SUBROUTINE user_statistics( mode, sr, tn )

!------------------------------------------------------------------------------!
! Actual revisions:
! -----------------
! 
!
! Former revisions:
! -----------------
! $Id: user_statistics.f90 226 2009-02-02 07:39:34Z franke $
!
! 211 2008-11-11 04:46:24Z raasch
! Former file user_interface.f90 split into one file per subroutine
!
! Description:
! ------------
! Calculation of user-defined statistics, i.e. horizontally averaged profiles
! and time series.
! This routine is called for every statistic region sr defined by the user,
! but at least for the region "total domain" (sr=0).
! See section 3.5.4 on how to define, calculate, and output user defined
! quantities.
!------------------------------------------------------------------------------!

    USE arrays_3d
    USE indices
    USE statistics
    USE user

    IMPLICIT NONE

    CHARACTER (LEN=*) ::  mode

    INTEGER ::  i, j, k, sr, tn


    IF ( mode == 'profiles' )  THEN

!
!--    Sample on how to calculate horizontally averaged profiles of user-
!--    defined quantities. Each quantity is identified by the index
!--    "pr_palm+#" where "#" is an integer starting from 1. These
!--    user-profile-numbers must also be assigned to the respective strings
!--    given by data_output_pr_user in routine user_check_data_output_pr.
!       !$OMP DO
!       DO  i = nxl, nxr
!          DO  j = nys, nyn
!             DO  k = nzb_s_inner(j,i)+1, nzt
!!
!!--             Sample on how to calculate the profile of the resolved-scale
!!--             horizontal momentum flux u*v*
!                sums_l(k,pr_palm+1,tn) = sums_l(k,pr_palm+1,tn) +           &
!                      ( 0.5 * ( u(k,j,i) + u(k,j,i+1) ) - hom(k,1,1,sr) ) * &
!                      ( 0.5 * ( v(k,j,i) + v(k,j+1,i) ) - hom(k,1,2,sr) )   &
!                                                 * rmask(j,i,sr)
!!
!!--             Further profiles can be defined and calculated by increasing
!!--             the second index of array sums_l (replace ... appropriately)
!                sums_l(k,pr_palm+2,tn) = sums_l(k,pr_palm+2,tn) + ... &
!                                         * rmask(j,i,sr)
!             ENDDO
!          ENDDO
!       ENDDO

    ELSEIF ( mode == 'time_series' )  THEN

!
!--    Sample on how to add values for the user-defined time series quantities.
!--    These have to be defined before in routine user_init. This sample
!--    creates two time series for the absolut values of the horizontal
!--    velocities u and v.
!       ts_value(dots_num_palm+1,sr) = ABS( u_max )
!       ts_value(dots_num_palm+2,sr) = ABS( v_max )

    ENDIF

 END SUBROUTINE user_statistics