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_affine_priors.m
    path of file: ./repos/fieldtrip/external/spm12
    
    the code of the file until where you have to start completion: function [mu,isig] = spm_affine_priors(typ)
% Distribution of the priors used in affine registration
%
% The parameters for this distribution were derived empirically from 227
% scans, that were matched to the ICBM space.
%_______________________________________________________________________
% Copyright (C) 2003-2011 Wellcome Trust Centre for Neuroimaging

% John Ashburner
% $Id: spm_affine_priors.m 4155 2011-01-11 15:22:39Z guillaume $

%% Values can be derived by...
%sn = spm_select(Inf,'.*seg_inv_sn.mat$');
%X  = zeros(size(sn,1),12);
%for i=1:size(sn,1),
%    p  = load(deblank(sn(i,:)));

    
function [mu,isig] = spm_affine_priors(typ)
% Distribution of the priors used in affine registration
%
% The parameters for this distribution were derived empirically from 227
% scans, that were matched to the ICBM space.
%_______________________________________________________________________
% Copyright (C) 2003-2011 Wellcome Trust Centre for Neuroimaging

% John Ashburner
% $Id: spm_affine_priors.m 4155 2011-01-11 15:22:39Z guillaume $

%% Values can be derived by...
%sn = spm_select(Inf,'.*seg_inv_sn.mat$');
%X  = zeros(size(sn,1),12);
%for i=1:size(sn,1),
%    p  = load(deblank(sn(i,:)));
%    M  = p.VF(1).mat*p.Affine/p.VG(1).mat;
%    J  = M(1:3,1:3);
%    V  = sqrtm(J*J');
%    R  = V\J;
%    lV      =  logm(V);
%    lR      = -logm(R);
%    P       = zeros(12,1);
%    P(1:3)  = M(1:3,4);
%    P(4:6)  = lR([2 3 6]);
%    P(7:12) = lV([1 2 3 5 6 9]);
%    X(i,:)  = P';
%end