function [a, d, c, f] = EqData1(x, tag)
% Returns the values at x of the data a=a(x), d=d(x), c=c(x) and f=f(x) 
% in the differential equation D(-aDu)+dDu+cu=f.
% tag is a subdomain reference tag, which is not used in this example.
% 
  
 a=5; 
 d=0; 
 c=0; 
 f=1000*sin(x);
 
 