataset containing 40 cases: data <- data.frame(var1=seq(1:40), var2=seq(40,1)) The first sample (n=10) I drew like

Hello, I'm a biostatistician in Toronto. I would like to know if there is anything in survival analysis developed in R for the method "Evaluating the Yield of Medical Test" (JAMA. May 14,1982--Vol 247, No.18 Frank E. Harrell, Jr,PhD; Robert M. Califf, MD; David B. Pryor, MD;Kerry L.Lee, PhD; Robert A. Rosait,MD.) Hope to hear from you and thanks Lisa Wang, MSc Project Organiser