% Sample problem of ARCHI manual.  The absolute error tolerance is set
% to 1e-9 to illustrate the use of options.  Also, it is necessary to
% use the InitialY option because the solution is not continuous at the
% initial point.

options = ddeset('AbsTol',1e-9,'InitialY',[0; 0]);
sol = dde23('exer6f',[1, 2],'exer6h',[0, 4],options);

plot(sol.x,sol.y)
title('Sample Problem of ARCHI Manual.')
xlabel('time t');
ylabel('y(t)');