similar to: useR! 2004 program online

Dear Colleagues, I've been looking for a function that can perform a tree analysis, similar to CHAID or QUEST. The key point is that in this case the variables are not binary but nominal (10 different values), so "tree" (from the tree package) won't work. Does anybody know help? Sincerely, ___________________ Markus Preisetanz Consultant Client Vela GmbH

Dear Achim, Thanks for the comment. Here is the publisher's style guideline (AGU) "Because the Internet is dynamic environment and sites may change or move, treat World Wide Web, ftp files, and electronically archived data stored at data centers other than World or National Data Centers as unpublished, i.e., in text only." http://www.agu.org/pubs/AuthorRefSheet.pdf So by this

Hello I am running R 1.8.1 on a Windows platform I am attempting to fit an ordinal logistic regression model, using the polr function, as described in Venables and Ripley. But when I try model4 <- polr(ypsxcat~committed + as.factor(sex) + as.factor(drugusey) + anycsw + as.factor(sex)*committed + as.factor(sex)*as.factor(drugusey)+as.factor(sex)*anycsw, data = duhray) I get a message

Does anyone know of research on the effects of rounding on regression? e.g., when you ask people "How often have you _______?" you are more likely to get answers like 100, 200, etc. than 98, 203, etc. I'm interested in investigating this, but don't want to reinvent the wheel. thanks Peter Peter L. Flom, PhD Assistant Director, Statistics and Data Analysis Core Center for

Hello Using R 2.2.1 on a Windows machine. Has anyone programmed the Welch test for equality of variances? I tried RSiteSearch, but this gave references to t test and oneway.test, which are not quite what I need.....I need the Welch test itself, for use in a meta-analysis (to determine if variances are equal). TIA Peter Peter L. Flom, PhD Assistant Director, Statistics and Data Analysis

Thanks for all the help on my earlier questions..... How do you plot a simple time series with unequal intervals? I have the following dateofpoll <- as.ts(c("6/1/02", "7/1/02", "10/1/02", "1/4/03", "1/25/03", "6/7/03", "7/16/03", "8/17/03", "9/4/03")) reelect <- c(51, 47, 49, 51, 49, 49, 46, 45, 40)

Sorry to keep asking elementary questions......I appreciate the help. I am trying to create a dotchart with the rows sorted according to the values, rather than the labels. When I try prof <- c('Accountant', 'Administrative assistant', 'Garment worker', 'Cook', 'Dentist', 'General practictioner', 'Graduate student', 'High level

Has anyone programmed condition indexes in R? I know that there is a function for variance inflation factors available in the car package; however, Belsley (1991) Conditioning Diagnostics (Wiley) notes that there are several weaknesses of VIFs: e.g. 1) High VIFs are sufficient but not necessary conditions for collinearity 2) VIFs don't diagnose the number of collinearities and 3) No one has

Hello, I am trying to explore the use of random forests for classification and am certain about the interpretation of the importance measurements. When having the option "importance = T" in the randomForest call, the resulting 'importance' element matrix has four columns with the following headings: 0 - mean raw importance score of variable x for class 0 (where

I tried to integrate numerically a function wich is similar to the following: > dummy <- function(x) { exp(-1*x) * dnorm(x) } > dummy(-100) [1] 0 > dummy(-1000) [1] NaN > dummy(-10000) [1] NaN If I choose the lower boundary to be too small integrate causes a segmentation fault: > library(integrate) > integrate(dummy, -100, 0)$value [1] 1.387143 > integrate(dummy, -1000,

Dear developeRs, in the last month I mentioned in several discussions on R-help that Kurt and I were working on tools for "CRAN Task Views" which should help to structure the fast-growing list of packages on CRAN. Now the first version of a package called ctv (for CRAN Task Views) is available from CRAN and also two frist drafts for such views can be seen at

We are happy to announce that the first R user conference useR! 2004 is scheduled for May 20-22 2004 and will take place at the Vienna University of Technology. The conference will focus on - giving an overview of the new features of the rapidly evolving R project, - providing a platform for R users to discuss and exchange ideas how R can be used to do statistical computations, data

We are happy to announce that the first R user conference useR! 2004 is scheduled for May 20-22 2004 and will take place at the Vienna University of Technology. The conference will focus on - giving an overview of the new features of the rapidly evolving R project, - providing a platform for R users to discuss and exchange ideas how R can be used to do statistical computations, data

Pursing my earlier question, when I tried loading Lindsey's gnlm, I got a message Loading required package: rmutil Warning message: There is no package called 'rmutil' in: library(package, character.only = TRUE, logical = TRUE, warn.conflicts = warn.conflicts, According to the R documentation http://finzi.psych.upenn.edu/R/doc/html/packages.html rmutil is in the standard

Hello I am running R 2.0.1 on Windows, I am attempting to use Frank Harrell's 'fastbw' function (from the Design library), but I get an error that the fit was not created with a Design library fitting function; yet when I go to the help for fastbw (and also look in Frank's book Regression Modeling Strategies) it appears that fastbw should work with a model created with lm.....

Hello all I have a feeling this is very simple......but I am not sure how to do it My boss has two variables, one is an average of 4 numbers, the other is an average of 3 of those numbers i.e var1 = (X1 + X2 + X3 + X4)/4 var2 = (X1 + X2 + X3)/3 all of the X variables are supposed to be measuring similar constructs not surprisingly, these are highly correlated (r = .98), the question is how

Running R 1.8.1 on a Windows machine In dotchart, I would like to shrink the labels on the tick marks (that is, the numbers) without shrinking anything else. I could not find this in either the Rhelp archives or in ?dotchart, which recmmends cex to avoid 'label overlap', but cex shrinks all the characters in the plot. Is there a way to do this? Thanks Peter Peter L. Flom, PhD

Hello again I am trying to fit an ordinal logistic model using the polr function from MASS. When I run model.loan.ordinal <- polr(loancat~age + sex + racgp + yrseduc + needlchg + gallery + sniffball + smokeball + sniffher + smokeher + nicocaine + inject + poly(year.of.int,3) + druginj + inj.years) I get an error Error in optim(start, fmin, gmin, method = "BFGS", hessian =

I'd like to thank John Fox and Chuck Cleland for their help in resovling this issue. It turned out to be something simple, but perhaps others have had similar problems In my original data frame, I had 4 categories of race/ethnicity. One of the categories (other) was very small, and not similar to any of the other three categories, so I created a new data frame deleting those people.

To the R development team; I found an unusual behavior in zoo when I upgraded to R 2.11.0 - it abruptly terminated when I performed certain operations on large zoo objects. I sent an e-mail to Achim Zeileis and he said this was a potential bug that I should report to the R development team. The details are given below in the thread below. Basically, I can crash R with this code: library(zoo)