PDAF_set_rparam

This page documents the routine PDAF_set_rparam of PDAF, which was introduced with PDAF V3.0.

This routine is used to set real-valued (floating-point) parameters for PDAF.

The real-value parameters specific to a DA method can be set in the array filter_param_r that is an argument of PDAF_init (see the page on initializing PDAF). PDAF_set_rparam provides an alternative way. Instead of providing all parameters in the call to PDAF_init, one can provide only the required minimum for this call. Afterwards, one can then call PDAF_set_rparam for each integer parameter that one intends to specify differently from the default value. An advantage of using PDAF_set_rparam is that one only needs to call it for parameters that one intends to change, while in the call to PDAF_init, all parameters up to the index one intends to change have to be specified, even if one does not want to change a parameter value. The tutorials and templates show the use of PDAF_set_rparam.

The routine is usually called by all processes after the call to PDAF_init in init_pdaf. One can also call the routine at a later time during an assimilation process to change parameters. The parameter will be set for the DA method that was specified in the call to PDAF_init.

The interface is the following:

  SUBROUTINE PDAF_set_rparam(id, value, flag)

    INTEGER, INTENT(in) :: id       ! Index of the parameter that is set
    REAL, INTENT(in)    :: value    ! Value of the parameter
    INTEGER, INTENT(inout) :: flag  ! Status flag: 0 for no error

Hints:

• The available parameter options are listed in the Overview of available DA method-specific options.
• The status variable flag is incremented by the routine. Thus, PDAF_set_rparam can be called directly after calling PDAF_init, and several calls to PDAF_set_rparam or PDAF_set_iparam can be done one after the other. It is sufficient to check the values of flag after this series of calls.