Changes between Initial Version and Version 1 of PDAF_diag_stddev_nompi

Timestamp:

Mar 21, 2025, 2:47:12 PM (12 days ago)

Author:

lnerger

Comment:

--

PDAF_diag_stddev_nompi

@@ +1 @@
+= PDAF_diag_stddev_nompi = 
+
+This page documents the routine `PDAF_diag_stddev_nompi` of PDAF, which was introduced with PDAF V3.0.
+
+This routine computes mean ensemble standard deviation.
+
+The routine can be called in the pre/poststep routine of PDAF both before and after the analysis step to compute the ensemble statistics. This variant only compute the standard deviation for the provided ensemble array `ens`. Thus, with a domain-decomposed parallel model, the value of of the standard deviation doe snot consider the full domain. The variant taking into account parallelization is [wiki:PDAF_diag_stddev].
+
+The interface is the following: 
+{{{
+SUBROUTINE PDAF_diag_stddev_nompi(dim, dim_ens, &
+     state, ens, stddev, do_mean, status)
+}}}
+with the following arguments:
+{{{
+  INTEGER, INTENT(in) :: dim               !< state dimension
+  INTEGER, INTENT(in) :: dim_ens           !< Ensemble size
+  REAL, INTENT(inout) :: state(dim)        !< State vector
+  REAL, INTENT(in)    :: ens(dim, dim_ens) !< State ensemble
+  REAL, INTENT(out)   :: stddev            !< Standard deviation of ensemble
+  INTEGER, INTENT(in) :: do_mean           !< Whether to compute ensemble mean
+  INTEGER, INTENT(out) :: status           !< Status flag (0=success)
+}}}
+
+**Note:**
+ * The ensemble standard deviation is a common measure of the estimate model root mean square error. It is typically computed in `prepoststep_pdaf` to monitor the assimilation process.