R/importance.R

In jkruppa/Rjungle: Random Jungle in R

# Copyright (C) 2008-2010  Daniel F. Schwarz
# 
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# 
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#

library(methods)

if (!exists("importance"))
  importance <- function(x, ...)  UseMethod("importance")

if (!exists("importance.default"))
  importance.default <- function(x, ...)
    stop("No method implemented for this class of object")

##' Reads importance information from the files produced by the
##' \code{\link{rjungle}} function.
##'
##' to add
##' @title importance
##' @param x An object of class \code{rjungle}.
##' @param ... 
##' @return A \code{data.frame}. If \code{\link{rjungle}} was called with
##' \code{imp=2},  rows represent the input variables ordered by index and
##' columns contain  Gini index as well as Raw-, Breiman-, Liaw- and
##' Meng-Score, SDs for the  Breiman- and Meng-Score, variable names
##' and the number of trees in which the  according variable was used
##' for splitting.
##' @references \url{www.randomjungle.de}
##' @author Daniel Schwarz with modifications by Andreas Bender
##' and Jochen Kruppa
##' @seealso \code{\link{rjungle}}, \code{\link{confusion}}
##' @keywords importance
##' @S3method importance rjungle
##' @export importance importance.rjungle

importance.rjungle <- function(x, ...) {
  rj = x
  
  if (!inherits(rj, "rjungle"))
    stop("data argument should be rjungle-class")
  
	if (rj@importance == 1){  
		fileName = paste(rj@tmpFile, ".importance", sep = "")
	  if (!file.exists(fileName)) stop(paste("no importance file exists.", fileName))
		imp<-read.table(fileName, header=TRUE)
    imp<-imp[order(imp$id),] 
  }
	else{
    fileName = paste(rj@tmpFile, '.importance', sep='')
    if(!file.exists(fileName)) stop(paste('no importance file exists.',fileName))
		fileName2 = paste(rj@tmpFile, ".importance2", sep = "")
    if (!file.exists(fileName2)) stop(paste("no importance file exists.", fileName2))
    imp1<-read.table(fileName, header = TRUE)
    imp2<-read.table(fileName2, header = TRUE)
    imp<-cbind(imp1[order(imp1$id),], imp2[order(imp2$id),5:11])
  } 
  return(imp)
}