You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: spm_dcm_post_hoc.m
    path of file: ./repos/spm12
    
    the code of the file until where you have to start completion: function DCM = spm_dcm_post_hoc(P,fun,field,write_all)
% Post hoc optimisation of DCMs (under the Laplace approximation)
% FORMAT DCM = spm_dcm_post_hoc(P,fun,field,write_all)
%
%  P        - character/cell array of DCM filenames
%           - or cell array of DCM structures; where
%  DCM.M.pE - prior expectation (with parameters in pE.A, pE.B and pE.C)
%  DCM.M.pC - prior covariance
%  DCM.Ep   - posterior expectations
%  D
    
function create_plots(DCM,BPA,Pk,Pf,params,extra_plots)
% Plot results
%--------------------------------------------------------------------------
% DCM         - Template DCM structure
% BPA.CQ      - BPA posterior covariance (full)
% BPA.Cq      - BPA posterior covariance (reduced)
% BPA.EQ      - BPA posterior mean (full)
% BPA.Eq      - BPA posterior mean (reduced)
% Pk          - Posterior probability of each parameter
% Pf          - Posterior probability of each family
% params      - User supplied parameters
% extra_plots - additional plots if there are no output arguments



if isstruct(DCM.Ep)
    i = spm_fieldindices(DCM.Ep,'A','B','C');
else
    i = 1:spm_length(DCM.Ep);
end