Johannes Graumann wrote: > Thanks! > but: > > library(XML) > > xmlDoc <- xmlTreeParse("http://www.unimod.org/xml/unimod_tables.xml")
You need to xmlParse() or xmlTreeParse(url, useInternalNodes = TRUE) (which are equivalent) in order to be able to use getNodeSet(). The error you are getting is because you are using xmlTreeParse() and the result is a tree represented in R rather than internal C-level data structures on which getNodeSet() can operate. xmlParse() is faster than xmlTreeParse() and one can use XPath to query it. D. > > getNodeSet(xmlDoc,"//x:modifications_row", "x") > Error in function (classes, fdef, mtable) : > unable to find an inherited method for function "saveXML", for signature > "XMLDocument" > > ? > > Thanks, Joh > > > Duncan Temple Lang wrote: > > > > > Hi Johannes > > > > This is a common issue. The document has a default XML namespace, e.g. > > the root node is defined as > > > > <unimod xmlns="http://www.unimod.org/xmlns/schema/unimod_tables_1"...> > > ..... > > > > So you need to specify which namespace to match in the XPath expression > > in getNodeSet(). The XML package provides a "convenient" facility for > > this. You need only specify the prefix such as "x" and that will > > be bound to the default namespace. You need to specify this in > > two places - where you use it in the XPath expression and > > in the namespaces argument of getNodeSet() > > > > So > > getNodeSet(test, "//x:modifications_row", "x") > > > > gives you probably what you want. > > > > D. > > > > > > > > On 8/30/10 8:02 AM, Johannes Graumann wrote: > >> library(XML) > >>> test <- xmlTreeParse( > >>> "http://www.unimod.org/xml/unimod_tables.xml",useInternalNodes=TRUE) > >>> getNodeSet(test,"//modifications_row") > > ______________________________________________ > 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. -- "There are men who can think no deeper than a fact" - Voltaire Duncan Temple Lang dun...@wald.ucdavis.edu Department of Statistics work: (530) 752-4782 4210 Mathematical Sciences Bldg. fax: (530) 752-7099 One Shields Ave. University of California at Davis Davis, CA 95616, USA
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______________________________________________ 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.