= PDAF_diag_compute_moments = 

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

This routine computes the mean, the unbiased variance, the unbiased skewness, and the unbiased excess kurtosis from an ensemble. All moments are stored in a single array. `kmax` controls the highest order that should be computed.

The routine can be called in the pre/poststep routine of PDAF both before and after the analysis step to compute the ensemble statistics.

The interface is the following: 
{{{
SUBROUTINE PDAF_diag_compute_moments(dim_p, dim_ens, ens, kmax, moments) 
}}}

with the following arguments: 

-  `dim_p` : INTEGER, INTENT(IN) [[BR]] Size of the state vector 

-  `dim_ens` : INTEGER, INTENT(IN) [[BR]] Ensemble size

-  `ens` : REAL, DIMENSION(dim_p,dim_ens), INTENT(IN)[[BR]] Ensemble matrix

-  `kmax` : INTEGER, INTENT(IN) [[BR]] Highest order of statistical moment (1-4)

-  `moments` : REAL, DIMENSION(dim_p,kmax), INTENT(OUT) [[BR]] The statistical moments up to order `kmax` with
  - column 1: mean
  - column 2: variance
  - column 3: skewness
  - colmnu 4: excess kurtosis