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: pos2dim.m
    path of file: ./repos/PsPM/src/Import/fieldtrip/fileio/private
    
    the code of the file until where you have to start completion: function [dim] = pos2dim(pos)

% POS2DIM reconstructs the volumetric dimensions from an ordered list of 
% positions.
%
% Use as
%   [dim] = pos2dim(pos)
% where pos is an ordered list of positions.
%
% The output dim is a 3-element vector which correspond to the 3D 
% volumetric dimensions

    
function [dim] = pos2dim(pos)

% POS2DIM reconstructs the volumetric dimensions from an ordered list of 
% positions.
%
% Use as
%   [dim] = pos2dim(pos)
% where pos is an ordered list of positions.
%
% The output dim is a 3-element vector which correspond to the 3D 
% volumetric dimensions
%
% See also POS2TRANSFORM

% Copyright (C) 2009, Jan-Mathijs Schoffelen

if isstruct(pos)
  % the input is a FieldTrip data structure
  pos = pos.pos;
end