| 1 | = U_init_obsvar_l = |
| 2 | |
| 3 | The page documents the user-supplied call-back routine `U_init_obsvar_l`. |
| 4 | |
| 5 | The routine `U_init_obsvar_l` is a call-back routine that has to be provided by the user. In the simplified interface the predefined name of the routine is `init_obsvar_l_pdaf`, but in the full interface, the user can choose the name of the routine. |
| 6 | The routine is called in the local filters during the loop over all local analysis domains by the routine that computes a local adaptive forgetting factor (`PDAF_set_forget_l`). The routine has to initialize a local mean observation error variance for all observations used for the analysis in the specified local analysis domain. |
| 7 | The routine is only called if the local adaptive forgetting factor is used (`type_forget=2` in the example implementation). When the routine is called it has to return the mean observation error variance for the local observation domain. |
| 8 | |
| 9 | The interface is the following: |
| 10 | {{{ |
| 11 | SUBROUTINE init_obsvar_l(domain_p, step, dim_obs_l, obs_l, meanvar_l) |
| 12 | }}} |
| 13 | with |
| 14 | * `domain_p` : `integer, intent(in)`[[BR]] Index of current local analysis domain |
| 15 | * `step` : `integer, intent(in)`[[BR]] Current time step |
| 16 | * `dim_obs_l` : `integer, intent(in)`[[BR]] Local dimension of observation vector |
| 17 | * `obs_l` : `real, intent(in), dimension(dim_obs_p)`[[BR]] Local observation vector |
| 18 | * `meanvar_l` : `real, intent(out)`[[BR]] Mean local observation error variance |
| 19 | |
| 20 | Notes: |
| 21 | * If the local adaptive forgetting factor is not used, this routine has only to exist for the compilation, but it does not need functionality. |