first.m

为了下载东西

function z = first(v)
% First item in a vector
%
% function z = first(v)
%
% v   a vector
% z   first item of v
%     if v is empty, zero

% Jantzen 943003

 if isempty(v),
   z = 0 ;
 else,
   z = v(1);
 end ;