On 03-May-05 Frank E Harrell Jr wrote: > walmir-rodrigues wrote: >> Dear Fellows, >> >> How can I do to proced a step wise regression in R, if it�s possible ? >> >> Thanks, >> >> Walmir > > Here is an easy approach that will yield results only slightly less > valid than one actually using the response variable: > > x <- data.frame(x1,x2,x3,x4,..., other potential predictors) > x[,sample(ncol(x))] > >:-) -Frank
Frank, you are a sneaky subversive! But you have given me a technical clue for a project long near to my heart (with Andy's important "random parsimony" refinement). This is to implement software-driven Clinical Trials articles, for submission to standard peer-reviewed journals. The underlying engine would be the dada-engine. For samples of what this can generate, visit http://www.elsewhere.org/cgi-bin/postmodern repeatedly (or click on the "To generate another essay, follow this link" link you will find just below the article generated; repeat ad libitum). Also at the foot of the page, you will find links to explanations of how it works. See also http://dev.null.org/dadaengine/ The basis is that articles of certain kinds have a predictable structure, and utilise terminology, phrases, sentence-structures and substantive elements drawn from typical usage, and are such that the real thing is indistiguishable from the results of sampling these elements at random, under the control of a rulebased recursive transition network automaton. Tailor-made for Clinical Trials, methinks. (Mind you, someone once did a lot of work setting up the rulebase for the PostModern Lit Crit genre which is what you get in the above samples). Best wishes, Ted. ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
