Hi Rob doc = xmlParse("url for document")
dn = getNodeSet(doc, "//descriptorna...@majortopic = 'Y']") will do what you want, I believe. XPath - a language for expressing such queries - is quite simple and based on a few simple primitive concepts from which one can create complex compound queries. The //DescriptorName is a node test. The [] is a predicate that includes/discards some of the resulting nodes. D. On 9/8/10 9:09 AM, Rob James wrote: > I am looking for the syntax to capture XML tags marked with > /DescriptorName MajorTopicYN="Y"/ , but the combination of the internal > space (between "Name" and "Major" and the embedded quote marks are > defeating me. I can get all the "DescriptorName" tags, but these include > both MajroTopicYN = "Y" and "N" variants. Any suggestions? > > Thanks in advance. > > Prototype text from PUBMED > > <MeshHeadingList> > <MeshHeading> > <DescriptorName MajorTopicYN="Y">Antibodies, Monoclonal</DescriptorName> > </MeshHeading> > <MeshHeading> > <DescriptorName MajorTopicYN="N">Blood Platelets</DescriptorName> > <QualifierName MajorTopicYN="N">immunology</QualifierName> > <QualifierName MajorTopicYN="Y">physiology</QualifierName> > <QualifierName MajorTopicYN="N">ultrastructure</QualifierName> > </MeshHeading> > </MeshHeadingList> > > > > [[alternative HTML version deleted]] > > ______________________________________________ > 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.