# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Library General Public
# License as published by the Free Software Foundation; either
# version 2 of the License, or (at your option) any later version.
#
# This library 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 Library General Public License for more details.
#
# You should have received a copy of the GNU Library General 
# Public License along with this library; if not, write to the 
# Free Foundation, Inc., 59 Temple Place, Suite 330, Boston, 
# MA  02111-1307  USA

# Copyrights (C)
# for this R-port: 
#   1999 - Diethelm Wuertz, GPL
#   2007 - Rmetrics Foundation, GPL
#   Diethelm Wuertz <wuertz@phys.ethz.ch>
#   www.rmetrics.org
# for the code accessed (or partly included) from other R-ports:
#   see R's copyright and license files
# for the code accessed (or partly included) from contributed R-ports
# and other sources
#   see Rmetrics's copyright file


################################################################################
# MEHODS:                   DESCRIPTION:
#  window.timeDate           Extracts a piece from a 'timeDate' object
#  cut.timeDate              Extracts a piece from a 'timeDate' object
################################################################################


window.timeDate <- 
    function(x, start, end, ...)
{   
    # A function implemented by Diethelm Wuertz
    
    # Descriptions:
    #   Subsets a timeDate object between from and to dates. 
 
    # Arguments
    #   x - an object of class "timeDate"
    #   start, end - start and end dates as "timeDate" objects.
    
    # Note:
    #   This is synonome for the function window() which should 
    #   be preferred.
    
    # FUNCTION:
    
    # Extract Subset:
    X = timeDate(x, zone = x@FinCenter, FinCenter = "GMT")
    FROM = timeDate(start, zone = x@FinCenter, FinCenter = "GMT")
    TO = timeDate(end, zone = x@FinCenter, FinCenter = "GMT")
    test = (X >= FROM & X <= TO)
    ans = timeDate(X[test], zone = "GMT", FinCenter = x@FinCenter)
    
    # Return Value:
    ans
}


# ------------------------------------------------------------------------------


cut.timeDate <-  
    function(x, from , to, ...)
{   
    # A function implemented by Diethelm Wuertz
    
    # Descriptions:
    #   Subsets a timeDate object between from and to dates. 
 
    # Arguments
    #   x - an object of class "timeDate"
    #   from, to - start and end dates as "timeDate" objects.
    
    # Note:
    #   This is synonome for the function window() which should 
    #   be preferred.
    
    # FUNCTION:
    
    # Extract Subset:
    X = timeDate(x, zone = x@FinCenter, FinCenter = "GMT")
    FROM = timeDate(from, zone = x@FinCenter, FinCenter = "GMT")
    TO = timeDate(to, zone = x@FinCenter, FinCenter = "GMT")
    test = (X >= FROM & X <= TO)
    ans = timeDate(X[test], zone = "GMT", FinCenter = x@FinCenter)
    
    # Return Value:
    ans
}


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