source: XIOS/trunk/src/date/gregorian.cpp @ 550

Last change on this file since 550 was 550, checked in by rlacroix, 6 years ago

Add a new user defined calendar type.

A new calendar type "user_defined" is now available. This allows the users to create a custom calendar that we can configured to be suitable for planets other than the Earth.

An user defined calendar is always defined by two mandatory attributes:

  • day_length: the duration of a day, in seconds
  • and either:
    • month_length: an array containing the duration of each month, in days (the number of elements in the array is the number of months in a year)
    • or year_length: the duration of a year, in seconds (in that case, the calendar does not have months).

If the calendar has months (i.e. month_length attribute is set) and only in that case, it is possible to define leap years in order to compensate for the duration of an astronomical year not being a multiple of the day length. The leap years are defined by two mandatory attributes:

  • leap_year_month: the month to which the extra day will be added in case of leap year, expressed as an integer number in the range [1, numberOfMonths]
  • and leap_year_drift: the fraction of a day representing the yearly drift between the calendar year and the astronomical year, expressed as a real number in the range [0, 1).

Optionally, one can define the leap_year_drift_offset attribute to set the original drift at the beginning of the time origin's year, again expressed as a real number in the range [0, 1). If leap_year_drift_offset + leap_year_drift is greater or equal to 1, then the first year will be a leap year.

For example, the following configuration creates a Gregorian-like calendar:

<calendar type="user_defined" start_date="2012-03-01 15:00:00" time_origin="2012-02-28 15:00:00 + 1d" day_length="86400" month_lengths="(1, 12) [31 28 31 30 31 30 31 31 30 31 30 31]" leap_year_month="2" leap_year_drift="0.25" leap_year_drift_offset="0.75" />

Note that dates attributes must be written differently in the configuration file when using an user defined calendar without months:

  • if the year length is greater than the day length, the input format is year-day hh:min:sec instead of year-month-day hh:min:sec
  • if the day length is greater or equal to the year length, the input format is year hh:min:sec.

In all cases, it is still possible to use the date + duration notation to build a date (with both the date and duration parts being optional).

The Fortran interface has been updated accordingly so that xios_define_calendar can accept the new attributes necessary to define custom calendars.

  • Property copyright set to
    Software name : XIOS (Xml I/O Server)
    http://forge.ipsl.jussieu.fr/ioserver
    Creation date : January 2009
    Licence : CeCCIL version2
    see license file in root directory : Licence_CeCILL_V2-en.txt
    or http://www.cecill.info/licences/Licence_CeCILL_V2-en.html
    Holder : CEA/LSCE (Laboratoire des Sciences du CLimat et de l'Environnement)
    CNRS/IPSL (Institut Pierre Simon Laplace)
    Project Manager : Yann Meurdesoif
    yann.meurdesoif@cea.fr
File size: 2.3 KB
Line 
1#include "gregorian.hpp"
2
3namespace xios
4{
5      /// ////////////////////// Définitions ////////////////////// ///
6
7      CGregorianCalendar::CGregorianCalendar(const CDate& startDate)
8         : CCalendar("Gregorian", startDate)
9      {
10         // This will check that the dates are conform with the calendar.
11         // We cannot call this from the parent constructor because we
12         // want the methods of this class to be used
13         initializeDate();
14      }
15
16      CGregorianCalendar::CGregorianCalendar(const CDate& startDate, const CDate& timeOrigin)
17         : CCalendar("Gregorian", startDate, timeOrigin)
18      {
19         // This will check that the dates are conform with the calendar.
20         // We cannot call this from the parent constructor because we
21         // want the methods of this class to be used
22         initializeDate();
23      }
24
25      CGregorianCalendar::CGregorianCalendar(int yr, int mth, int d,
26                                             int hr, int min, int sec)
27         : CCalendar("Gregorian")
28      { initializeDate(yr, mth, d, hr, min, sec) ; }
29
30      CGregorianCalendar::~CGregorianCalendar(void)
31      { /* Ne rien faire de plus */ }
32
33      ///--------------------------------------------------------------
34
35      int CGregorianCalendar::getYearTotalLength(const CDate& date) const
36      { // Retourne la durée d'une année en seconde.
37         if ((date.getYear() % 4   == 0) &&
38            ((date.getYear() % 100 != 0)  ||
39             (date.getYear() % 400 == 0)  ))
40            return (366 * 86400);
41         return (365 * 86400);
42      }
43
44      int CGregorianCalendar::getMonthLength(const CDate& date) const
45      { // Retourne la durée du mois en jour.
46         if (date.getMonth() == 2)
47         { // Traitement du cas particulier en Février.
48            if ((date.getYear() % 4   == 0) &&
49               ((date.getYear() % 100 != 0) ||
50                (date.getYear() % 400 == 0) ))
51               return (29);
52            return (28);
53         }
54         return (CCalendar::getMonthLength(date));
55      }
56
57      StdString CGregorianCalendar::getType(void) const
58      { return (StdString("gregorian")); }
59
60      bool CGregorianCalendar::hasLeapYear() const { return true; }
61
62      ///--------------------------------------------------------------
63} // namespace xmlioserver
64
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