Delphine Fontaine wrote: > Thanks for your answer which was very helpfull. I have another question: > > I have read in this document > (http://cran.r-project.org/doc/manuals/R-intro.pdf) that most of the > programs written in R are ephemeral and that new releases are not > always compatible with previous releases. What I would like to know is > if R functions are already validated and if not, what should we do to > validate a R function ? >
In the sense in which most persons use the term 'validate', it means to show with one or more datasets that the function is capable of producing the right answer. It doesn't mean that it produces the right answer for every dataset although we hope it does. [As an aside, most errors are in the data manipulation phase, not in the analysis phase.] So I think that instead of validating functions we should spend more effort on validating analyses [and validating analysis file derivation]. Pivotal analyses can be re-done a variety of ways, in R or in separate programmable packages such as Stata. -- Frank E Harrell Jr Professor and Chair School of Medicine Department of Biostatistics Vanderbilt University ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.