 function [out]=fprint(ncase,neqn,t,u)
%
% Function fprint displays the numerical and
% exact solutions to the 2 x 2 ODE problem
%
% Return current value of independent variable
% (Matlab requires at least one return argument)
  out=t;
%
% Problem parameters
  a=5.5;
  b=4.5;
%
% Print a heading for the solution at t = 0 
  if(t<=0.0)
%
%   Label for ODE integrator
%
%   Fixed step modified Euler 
    if(ncase==1)
      fprintf('\n\n euler2a integrator\n\n');
% 
%   Variable step modified Euler
    elseif(ncase==2)
      fprintf('\n\n euler2b integrator\n\n');
%
%   Fixed step classical fourth order RK
    elseif(ncase==3)
      fprintf('\n\n rkc4a integrator\n\n');
%
%   Variable step classical fourth order RK 
    elseif(ncase==4)
      fprintf('\n\n rkc4b integrator\n\n');
%
%   Fixed step RK Fehlberg 45 
    elseif(ncase==5)		
      fprintf('\n\n rkc45a integrator\n\n');
%		
%   Variable step RK Fehlberg 45 
    elseif(ncase==6)
      fprintf('\n\n rkc45b integrator\n\n');
    end
%
% Heading
  fprintf('         t         u1         u2     u1-ue1     u2-ue2\n');
%
% End of t = 0 heading
  end
%
% Numerical and analytical solution output 

%   Exact solution eigenvalues
    e1=-(a-b);
    e2=-(a+b);
%
%   Analytical solution
    ue(1)=exp(e1*t)-exp(e2*t);
    ue(2)=exp(e1*t)+exp(e2*t);
%
%   Difference between exact and numerical solutions
    diff=u-ue;
%
%   Display the numerical and exact solutions, and their difference 
    fprintf('%10.2f %10.5f %10.5f %10.5f %10.5f \n',t,u,diff);
