This function takes an xml object, created from readXml
,
and an xpath query referencing an element of the document,and returns
an R object represneting the element.
The xpath query must retrive an element, not an attribute.
xclass(doc, xpathq, prefix = character(0))
XMLInternalDocument
retrieved using
readXml
.NetAffx
-based
classes, the prefix is Affx; no prefix is required for DTT
or ARR documents.http://www.w3.org/TR/xpath provides a very useful description of xpath. Addiitonal references are in the vignette `Retrieving MAGE and ARR sample attributes'.
readXml
for appropriately reading XML documents.