R/base-sort.R

In timeSeries: Financial Time Series Objects (Rmetrics)

#
#  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 2 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.
#
#  A copy of the GNU General Public License is available at
#  ../../COPYING


################################################################################
# FUNCTION:                 DESCRIPTION:
#  sort,timeSeries           Sorts a 'timeSeries' object in time
################################################################################


sort.timeSeries <- function (x, decreasing = FALSE, ...)
{
  # A function implemented by Diethelm Wuertz and Yohan Chalabi
  
  # Description:
  #   Time sorts a 'timeSeries' object
  
  # Arguments:
  #   x - a 'timeSeries' object.
  
  # Value:
  #   Returns a time sorted object of class 'timeSeries'.
  
  # FUNCTION:
  
  # check if really necessary to sort x
  ## NB: is.unsorted can return NA
  if (!decreasing && !isTRUE(is.unsorted(x@positions))) return(x)
  
  if (length(x@positions)>0)
    x[order(x@positions, decreasing = decreasing), ]
  else
    x
}

setMethod("sort", "timeSeries", function (x, decreasing = FALSE, ...)
    sort.timeSeries(x, decreasing = decreasing, ...))

## # until UseMethod dispatches S4 methods in 'base' functions
## sort.timeSeries <- function(x, decreasing = FALSE, ...)
##   .sort.timeSeries(x, decreasing = decreasing, ...)

################################################################################