Thanks, Rolf, Justin and Uwe! Actually I wanted to run .R file as a script, just like what people do for bash scripts or python scripts. It seems to me that adding "#!/usr/bin/R -f" at the first line is what I need. Is this true?
Li Sun 2012/1/2 Rolf Turner <rolf.tur...@xtra.co.nz>: > On 03/01/12 17:02, Li SUN wrote: >> >> Hello, >> >> I am a beginner to the R language and find it fantastic and >> well-designed, quite different from other programming languages. > > What a refreshingly sensible attitude!!! :-) > >> This is the first time I post on the r-help mailing list. >> >> In invoking the function source(filename), it seems that the filename >> has to exist in the current working directory, otherwise it has to be >> specified in full path. So is there any mechanism(such as environment >> variable) to specify an additional directory of .R files that source() >> could search in? > > > I'm no expert on this, and others may correct me, but > > (1) I don't believe any such mechanism exists. > > (2) It's probably not a good idea, even if such a mechanism > were to exist. Directories have a tree structure, rather than > being linearly ordered in the way that data bases on your > R search path are ordered. > > I believe you would run all sorts of risks of confusion and > of getting the wrong file were you to invoke such a mechanism. > > It is ``good practice'' to have separate directories associated > with different projects and to situate all files, that you might wish > to source in respect of a given project, in the directory associated > with that project. > > I know that this is an irritating sort of response --- ``No, you can't > do that, and you shouldn't do it anyway!'' --- but I sincerely believe > this to be true. > > That being said, I also believe that you could program up such a mechanism > yourself. I.e. build a function "source2()" which would have a "hard coded" > list > of directories to search, and would make use of the "try()" function. > > Might be a good exercise for you, given that you are starting out in R > and looking to upgrade your skills! :-) > > cheers, > > Rolf Turner > > ______________________________________________ R-help@r-project.org 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.
