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As economists would say, there are significant start-up costs to learning R. It can be daunting. Resources exist, however, to smooth the transition. Here is a PDF, if you'd like a document to get started. (Be sure to check the Appendix on sources of help & documentation.) but I think that this site is even better: <http://www.statmethods.net/> where the author says
"I created this website for experienced users of popular statistical packages such as SAS, SPSS, Stata, and Systat (although current R users should also find it useful). My goal is to help you quickly access this language in your work. "
Also, there was a complaint that R had a file size limitation (based on hardware constraints) and this is no longer an issue.
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