SUBROUTINE user_read_restart_data( i, nxlfa, nxl_on_file, nxrfa, nxr_on_file, &
                                    nynfa, nyn_on_file, nysfa, nys_on_file,    &
                                    offset_xa, offset_ya, overlap_count,       &
                                    tmp_2d, tmp_3d )

!------------------------------------------------------------------------------!
! Current revisions:
! -----------------
! Output of messages replaced by message handling routine.
!
!
! Former revisions:
! -----------------
! $Id: user_read_restart_data.f90 274 2009-03-26 15:11:21Z weinreis $
!
! 220 2008-12-18 07:00:36Z raasch
! reading mechanism revised (subdomain/total domain size can vary arbitrarily
! between current and previous run),
! former file user_interface.f90 split into one file per subroutine
!
! Description:
! ------------
! Reading restart data from file(s)
! Subdomain index limits on file are given by nxl_on_file, etc.
! Indices nxlc, etc. indicate the range of gridpoints to be mapped from the
! subdomain on file (f) to the subdomain of the current PE (c). They have been
! calculated in routine read_3d_binary.
!------------------------------------------------------------------------------!

    USE control_parameters
    USE indices
    USE pegrid
    USE user

    IMPLICIT NONE

    CHARACTER (LEN=20) :: field_char

    INTEGER ::  i, k, nxlc, nxlf, nxl_on_file, nxrc, nxrf, nxr_on_file, nync, &
                nynf, nyn_on_file, nysc, nysf, nys_on_file, overlap_count

    INTEGER, DIMENSION(numprocs_previous_run,1000) ::  nxlfa, nxrfa, nynfa, &
                                                       nysfa, offset_xa, &
                                                       offset_ya

    REAL, DIMENSION(nys_on_file-1:nyn_on_file+1,nxl_on_file-1:nxr_on_file+1) ::&
          tmp_2d

    REAL, DIMENSION(nzb:nzt+1,nys_on_file-1:nyn_on_file+1, &
                    nxl_on_file-1:nxr_on_file+1) ::        &
          tmp_3d

!
!-- Here the reading of user-defined restart data follows:
!-- Sample for user-defined output
!
!    IF ( initializing_actions == 'read_restart_data' )  THEN
!       READ ( 13 )  field_char
!       DO  WHILE ( TRIM( field_char ) /= '*** end user ***' )
!
!          DO  k = 1, overlap_count
!
!             nxlf = nxlfa(i,k)
!             nxlc = nxlfa(i,k) + offset_xa(i,k)
!             nxrf = nxrfa(i,k)
!             nxrc = nxrfa(i,k) + offset_xa(i,k)
!             nysf = nysfa(i,k)
!             nysc = nysfa(i,k) + offset_ya(i,k)
!             nynf = nynfa(i,k)
!             nync = nynfa(i,k) + offset_ya(i,k)
!
!
!             SELECT CASE ( TRIM( field_char ) )
!
!                CASE ( 'u2_av' )
!                   IF ( .NOT. ALLOCATED( u2_av ) ) THEN
!                      ALLOCATE( u2_av(nzb:nzt+1,nys-1:nyn+1,nxl-1:nxr+1) )
!                   ENDIF
!                   IF ( k == 1 )  READ ( 13 )  tmp_3d
!                   u2_av(:,nysc-1:nync+1,nxlc-1:nxrc+1) = &
!                                          tmp_3d(:,nysf-1:nynf+1,nxlf-1:nxrf+1)
!
!                CASE DEFAULT
!                   WRITE( message_string, * ) 'unknown variable named "',  &
!                                         TRIM( field_char ), '" found in', &
!                                         '&data from prior run on PE ', myid
!                   CALL message( 'user_spectra', 'UI0012', 1, 2, 0, 6, 0 )
!
!             END SELECT
!
!          ENDDO
!
!          READ ( 13 )  field_char
!
!       ENDDO
!    ENDIF

 END SUBROUTINE user_read_restart_data