wiki:PDAF_put_state_seek

Version 3 (modified by lnerger, 6 years ago) (diff)

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PDAF_put_state_seek

This page documents the routine PDAF_put_state_seek of PDAF.

The routine is typically called in assimilate_pdaf or directly in the model code.

The routines PDAF_put_state_* are used with the 'flexible' implementation variant of PDAF. The general aspects of the filter specific routines PDAF_put_state_* are described on the page Modification of the model code for the ensemble integration and its sub-page on inserting the analysis step. For the 'fully parallel' implementation variant the alternative routines PDAF_assimilate_* are used.

The interface when using the SEEK filter is the following:

  SUBROUTINE PDAF_put_state_seek(U_collect_state, U_init_dim_obs, U_obs_op, &
                                 U_init_obs, U_prepoststep, U_prodRinvA, status_pdaf)

with the following arguments:

  • U_collect_state: The name of the user-supplied routine that initializes a state vector from the array holding the ensemble of model states from the model fields. This is basically the inverse operation to U_distribute_state used in PDAF_get_state.
  • U_init_dim_obs: The name of the user-supplied routine that provides the size of observation vector
  • U_obs_op: The name of the user-supplied routine that acts as the observation operator on some state vector
  • U_init_obs: The name of the user-supplied routine that initializes the vector of observations
  • U_prepoststep: The name of the pre/poststep routine as in PDAF_get_state
  • U_prodRinvA: The name of the user-supplied routine that computes the product of the inverse of the observation error covariance matrix with some matrix provided to the routine by PDAF. This operation occurs during the analysis step of the SEEK filter.
  • status_pdaf: The integer status flag. It is zero, if PDAF_assimilate_seek is exited without errors.

The user-supplied call-back routines are described on the page on implementing the analysis step of the SEEK filter.

It is recommended that the value of status_pdaf is checked in the program after PDAF_put_state_seek is executed. Only if its value is 0 the initialization was successful.

PDAF also has a Simplified Interface providing the routine PDAF_put_state_seek. In the simplified interface, the name of the user-supplied routines have predefined names and do not appear in the call to PDAF_put_state_seek. More information on the pre-defined names is provided in the page on implementing the analysis step of the SEEK filter.