[R] example - export a data.frame to an XML file

[zubin]

In need of exporting an XML file from R, I scrub some data in R and push 
the data into another application requiring XML.  The data set is a very 
straightforward data frame of stock prices- see below.  I know the 
package XML is the one to use, but need an example or some direction on 
where to start.  I know we need to define the schema - can this be done 
in the R XML package?

"date","UYG.Open","UYG.High","UYG.Low","UYG.Close","UYG.Volume","UYG.Adjusted"
"2007-02-01",71.32,71.34,71.32,71.34,200,69.23
"2007-02-02",72.2,72.2,72.2,72.2,200,70.06
"2007-02-05",71.76,71.76,71.76,71.76,5100,69.63
"2007-02-06",72.85,72.85,72.85,72.85,3800,70.69
"2007-02-07",72.85,72.85,72.85,72.85,0,70.69