function y=etaylorw(t)
   error= 1e-8;
   y=0; term=1; ii=0;
   while ( term > (error/2))
       y    = y+term;
       term = (t * term)/(ii+1);
       fprintf('%8d %18.17f %18.17f\n',ii,term,y);
       ii=ii+1;
   end
  

% e**t  = 1 + t + t^2 /2! + ...
% a_n+1 = a_n  * t /(n+1);
%  term = term * t / (ii+1)  above
% t^n / n! = error i.e. (et/n)^n = error
% term  
