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: CBIG_ArealMSHBM_cMSHBM_estimate_group_priors_child.m
    path of file: ./repos/CBIG/stable_projects/brain_parcellation/Kong2022_ArealMSHBM/step2_estimate_priors
    
    the code of the file until where you have to start completion: function CBIG_ArealMSHBM_cMSHBM_estimate_group_priors_child(s, mesh, tmp_dir)

% CBIG_ArealMSHBM_cMSHBM_estimate_group_priors_child(s, mesh, 
    
function out = Cdln(k,d,k0)

% Computes the logarithm of the partition function of vonMises-Fisher as
% a function of kappa

k = double(k);

sizek = size(k);
k = k(:);

out = (d/2-1).*log(k)-log(besseli((d/2-1)*ones(size(k)),k));
if(d<1200)
    k0 = 500;
elseif(d>=1200 && d<1800)
    k0 = 650;
else
    error('dimension is too high, need  to specify k0');
end