Changes between Version 12 and Version 13 of AddFilterAlgorithm


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Timestamp:
Nov 16, 2011, 10:21:18 AM (13 years ago)
Author:
lnerger
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  • AddFilterAlgorithm

    v12 v13  
    55This text describes the implementation strategy and internal structure of PDAF valid for version 1.7.0 and later. If you use an earlier version of PDAF, we recommend to update to the most recent version. In this text, we assume that the reader is already familiar with PDAF to the extend of experience with the implementation of a model with PDAF that is described in the [ImplementationGuide implementation guide].
    66
    7 The internal structure of PDAF is organized into a generic part providing the infrastructure to perform ensemble forecasts and filter analysis steps. The generic part is independent of the particular filter algorithm and only distinguishes between ensemble based filters (all filters except SEEK) and mode based filters (currently only SEEK). The filter-specific routines are called through an internal interface.
     7The internal structure of PDAF is organized into a generic part providing the infrastructure to perform ensemble forecasts and filter analysis steps. This generic part is independent of the particular filter algorithm and only distinguishes between ensemble based filters (all filters except SEEK) and mode based filters (currently only SEEK). The filter-specific routines are called through an internal interface.
    88
    99Each filter algorithm consists of 6 routines that are described below. All routines are called trough the internal interface of PDAF, except for the "put state" routine (`PDAF_put_state_X` where X is the name of the selected filter).
     
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    33 The routine `PDAF_put_state_X` is called directly from the model code. There is a separate routine for each filter. The standard implementation  calls
     33The routine `PDAF_put_state_X` is called directly from the model code. There is a separate routine for each filter, mainly because of the fact that different user-supplied routines may be needed for the analysis step of the filter. However, the operations performed directly in `PDAF_put_state_X` are widely generic and the filter-specific analysis step is typically implemented as another subroutine.
     34The standard implementation calls
    3435 * `PDAF_X_initinfo`
    3536   * This is the same routine that is called by `PDAF_get_state`. Here, it is only called, if the offline mode of PDAF is used.
    3637 * `PDAF_X_update`
    37    * This routine contains the actual assimilation or analysis step of the filter algorithm.
     38   * This routine contains the actual assimilation or analysis step of the filter algorithm. 
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    5253In addition, the routine
    5354 * `PDAF_put_state_X`
    54 has to be implemented.
     55has to be implemented that is called directly in the model code.
    5556
    5657We recommend to base on the routines of an existing filter, as most of the routines can be easily adapted to a new filter method.