xclass {AffyCompatible}R Documentation

(Advanced) Construct R objects from XML document queries

Description

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.

Usage

xclass(doc, xpathq, prefix = character(0))

Arguments

doc An XMLInternalDocument retrieved using readXml.
xpathq A length-1 character string representing an xpath query into the document.
prefix A prefix used to map, when necessary, between the XML class name and the corresponding R class. For NetAffx-based classes, the prefix is ‘Affx’; no prefix is required for DTT or ARR documents.

Value

An R object corresponding to the class(es) referenced by the xpath query.

Author(s)

Martin Morgan

References

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'.

See Also

The vignettes `Retrieving MAGE and ARR sample attributes' and `Annotation retrieval with NetAffxResource' for detailed illustration of use.

readXml for appropriately reading XML documents.

Examples

example(readXml)

[Package AffyCompatible version 1.0.1 Index]