alarm_fex.tex

CCSM Research Tools: Community Atmosphere Model (CAM)

% $Id: Alarm_fex.tex,v 1.1.6.1 2002/04/24 03:25:47 erik Exp $

The example below demonstrates basic usage of the {\tt Alarm} class.

We initialize a monthly {\tt Alarm} for use with a {\tt TimeMgr}.  As the {\tt TimeMgr} advances 
the model calendar, the {\tt Alarm} is triggered on monthly boundaries.  It is up to the user to 
reset the {\tt Alarm} to an ``off'' state once it has been triggered.  Advancement
stops when the {\tt TimeMgr} recognizes that it is on the last timestep.  Since no memory is allocated 
from the heap when an {\tt Alarm} is initialized, there is no need to deallocate an {\tt Alarm} object.

\begin{verbatim}

  use ESMF_TimeMgmtMod

  type(ESMF_Time) :: stepSize
  type(ESMF_Date) :: startDate, endDate
  type(ESMF_TimeMgr) :: timeMgr
  type(ESMF_Alarm) :: alarm

!-------------------------------------------------------------------------------    
! Initialize the model timestep to 1 day, 1800 seconds; the start date to 
! December 1, 2001 and 0 seconds and the end date to March 14, 2003 and 
! 0 seconds.  Dates are represented in a YYYYMMDD format.  A Gregorian 
! calendar is used.
!-------------------------------------------------------------------------------

  stepSize = ESMF_TimeInit(1, 1800)
  startDate = ESMF_DateInit(ESMF_GREGORIAN, 20011201, 0)
  endDate = ESMF_DateInit(ESMF_GREGORIAN, 20030314, 0)
      
!-------------------------------------------------------------------------------    
! Initialize the time manager and alarm.
!-------------------------------------------------------------------------------

  alarm = ESMF_AlarmInitMonthly();
  timeMgr = ESMF_TimeMgrInit(stepSize, startDate, stopDate)

!-------------------------------------------------------------------------------    
! Advance the model until the end date, triggering the alarm at monthly bounds.
! The alarm is reset at each iteration.
!-------------------------------------------------------------------------------

  do while (.NOT. ESMF_TimeMgrLastStep(timeMgr))
    call ESMF_TimeMgrAdvance(timeMgr)
    if(ESMF_AlarmIsOn(alarm, timeMgr)) then
      ! Perform triggered activity
    end if
    call ESMF_AlarmSet(alarm, .FALSE.)
  end do

\end{verbatim}