SUBROUTINE timestep_scheme_steering

!--------------------------------------------------------------------------------!
! This file is part of PALM.
!
! PALM 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 3 of the License, or (at your option) any later version.
!
! PALM 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.
!
! You should have received a copy of the GNU General Public License along with
! PALM. If not, see <http://www.gnu.org/licenses/>.
!
! Copyright 1997-2014 Leibniz Universitaet Hannover
!--------------------------------------------------------------------------------!
!
! Current revisions:
! ------------------
!
!
! Former revisions:
! -----------------
! $Id: timestep_scheme_steering.f90 1310 2014-03-14 08:01:56Z fricke $
!
! 1036 2012-10-22 13:43:42Z raasch
! code put under GPL (PALM 3.9)
!
! 1001 2012-09-13 14:08:46Z raasch
! all actions concerning leapfrog scheme removed
!
! 673 2011-01-18 16:19:48Z suehring
! No pressure term during time integration (tsc(4)=0.0).
!
! RCS Log replace by Id keyword, revision history cleaned up
!
! Revision 1.2  2005/03/26 21:17:06  raasch
! No pressure term for Runge-Kutta-schemes (tsc(4)=0.0)
!
! Revision 1.1  2004/01/28 15:34:47  raasch
! Initial revision
!
!
! Description:
! ------------
! Depending on the timestep scheme set the steering factors for the prognostic
! equations.
!------------------------------------------------------------------------------!

    USE control_parameters

    IMPLICIT NONE


    IF ( timestep_scheme(1:5) == 'runge' )  THEN
!
!--    Runge-Kutta schemes (here the factors depend on the respective
!--    intermediate step)
       IF ( timestep_scheme == 'runge-kutta-2' )  THEN
          IF ( intermediate_timestep_count == 1 )  THEN
             tsc(1:5) = (/ 1.0, 1.0,  0.0, 0.0, 0.0 /)
          ELSE
             tsc(1:5) = (/ 1.0, 0.5, -0.5, 0.0, 1.0 /)
          ENDIF
       ELSE
          IF ( intermediate_timestep_count == 1 )  THEN
             tsc(1:5) = (/ 1.0,   1.0/3.0,        0.0, 0.0, 0.0 /)
          ELSEIF ( intermediate_timestep_count == 2 )  THEN
             tsc(1:5) = (/ 1.0, 15.0/16.0, -25.0/48.0, 0.0, 0.0 /)
          ELSE
             tsc(1:5) = (/ 1.0,  8.0/15.0,   1.0/15.0, 0.0, 1.0 /)
          ENDIF          
       ENDIF

    ELSEIF ( timestep_scheme == 'euler' )  THEN
!
!--    Euler scheme
       tsc(1:5) = (/ 1.0, 1.0, 0.0, 0.0, 1.0 /)

    ENDIF


 END SUBROUTINE timestep_scheme_steering