%non-stable, linear ODE
function dy = ode_def(t,y)
% define a simple ODE y'= y; 
    dy = y;
return;

%%stable, linear ODE
%function dy = ode_def(t,y)
%% define a simple ODE y'=-y; 
%    dy = -y;
%return;

%%stable, non-linear, dependant on t
%function dy = ode_def(t,y)
%% define a simple ODE y'=-2*t*y^2; 
%    dy = -2*t*y^2;
%return;

%%stiff ODE
%function dy = ode_def(t,y)
%% define a simple ODE y'=-100*y +100*t +101; 
%    dy = -100*y +100*t +101;
%return;