= Module `PDAF` =

The module `PDAF` was introduced with PDAF V3.0 and replaces the previous module `PDAF_interfaces_module`.

The module `PDAF` has to be include with `use` in all routines that that call PDAF routines or functions:
{{{
  use PDAF
}}}

The module provides interface definitions for the routines of PDAF. With this one gets an explicit Fortran interface so that the compiler can check the consistency of arguments.

The module also provides the definition of types of DA methods as named parameters of the form `PDAF_DA_X`, e.g. the LESTKF with PDAF_DA_LESTKF, and their related DA-method value which is specified in the call to `PDAF_init`. One can print a list of the DA-method types using [wiki:PDAF_print_DA_types].