[R] Relational Databases or XML?

Gabor Grothendieck ggrothendieck at gmail.com
Thu Apr 10 22:57:26 CEST 2008


Its avaliable on CRAN extras:

http://www.stats.ox.ac.uk/pub/RWin/bin/windows/contrib/

and can be downloaded even more easily through the Windows
package menu in R.

On Thu, Apr 10, 2008 at 4:45 PM, Doran, Harold <HDoran at air.org> wrote:
> Well, I guess it is possible with XML package on CRAN. But, it seems
> there is no windows binary (yet)
>
> > -----Original Message-----
> > From: r-help-bounces at r-project.org
>
> > [mailto:r-help-bounces at r-project.org] On Behalf Of Doran, Harold
> > Sent: Thursday, April 10, 2008 4:29 PM
> > To: Keith Alan Chamberlain; r-help at 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: r-help-bounces at r-project.org
> > > [mailto:r-help-bounces at r-project.org] On Behalf Of Keith Alan
> > > Chamberlain
> > > Sent: Thursday, April 10, 2008 4:14 PM
> > > To: r-help at 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 at 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 at 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 at 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.
>



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