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: pr_spm_vec.m
    path of file: ./repos/malini/Codes/deconvolution - model/spm8/marsbar-0.44/@mardo_5/private
    
    the code of the file until where you have to start completion: function [vX] = pr_spm_vec(varargin)
% vectorises a numeric, cell or structure array
% FORMAT [vX] = pr_spm_vec(X);
% X  - numeric, cell or stucture array[s]
% vX - vec(X)
%__________________________________________________________________________
%
% e.g.:
% spm_vec({eye(2) 3}) = [1 0 0 1 3]'
%__________________________________________________________________________
% Copyright (C) 2005 Wellcome Department of Imaging Neuroscience
 
% Karl Friston
% $Id: spm_vec.m 279 2005-11-08 19:11:28Z karl $

% initialise X and vX
%--------------------------------------------------------------------------

    
function [vX] = pr_spm_vec(varargin)
% vectorises a numeric, cell or structure array
% FORMAT [vX] = pr_spm_vec(X);
% X  - numeric, cell or stucture array[s]
% vX - vec(X)
%__________________________________________________________________________
%
% e.g.:
% spm_vec({eye(2) 3}) = [1 0 0 1 3]'
%__________________________________________________________________________
% Copyright (C) 2005 Wellcome Department of Imaging Neuroscience
 
% Karl Friston
% $Id: spm_vec.m 279 2005-11-08 19:11:28Z karl $

% initialise X and vX
%--------------------------------------------------------------------------
X     = varargin;
if length(X) == 1
    X = X{1};
end