\name{expressionByFeature} \alias{expressionByFeature} \title{ Getting expression value by feature from an ExpressionSet} \description{ This function gets the expression of a specified feature (e.g. orf, gene) from an ExpressionSet. } \usage{ expressionByFeature(eSet, fkt, method="median") } \arguments{ \item{ eSet}{ An ExpressionSet, containing the normalized expression values} \item{fkt}{ Function to convert the featureNames (e.g. affy IDs) of eSet to the required features (e.g. ORFs)} \item{method}{ If one feature (e.g. ORF) has more than one feature (e.g. affy ID) on the chip, the mean/median over the intensities is taken} } \seealso{\code{\link[base:get]{mget}}} \author{ Benedikt Zacher \email{zacher@lmb.uni-muenchen.de}} \keyword{manip}