Presentation is loading. Please wait.

Presentation is loading. Please wait.

Jörg Uhlenbrock Universität Hannover Institut für Meteorologie und Klimatologie PALM-Seminar 8.-14.7.2003 How to work with the user-interface-routine in.

Similar presentations


Presentation on theme: "Jörg Uhlenbrock Universität Hannover Institut für Meteorologie und Klimatologie PALM-Seminar 8.-14.7.2003 How to work with the user-interface-routine in."— Presentation transcript:

1 Jörg Uhlenbrock Universität Hannover Institut für Meteorologie und Klimatologie PALM-Seminar How to work with the user-interface-routine in PALM Contents: Purpose of the user-interface Embedding in PALM Realisation Hints for new users

2 Jörg Uhlenbrock Universität Hannover Institut für Meteorologie und Klimatologie PALM-Seminar Purpose of the user-interface a standardarized model cannot count for all specific interests of the users, but provides the basic simulation and most common outputs => the user should be able to add special, non-standard features in an interface of the model WITHOUT changing the standard code standard version of PALM allows (excerpts): –forcing through time-invariant homogeneous or randomly distributed surface heat flux or temperature – output of time-series, 2D-slices, 3D binary data (AVS), time-averaged profiles and spectra of several meteorological variables –prescription of time-invariant stratification (θ-profile) –…

3 Jörg Uhlenbrock Universität Hannover Institut für Meteorologie und Klimatologie PALM-Seminar Purpose of the user-interface examples of extended features: –time-averaged 2D- and 3D-data –adaption of experimental approaches (e.g. adaption of coarse tomography-grid, prescription of time-variant θ- and wind-profiles) –inhomogeneous surface forcing –… Inhomogeneous surface forcing

4 Jörg Uhlenbrock Universität Hannover Institut für Meteorologie und Klimatologie PALM-Seminar Embedding in PALM the name of the user-interface is …/SOURCE/user_interface.f90 and provides the framework for the entry of user code My recommendations: 1.create an additional directory, e.g. …/SOURCE/USER_CODE 2.create an additional directory named equal to the new run you want to simulate, eg. …/SOURCE/USER_CODE/example -> in.mrun.config there is a search path integrated, so that the model will find your user-files: %add_source_path $HOME/palm/current_version/SOURCE/USER_CODE/$fname 3.copy the original …/SOURCE/user_interface.f90 into this directory 4. add your own user-code and use mrun with the option -s user_interface.f90 (ensure that this file has write permits!) (hint: mrun –s TEST compiles all.f90-files with write-permits)

5 Jörg Uhlenbrock Universität Hannover Institut für Meteorologie und Klimatologie PALM-Seminar to grant access to important parts of the model, there are several subroutines in the user-interface, which are called by the main program: SUBROUTINE user_last_actions Initialization: Run-time: Finishing: SUBROUTINES user_parin user_header user_init SUBROUTINES user_actions (location) user_statistics SUBROUTINE user_init_particles user_particles_attrib utes user_dvrp_coltab

6 Jörg Uhlenbrock Universität Hannover Institut für Meteorologie und Klimatologie PALM-Seminar Initialization PALM parin read_var_listpackage_parinuser_parin init_pegrid init_grid check_parameters header user_header init_3d_model init_*** user_init_particles user_init leap_frog

7 Jörg Uhlenbrock Universität Hannover Institut für Meteorologie und Klimatologie PALM-Seminar Run-time leap_frog 1D topol. standard advection

8 Jörg Uhlenbrock Universität Hannover Institut für Meteorologie und Klimatologie PALM-Seminar Realisation The framework: source code of user_interface.f90 Notepad

