PDAF_gather_obs_f

This page documents the routine PDAF_gather_obs_f of PDAF, which was introduced with PDAF V1.13.

In the local filters (LESKTF, LETKF, LSEIK, LNETF) this routine gathers the full observation vector dimension from process-local observation vectors of size dim_obs_p and returns the full vector.

The routine depends on PDAF_gather_dim_obs_f, which defines the process-local observation dimensions. Further, the related routine PDAF_gather_obs_f2 is used to gather the associated rank-2 array of observation coordinates.

The routine is typically used in the routines init_dim_obs_f_pdaf and obs_op_f_pdaf if the analysis step of the local filters is parallelized.

The interface is the following:

  SUBROUTINE PDAF_gather__obs_f(obs_p, obs_f, status)

with the following arguments:

• obs_p : real, intent(in), dimension(dim_obs_p)
  Process-local observation vector
• obs_f : real, intent(out), dimension(dim_obs_f)
  Full observation vector
• status : integer, intent(out)
  Status flag (0 for no error)

Notes:

• The routine PDAF_gather_dim_obs_f has to be called once before using PDAF_gather_obs_f because it internally initializes the local observation dimensions for gathering. The most recent call to PDAF_gather_dim_obs_f defines the dimensions dim_obs_p and dim_obs_f used here.
• For cases with different observation types, the routine PDAF_gather_obs_f_flex can be used. It does not rely on PDAF_gather_dim_obs_f and is hence easier to use. It was introduced in PDAF 1.14.