search for: statistist

Reading "Modern Applied Statististics with S" and trying the corresponding examples both in the book and in ../lib/R/library/MASS/script, I'm now trying chapter 4 plotting bars with the following code on a linux box with R 1.8.1: ---------------------- library(MASS) library(lattice) options(echo=T, width=65, digits=5) lung....

...This individual will work under the direction of statisticians to organize datasets, create listings and graphs to assess the quality of the data, perform statistical tests, and create Excel spreadsheets for exploring results of the analyses. We are really targeting an S-Plus Programmer with good Statististical background If you have any interest in this position please email your resume to Christina Kinchen at Ckinchen at smithhanley.com or call 800-684-9921 ext 220. Christina Kinchen Smith Hanley Consulting Senior Recruiter Phone 800-684-9921 ext 220 Direct Line 407-548-0670 Fax 407-805-302...

Dear All, Probably it is not highly relevant question: Why do stepwise regression functions in R (step() or stepAIC()) add/delete categorical variables as a set? For example, I have a four-level factor variable d, so dummies are d1,d2,d3, as stepwise regression operates d, adding or removing, d1,d2,d3 are simultaneously added/removed. What's the concern here if operating dummies individually?

Hi. I'm going to introduce the R-package for a group of medical doctors later this week and is a little confused about there use of a test named "willcoxon-pratt" for testing if the clinical and biochemical markers has decreased significantly after the use of some drugs for a group of patients. Looking into the R-functions I would in R recommand using a matched-pairs Wilcoxon