9 Jörg Uhlenbrock Universität Hannover Institut für Meteorologie und Klimatologie PALM-Seminar Realisation: location user_actions Excerpt from leap_frog.f90: ! !-- Start of the time loop DO WHILE ( simulated_time < end_time.AND..NOT. stop_dt.AND. &.NOT. terminate_run ) CALL cpu_log( log_point_s(10), 'timesteps', 'start' ) ! !-- Execute the user-defined actions #if defined( __decalpha ) PRINT*, '+++ WARNING: leap_frog: no call of user_actions due to' PRINT*, ' internal compiler error' #else CALL user_actions( 'before_timestep' ) #endif ! !-- Solve the prognostic equations. A fast cache optimized version with !-- only one single loop is used in case of Piascek-Williams advection !-- scheme. NEC vector machines use a different version, because !-- in the other versions a good vectorization is prohibited due to !-- inlining problems. IF ( host(1:3) == 'nec' ) THEN CALL prognostic_equations_vec ELSE IF ( impulse_advec == 'ups-scheme'.OR. & scalar_advec == 'ups-scheme'.OR. & scalar_advec == 'bc-scheme' ) & THEN CALL prognostic_equations ELSE CALL prognostic_equations_fast ENDIF ….. ! !-- Execute user-defined actions #if defined( __decalpha ) PRINT*, '+++ WARNING: leap_frog: no call of user_actions due to' PRINT*, ' internal compiler error' #else CALL user_actions( 'after_timestep' ) #endif ! !-- Determine size of next time step CALL timestep

10 Jörg Uhlenbrock Universität Hannover Institut für Meteorologie und Klimatologie PALM-Seminar Realisation: location user_actions Excerpts from prognostic_equations.f90 … ! !-- Tendency terms for u-velocity component tend(:,j,i) = 0.0 IF ( bt == 2.0 ) THEN CALL advec_u_pw( i, j ) CALL diffusion_u( i, j, ddzu, ddzw, km_m, tend, u_m, usws_m, v_m, & w_m ) ELSE CALL advec_u_up( i, j ) CALL diffusion_u( i, j, ddzu, ddzw, km, tend, u, usws, v, w ) ENDIF CALL coriolis( i, j, 1 ) IF ( sloping_surface ) CALL buoyancy( i, j, pt, 1, 4 ) CALL user_actions( i, j, 'u-tendency' ) ! !-- Prognostic equation for u-velocity component DO k = nzb+1, nzt u_p(k,j,i) = ( 1-at ) * u_m(k,j,i) + at * u(k,j,i) + & bt * dt_3d * tend(k,j,i) - & dt_3d * ( p(k,j,i) - p(k,j,i-1) ) * ddx - & bt * rdf(k) * ( u(k,j,i) - ug ) ENDDO ! !-- Tendency terms for v-velocity component tend(:,j,i) = 0.0 IF ( bt == 2.0 ) THEN CALL advec_v_pw( i, j ) CALL diffusion_v( i, j, ddzu, ddzw, km_m, tend, u_m, v_m, vsws_m, & w_m ) ELSE CALL advec_v_up( i, j ) CALL diffusion_v( i, j, ddzu, ddzw, km, tend, u, v, vsws, w ) ENDIF CALL coriolis( i, j, 2 ) CALL user_actions( i, j, 'v-tendency' ) …… For the call of tendency-terms on the ibm-regatta, a FORTRAN95- functionality called function- overloading is used to allow different argument lists for the same SUBROUTINE, e.g.: CALL user_actions( before_timestep ) in leap_frog.f90, but CALL user_actions(i, j, u-tendency) in prognostic_equations.f90

11 Jörg Uhlenbrock Universität Hannover Institut für Meteorologie und Klimatologie PALM-Seminar Realisation: prerequisites for function overloading the subroutines using this technique have to be embedded in a modular programming structure: MODULE user_actions_mod ! ! ! ! Description: ! ! Execution of user-defined actions before or after single timesteps ! ! PRIVATE PUBLIC user_actions INTERFACE user_actions MODULE PROCEDURE user_actions MODULE PROCEDURE user_actions_ij END INTERFACE user_actions CONTAINS …… ! ! ! Call for all grid points ! ! SUBROUTINE user_actions( location ) …. END SUBROUTINE user_actions ! ! ! Call for grid point i,j ! ! SUBROUTINE user_actions_ij( i, j, location ) … END SUBROUTINE user_actions_ij END MODULE user_actions_mod

