How to do it...

XML data can be read by following these steps:

1. Load the library and initialize:

> library(XML) 
> url <- "cd_catalog.xml" 

1. Parse the XML file and get the root node:

> xmldoc <- xmlParse(url) 
> rootNode <- xmlRoot(xmldoc) 
> rootNode[1] 

1. Extract the XML data:

> data <- xmlSApply(rootNode,function(x) xmlSApply(x, xmlValue)) 

1. Convert the extracted data into a data frame:

> cd.catalog <- data.frame(t(data),row.names=NULL) 

1. Verify the results:

> cd.catalog[1:2,]