Sorry about that - got dropped from my attempts yesterday (see the first example below, that has the "useInternalNodes=TRUE") ...
Thanks again, Joh Duncan Temple Lang wrote: > 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. > ______________________________________________ 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.