Changes between Version 2 and Version 3 of OfflineInitPdaf
- Timestamp:
- Apr 12, 2012, 11:44:02 AM (13 years ago)
Legend:
- Unmodified
- Added
- Removed
- Modified
-
OfflineInitPdaf
v2 v3 18 18 == Overview == 19 19 20 After the initialization of the parallelization for the assimilation program, the initialization of PDAF has to be implemented. Internally to PDAF, the initialization is performed by the routine `PDAF_init`. Typically, the initialization s of all variables required for the call to `PDAF_init` can be collected into a single subroutine. This implementation strategy is useful, as only a single additionsubroutine call has to be added to the model source code. In the example in `testsuite/src/offline_1D` the routine in the file `init_pdaf_offline_D.F90` shows this strategy. The file `init_pdaf.F90` in `templates/` provides a commented template for this routine, which can be used as the basis of the implementation.20 After the initialization of the parallelization for the assimilation program, the initialization of PDAF has to be implemented. Internally to PDAF, the initialization is performed by the routine `PDAF_init`. Typically, the initialization of all variables required for the call to `PDAF_init` can be collected into a single subroutine. This implementation strategy is useful, as only a single additional subroutine call has to be added to the model source code. In the example in `testsuite/src/offline_1D` the routine in the file `init_pdaf_offline_D.F90` shows this strategy. The file `init_pdaf.F90` in `templates/` provides a commented template for this routine, which can be used as the basis of the implementation. 21 21 22 `PDAF_init` itself calls a user-supplied routine to initialize the ensemble of model states through its interface. In the example there are separate routines for the different filters. They are in the files `init_seik_offline_D.F90` (for SEIK, LSEIK, ETKF, LETKF ), `init_enkf_offline_D.F90` (for EnKF), and `init_seek_offline_D.F90` (for SEEK).22 `PDAF_init` itself calls a user-supplied routine to initialize the ensemble of model states through its interface. In the example there are separate routines for the different filters. They are in the files `init_seik_offline_D.F90` (for SEIK, LSEIK, ETKF, LETKF, ESTKF, LESTKF), `init_enkf_offline_D.F90` (for EnKF), and `init_seek_offline_D.F90` (for SEEK). 23 23 24 24 == Using `init_pdaf` == … … 26 26 In the offline mode, the routine `init_pdaf` is executed after the initialization of the parallelization. (Note: In the main program of example implementation (`main/main_offine.F90`) we added a call to a routine `initialize` in between for clarity of the implementation. As no real model initialization is conducted, this routine simply initializes the size of the model state. This initialization could also be performed in `init_pdaf`.) 27 27 28 In the routine `init_pdaf` a number of variables are defined that are used in the call to `PDAF_init` as described in '[#RequiredargumentsforPDAF_init Required arguments for `PDAF_init`]'. (Please note: All names of subroutines that start with `PDAF_` are core routines of PDAF, while subroutines whose name end with `_pdaf` are generally user-supplied interface routines) There are also a few variables that are initialized in `init_pdaf` but not used in the call to `PDAF_init`. These are variables that are specific for the data assimilation system, but only shared in between the user-supplied routines. For the example case, these variables are described in '[#Othervariablesfortheassimilation Other variables for the assimilation]'28 In the routine `init_pdaf` a number of variables are defined that are used in the call to `PDAF_init` as described below in '[#RequiredargumentsforPDAF_init Required arguments for `PDAF_init`]'. (Please note: All names of subroutines that start with `PDAF_` are core routines of PDAF, while subroutines whose name end with `_pdaf` are generally user-supplied call-back routines) There are also a few variables that are initialized in `init_pdaf` but not used in the call to `PDAF_init`. These are variables that are specific for the data assimilation system, but only shared in between the user-supplied routines. For the example case, these variables are described below in the section '[#Othervariablesfortheassimilation Other variables for the assimilation]' 29 29 30 The example implementation and the template version allow to parse all variables through a command line parser. This method provides a convenient way to define an experiment and could also be used for other models. The parser module is provided as `te mplates/parser_mpi.F90`30 The example implementation and the template version allow to parse all variables through a command line parser. This method provides a convenient way to define an experiment and could also be used for other models. The parser module is provided as `testsuite/src/main/parser_mpi.F90` 31 31 32 32 == Required arguments for `PDAF_init` == … … 39 39 COMM_model, COMM_filter, COMM_couple, & 40 40 task_id, n_modeltasks, filterpe, & 41 U_ ensemble_init, screen, status_pdaf)41 U_init_ens, screen, status_pdaf) 42 42 }}} 43 43 … … 51 51 * 4: ETKF 52 52 * 5: LETKF 53 * 6: ESTKF 54 * 7: LESTKF 53 55 * `subtype`: An integer defining the sub-type of the filter algorithm (always 5 for the offline mode) 54 56 * `step_null`: Always 0 for the offline mode. … … 66 68 * `n_modeltasks`: The number of model tasks as defined before the call to `init_parallel_pdaf`. 