12 Jörg Uhlenbrock Universität Hannover Institut für Meteorologie und Klimatologie PALM-Seminar Realisation: change of DO-loop A fast method for computing on the IBM is realized through the change of DO-Loop structure. The call of SUBROUTINES is faster than the direct computation of the arrays within a loop. SUBROUTINE user_actions DO k = … DO j = … DO i = … array1(k,j,i) = array2(k,j,i) + SIN(i) ENDDO END SUBROUTINE user_actions is changed to: SUBROUTINE prognostic_equations DO j = … DO i = … CALL SUBROUTINE user_actions(i, j, location) ENDDO END SUBROUTINE prognostic_equations SUBROUTINE user_actions(i, j, location) DO k = … array1(k,j,i) = array2(k,j,i) + SIN(i) ENDDO END SUBROUTINE user_actions

13 Jörg Uhlenbrock Universität Hannover Institut für Meteorologie und Klimatologie PALM-Seminar Final steps PALM leap_frog write_3d_binary write_var_list header user_last_actions cpu_statistics

14 Jörg Uhlenbrock Universität Hannover Institut für Meteorologie und Klimatologie PALM-Seminar Hints for new users Most important: IF NOT SPECIFIED, ALL OF YOUR ADDED COMMANDS ARE EXECTUED BY ALL PEs!!!! Not less important: YOUR ENTRIES IN THE TENDENCY-LOCATIONS OF SUBROUTINE USER_ACTIONS ACTUALLY ARE IN A TWOFOLD LOOP OF INDICES i and j AND THEREFORE WILL BE COMPUTED i*j TIMES BY EACH PE!!!! In most cases, this is only intended in a computation with at least 2D-arrays in order to compute each element of the array. Use the MODULE user for the declaration of variables and arrays, etc. This leads to a more transparent code. Use SUBROUTINES user_init and user_last_actions to restore and save your data for restart_runs.

15 Jörg Uhlenbrock Universität Hannover Institut für Meteorologie und Klimatologie PALM-Seminar Hints in user_last_actions: !– write fields for restart run IF ( write_binary(1:4) == 'true' ) THEN WRITE (14) 'example _ array '; WRITE (14) example_array WRITE (14) 'example_integer '; WRITE (14) example_integer !-- Set an end mark WRITE ( 14 ) '** end_user_entry ** ' ENDIF <= UNIT (14): BINOUT, all necessary model parameters are stored in here

16 Jörg Uhlenbrock Universität Hannover Institut für Meteorologie und Klimatologie PALM-Seminar Hints Example: in user_init: IF … ELSEIF ( TRIM( initializing_actions ) == 'read_fields_from_prior_run' ) THEN ! !-- Read data frtom prior run. READ ( 13 ) field_chr DO WHILE ( TRIM( field_chr ) /= '** end_user_entry **' ) SELECT CASE ( TRIM( field_chr ) ) CASE ( ' example_array') READ (13) example_array CASE ( ' example_integer') READ (13) example_integer CASE DEFAULT PRINT*, '+++ user_init: unkown field "', & TRIM( field_chr ), '" find in' PRINT*, ' the data of prior run on PE ', myid STOP END SELECT ! !-- Read next character line READ ( 13 ) field_chr ENDDO ENDIF !initializing_actions <= UNIT (13): BININ, all necessary model parameters are returned from here

17 Jörg Uhlenbrock Universität Hannover Institut für Meteorologie und Klimatologie PALM-Seminar The End Any questions?

18 Jörg Uhlenbrock Universität Hannover Institut für Meteorologie und Klimatologie PALM-Seminar Embedding in PALM: subroutine calls in the main program SUBROUTINE user_last_actions SUBROUTINES user_parin user_header user_init SUBROUTINES user_init_particles user_particles_attribute user_dvrp_coltab SUBROUTINESuser_actions user_statistics call in main program: parin.f90 header.f90 init_3d_model.f90 call in main program: init_particles.f90 advec_particles.f90 plot_dvrp.f90 call in main program: leap_frog.f90 leap_frog.f90 (for locations before/after timestep)prognostic_equations.f90 (for locations u,v,w,pt,e,q-tendency) flow_statistics.f90 call in main program: palm.f90


Download ppt "Jörg Uhlenbrock Universität Hannover Institut für Meteorologie und Klimatologie PALM-Seminar 8.-14.7.2003 How to work with the user-interface-routine in."

Similar presentations


Ads by Google