% ISFIELD ISFIELD Test for Existence of a Structure Field
% 
% Usage
% 
% Given a structure array, tests to see if that structure
% array contains a field with the given name.  The syntax
% for its use is
% 
%   y = isfield(x,field)
% 
% and returns a logical 1 if x has a field with the 
% name field and a logical 0 if not.  It also returns
% a logical 0 if the argument x is not a structure array.

% Copyright (c) 2002-2006 Samit Basu

function y = isfield(x,field)
  if (isa(x,'struct'))
    y = any(strcmp(fieldnames(x),field));
  else
    y = logical(0);
  end
