R/read_tree.R

In pedroguarderas/mau: Decision Models with Multi Attribute Utility Theory

# Read decision tree -------------------------------------------------------------------------------
#' @title Evaluate utilities
#' @description Read a csv file where the decision tree is defined. 
#' @param file input csv file containing the tree.
#' @param skip starting row for read.
#' @param nrows number of rows to read.
#' @return data.table with utilities.
#' @author Pedro Guarderas, Andrés Lopez
#' @seealso \code{\link{read_utilities}}, \code{\link{make_decision_tree}}
#' @examples
#' library( data.table )
#' library( igraph )
#' file <- system.file("extdata", "tree.csv", package = "mau" )
#' sheetIndex <- 1
#' tree.data <- read_tree( file, skip = 0, nrows = 8 )
#' @importFrom utils read.csv
#' @importFrom data.table setnames as.data.table
#' @export
read_tree <- function( file, skip, nrows ) {
  
  graph <- read.csv( file, header = TRUE, sep = ",", quote = "\"'", skip = skip, nrows = nrows,
                     colClasses = c('integer','character', 'integer', 'integer', 'numeric' ),
                     stringsAsFactors = FALSE )
  
  graph <- as.data.table( graph )
  setnames( graph, 1:5, c('id','name','parent','cod','weight') )
  
  graph <- merge( graph, 
                  subset( graph, select = c( 'id','name' ) ),
                  by.x = 'parent', by.y = 'id', all.x = TRUE )
  
  setnames( graph, 1:6, c( 'parent', 'id', 'name', 'cod', 'weight', 'name.parent' ) )
  
  with( graph, {
    graph[ !is.na( cod ), funct := name ]
    graph$funct <- sapply( graph$funct, FUN = stand_string )
    
    graph <- graph[ , list( parent, id, name, cod, weight, name.parent, funct )  ]
    graph <- graph[ with( graph, order( id ) ) ]
    rownames( graph ) <- NULL
    
    return( graph )
  })
}

Read.Tree <- function( file, skip, nrows ) {
  .Deprecated(
    new = 'read_tree',
    msg = 'The function Read.Tree will be replaced by the function read_tree',
    old = 'Read.Tree' )
  return( read_tree( file, skip, nrows ) )
}