% Simulate/evaluate the system using its analytical solution. Typically, this is done by simulating the ODE using solvers such as ode15s, ode45, etc. Because this system is simple enough to allow an analytical solution, the simulation/evaluation is easy.
function obs = toy_system_evaluate(para,t)
if length(para)==2
para = para(:);
end
N = size(para,2);
for i=1:N
theta1 = para(1,i);
theta2 = para(2,i);
for j=1:length(t)
obs(j,i) = exp(-theta1*t(j)) + exp(-theta2*t(j));
end
end
end