67 69 * `filterpe`: The flag showing if a process belongs to `COMM_filter` as initialized by `init_parallel_pdaf`. 68 * `U_ ensemble_init`: The name of the user-supplied routine that is called by `PDAF_init` to initialize the ensemble of model states. (See '[#User-suppliedroutineU_ensemble_init User-supplied routine U_ensemble_init]'70 * `U_init_ens`: The name of the user-supplied routine that is called by `PDAF_init` to initialize the ensemble of model states. (See '[#User-suppliedroutineU_init_ens User-supplied routine U_init_ens]' 69 71 * `screen`: An integer defining whether information output is written to the screen (i.e. standard output). The following choices are available: 70 72 * 0: quite mode - no information is displayed. … … 87 89 It is useful to define variables lke these at this central position. Of course, this definition has to be adapted to the particular model used. 88 90 89 == User-supplied routine `U_ ensemble_init` ==91 == User-supplied routine `U_init_ens` == 90 92 91 The user-supplied routine the we named `U_ ensemble_init` here, is called by PDAF through the defined interface described below. The routine is called by all MPI processes that compute the filter analysis step (i.e. those for which 'filterpe' is set to true. In the standard configuration of init_parallel_pdaf these are all processes of the first model task, i.e. task_id=1.) `U_ensemble_init` is only called by `PDAF_init` if no error occurred before; thus the status flag is zero.93 The user-supplied routine the we named `U_init_ens` here, is called by PDAF through the defined interface described below. The routine is called by all MPI processes that compute the filter analysis step (i.e. those for which 'filterpe' is set to true. In the standard configuration of `init_parallel_pdaf` these are all processes of the first model task, i.e. task_id=1.) `U_init_ens_pdaf` is only called by `PDAF_init` if no error occurred before; thus the status flag is zero. 92 94 93 95 The interface is the following: 94 96 {{{ 95 SUBROUTINE U_ ensemble_init(filtertype, dim_p, dim_ens, &97 SUBROUTINE U_init_ens(filtertype, dim_p, dim_ens, & 96 98 state_p, Uinv, ens_p, flag) 97 99 }}} … … 105 107 * `flag`: Status flag for PDAF. It is 0 upon entry and can be set by in the user-supplied routine, depending on the success of the ensemble initialization. Preferably, values above 102 should be used for failures to avoid conflicts with the error codes defined within PDAF_init. 106 108 107 In the initialization routine `U_ ensemble_init` one has to distinguish between ensemble-based and mode-based filters. The only mode based filter supplied with PDAF is SEEK, while all other methods are ensemble-based.109 In the initialization routine `U_init_ens_pdaf` one has to distinguish between ensemble-based and mode-based filters. The only mode based filter supplied with PDAF is SEEK, while all other methods are ensemble-based. 108 110 109 111 === Initialization for ensemble-based filters === 110 112 111 Generally, the filters SEIK, LSEIK, EnKF, ETKF, and LETKF are ensemble-based filters. For these filters only the array `ens_p` needs to be initialized by the ensemble of model states. If a model with domain decomposition is used, the full ensemble for the local sub-domain of the MPI process has to be initialized.113 Generally, the filters SEIK, LSEIK, EnKF, ETKF, LETKF, ESTKF, and LESTKF are ensemble-based filters. For these filters only the array `ens_p` needs to be initialized by the ensemble of model states. If a model with domain decomposition is used, the full ensemble for the local sub-domain of the MPI process has to be initialized. 112 114 113 115 The arrays `state_p` and `Uinv` are allocated to their correct sizes because they are used during the assimilation cycles. They are not yet initialized and it is allowed to use these arrays in the initialization. An exception from this is EnKF for which `Uinv` is allocated only with size (`1`,`1`), because `Uinv` is not using for EnKF. … … 127 129 Standard output from PDAF_init should look like the following: 128 130 {{{ 129 PDAF: Initialize SEIK Filter 131 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 132 +++ PDAF +++ 133 +++ Parallel Data Assimilation Framework +++ 134 +++ +++ 135 +++ Version 1.8 +++ 136 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 130 137 131 SEIK configuration 132 filter sub-type = 0 133 --> Standard SEIK 134 --> Transform ensemble with deterministic Omega 138 139 PDAF: Initialize filter 140 141 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 142 +++ SEEK Filter +++ 143 +++ +++ 144 +++ Pham et al., J. Mar. Syst. 16 (1998) 323 +++ 145 +++ This implementation follows +++ 146 +++ Nerger et al., Tellus 57A (2005) 715 +++ 147 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 148 149 SEEK configuration 150 filter sub-type = 5 151 --> offline mode 135 152 --> Use fixed forgetting factor: 1.00 153 --> number of EOFs: 49 154 Perform re-diagonalization 155 156 PDAF: Initialize Parallelization 136 157 137 158 Parallelization - Filter on model PEs: 138 Total number of PEs: 4139 Number of parallel model tasks:1140 PEs for Filter: 4159 Total number of PEs: 1 160 Number of parallel model tasks: 1 161 PEs for Filter: 1 141 162 # PEs per ensemble task and local ensemble sizes: 142 163 Task 1 143 #PEs 4 144 N 300 164 #PEs 1 165 N 49 166 Evolve central state on task: 1 145 167 }}} 146 168 147 The correctness of the ensemble initialization in `U_ ensemble_init` should be checked by the user.169 The correctness of the ensemble initialization in `U_init_ens` should be checked by the user.
