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: surfedge.m
    path of file: ./repos/iso2mesh
    
    the code of the file until where you have to start completion: function [openedge,elemid]=surfedge(f,varargin)
%
% [openedge,elemid]=surfedge(f)
%
% find the edge of an open surface or surface of a volume
%
% author: Qianqian Fang, <q.fang at neu.edu>
% date: 2007/11/21
%
% input:
%      f: input, surface face element list, dimension (be,3)
%
% output:
%      openedge: list of edges of the specified surface

    
function [openedge,elemid]=surfedge(f,varargin)
%
% [openedge,elemid]=surfedge(f)
%
% find the edge of an open surface or surface of a volume
%
% author: Qianqian Fang, <q.fang at neu.edu>
% date: 2007/11/21
%
% input:
%      f: input, surface face element list, dimension (be,3)
%
% output:
%      openedge: list of edges of the specified surface
%      elemid (optional): the corresponding index of the 
%                tetrahedron of an open-edge or triangle, 
%                elemid has the same length as openedge.
%
% -- this function is part of iso2mesh toolbox (http://iso2mesh.sf.net)
%

if(isempty(f))
    openedge=[];
    return;
end