\name{xps-package} \alias{xps-package} \alias{xps} \docType{package} \title{xps Package Overview} \description{ xps Package Overview } \details{ Important data classes: \code{\link{SchemeTreeSet}}, \code{\link{DataTreeSet}}, \code{\link{ExprTreeSet}}, \code{\link{CallTreeSet}}, \code{\link{FilterTreeSet}}, \code{\link{AnalysisTreeSet}}. Full help on methods and associated functions is available from within class help pages. Additional data classes: \code{\link{ProjectInfo}}, \code{\link{PreFilter}}, \code{\link{UniFilter}}. The package handles pre-processing, normalization, filtering and analysis of Affymetrix GeneChip expression arrays, including exon array systems (Exon 1.0 ST: core, extended, full probesets), gene array systems (Gene 1.0 ST) and plate array systems on computers with 1 GB RAM only. It imports Affymetrix .CDF, .CLF, .PGF and .CEL as well as Affymetrix annotation files, and computes e.g. RMA, MAS5, FARMS, DFW, MAS5-calls, DABG-calls, I/NI-calls. It is an R wrapper to XPS (eXpression Profiling System), which is based on ROOT, an object-oriented framework developed at CERN. Thus, the prior installation of ROOT is a prerequisite for the usage of this package, see the README file. However, no knowledge of ROOT is required. ROOT is licensed under LGPL and can be downloaded from \url{http://root.cern.ch}. } \author{ Christian Stratowa \email{cstrato@aon.at} } \keyword{package}