Change input power as the model runs: 50 , Ambient 20

<![CDATA[ function setup(){ tmax = 200; demand=50; ambient=20; tank=ambient; a=0.1; b=7; dt = .1; ScaleWindow(-5,-5,tmax,110); DrawAxes(0,0,tmax,110); Label('Open loop',150,75); tank = 20; Colour("black"); t = 0; i=0; MoveTo(t,tank); loop(); } ]]>
<![CDATA[ function loop{ u=demand/100; tank=tank+(a*(ambient-tank)+b*u)*dt; tout=pipe[i]; pipe[i]=tank; i=i+1; if(i>99){i=0;} t = t + dt; Colour("red"); Spot(t, demand); Colour("black"); Spot(t, tout); if (t<tmax){ setTimeout('loop()',10); } } ]]>