R/means.R

In polmineR: Verbs and Nouns for Corpus Analysis

#' @include S4classes.R
NULL

#' calculate means
#' 
#' @param .Object object to work on
#' @param dim numeric, 1 or 2 whether to work on rows or columns
#' @param ... further parameters
#'  @exportMethod means
#' @rdname means-method
setGeneric("means", function(.Object, ...) standardGeneric("means"))

#' @importFrom slam row_sums col_sums
#' @rdname means-method
setMethod("means", "DocumentTermMatrix", function(.Object, dim = 1){
  if (dim == 1){
    meansVector <- tapply(.Object$v, .Object$j, mean)
    which(col_sums(.Object) != 0)
    names(meansVector) <- .Object$dimnames[["Terms"]][which(col_sums(.Object) != 0)]
  } else if (dim == 2){
    meansVector <- tapply(.Object$v, .Object$i, mean)
    names(meansVector) <- .Object$dimnames[["Documents"]][which(row_sums(.Object) != 0)]
  }
  meansVector
})