\title{Retrieve and set data from IcaSet}
  These generic functions access and set the attributes dat stored in an object of class \code{IcaSet}.
dat(object) <- value
datByGene(object) <- value
  \item{object}{object of class \code{IcaSet}}
  \item{value}{Matrix with rows representing features or genes and columns samples.}

  \code{dat} and \code{datByGene} return a matrix containing measured values (e.g
  expression data) indexed by features and genes, respectively.
  \code{geneNames} returns the names of the genes, i.e the row names of