MODULE reg_factor¶

Overview¶

Computes a weighting factor to reduce the impact of observations on state variables using information from groups of ensembles. Can be run using groups or using archived summary information available from previous group filter experiments.

Other modules used¶

types_mod
utilities_mod
time_manager_mod

Public interfaces¶

use reg_factor_mod, only :

comp_reg_factor

A note about documentation style. Optional arguments are enclosed in brackets [like this].

var = comp_reg_factor(num_groups, regress, obs_index, state_index [, obs_state_ind] [, obs_state_max])

real(r8)                                    ::  comp_reg_factor
integer,                         intent(in) ::  num_groups
real(r8), dimension(num_groups), intent(in) ::  regress
integer,                         intent(in) ::  obs_index
integer,                         intent(in) ::  state_index
integer, optional,               intent(in) ::  obs_state_ind
integer, optional,               intent(in) ::  obs_state_max

Returns a weighting factor given regression factors from each group of a group filter or retrieves a factor generated by previous group filter runs from a file.

`num_groups`	Number of groups. Set to 1 when using information from previously run group filter from file.
`regress`	Regression factor from each group for a given state variable and observation variable pair.
`obs_index`	Integer index of the observation being processed. Not used in current implementation .
`state_index`	Integer index of state variable being processed. Not used in current implementation.
obs_state_ind	Index into file generated for Bgrid model which could be duplicated in other large models.
obs_state_max	Maximum number of observation state variable pairs with non-zero impacts for a given model and observation sequence. Used for generating Bgrid statistic files.

Namelist¶

This namelist is read from the file input.nml. Namelists start with an ampersand ‘&’ and terminate with a slash ‘/’. Character strings that contain a ‘/’ must be enclosed in quotes to prevent them from prematurely terminating the namelist.

&reg_factor_nml
   select_regression    = 1,
   input_reg_file       = "time_mean_reg",
   save_reg_diagnostics = .false.,
   reg_diagnostics_file = "reg_diagnostics"
/

Item	Type	Description
select_regression	integer	Selects the method for computing regression factor. 1 = compute using sampling theory for any ensemble size. 2 = low order model format. Works from archived time mean or time median regression files generated by low-order models like Lorenz-96. 3 = selects bgrid archived file. This is not currently supported in released versions.
input_reg_file	character(len=129)	File name from which statistics are to be read for select_regression = 3.
save_reg_diagnostics	logical	True if regression diagnostics should be computed.
reg_diagnostics_file	character(len=129)	File name to which to write diagnostics.

Files¶

(optional) input regression file from namelist variable input_reg_file.
reg_factor_mod.nml in input.nml

filename	purpose
from `input.nml`&reg_factor_mod:input_reg_file	file of regression coefficients

References¶

none

Private components¶

N/A