On Thu, 10 Apr 2008, Doran, Harold wrote: > Well, I guess it is possible with XML package on CRAN. But, it seems > there is no windows binary (yet)
There certainly is -- did you try installing it from CRAN (extras)? >> -----Original Message----- >> From: [EMAIL PROTECTED] >> [mailto:[EMAIL PROTECTED] On Behalf Of Doran, Harold >> Sent: Thursday, April 10, 2008 4:29 PM >> To: Keith Alan Chamberlain; r-help@r-project.org >> Subject: Re: [R] Relational Databases or XML? >> >> I'm not sure it is possible to parse an XML file in R >> directly. Well, I guess it's *possible*, but may not be the >> best way to do it. ElementTree in Python is an easy-to-use >> parser that you might use to first parse your XML file (or >> others hierarchically structured data), organize it anyway >> you want, and then bring those data into R for subsequent analysis. >> >> In fact, I have recently done just this. I have another >> statistical program that outputs data as an XML file. So, I >> wrote a python program that parses that XML file, pulls out >> the data of interest into a text file, and then I bring those >> data into R for analysis. >> >>> -----Original Message----- >>> From: [EMAIL PROTECTED] >>> [mailto:[EMAIL PROTECTED] On Behalf Of Keith Alan >>> Chamberlain >>> Sent: Thursday, April 10, 2008 4:14 PM >>> To: r-help@r-project.org >>> Subject: [R] Relational Databases or XML? >>> >>> Dear R-Help, >>> >>> I am working on a paper in an R course for large file support in R >>> using scan(), relational databases, and XML. I have never >> used SQL or >>> heirarchical document formats such as XML (except where it occurs >>> without user interaction), and knowledge in RDBs and XML is >> lacking in >>> my program. I have tried finding a working example for the >>> novices-novice on the topic, read many postings, the r-data >> I/O manual >>> several times, and descriptions of packages RODBC, DBI, XML, among >>> others. I understand that RDBs are (assumed at least) used widely >>> among the R community. I have not been able to put all of >> the pieces >>> together, but assuming that RDB use is actually quite >> widespread, it >>> should be quite easy to fill me in and/or correct my understanding >>> where necessary. >>> >>> For a cross-platform solution (PC/OSX at least, or in part) my >>> questions/problems are about what preliminary steps are >> needed to get >>> an SQL or XML query "to work" in R to begin with, what the >> appropriate >>> data-file formats are, and how to convert to them if >> starting out with >>> data in, say, a delimited ASCII text file. Very basic >> examples should >>> suffice, say, a table with 20 random observations, a >> grouping variable >>> with 2 levels, and a factor with 2 levels. >>> >>> ## untested code >>> set.seed(1024) >>> write.table("junk.txt", >>> data.frame(Subj=c(rep(1,10),rep(2,10)),block=rep(c(rep(-1,5),r >>> ep(1,5)),2), obs=rnorm(20,0,1))) >>> >>> Specifically, >>> >>> 1- what are the minimum required non R components that are >> needed to >>> support SQL or XML functionality, which may or may not need to be >>> installed? >>> >>> 2- what R packages need to be installed, at a minimum (also as a >>> cross-PC/Mac solution if possible or at least as much as >>> possible) >>> >>> 3- I keep seeing reference to connections of a given name "if >>> previously setup". What kind of setup is needed outside of >> R, if any? >>> >>> 4- what steps are needed in R to then connect to a file and >> import a >>> subset based on a query? >>> >>> 5- Do I then use standard R routines (e.g. write()) to >> export as a DB, >>> or an RDB/XML specific function? >>> >>> Sincerely, >>> KeithC. [U.S] >>> >>> 1/k^c >>> >>> ______________________________________________ >>> 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. >>> >> >> ______________________________________________ >> 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. >> > > ______________________________________________ > 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. > -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ 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.
