Custom periodic function without counter

Question

I am using ode45 to solve a simple ODE:

function dCdt=u_vent(t,C)
if t>   600 &&  t<= 720
    Q=Q2;               
elseif t>   1320         


        

Answer 1

If you have the Signal Processing Toolbox, you can use something like:

>> t = 0:3600;
>> y = pulstran(t,[660:720:3600],'rectpuls',120);
>> plot(t,y)
>> ylim([-0.1 1.1])

which gives the following (in Octave, should be the same in MATLAB):

You then need to scale y to be between Q1 and Q2 instead of 0 and 1.