clear;

model_name = "rc_circuit";

stopTime = 5;
V_in = 10;
R = 1e3;
C = 1e-4;
freq = 1;
timestep = 0.01;

ts = (0:timestep:stopTime)';
vs = sin(2*pi*freq * ts);

sim_in = Simulink.SimulationInput(model_name);
% Note: the following has effect only if the system mask has been created
% for the settable parameters.
% Using Simulink.Parameter(R) in the above doesn't work.
sim_in = sim_in.setModelParameter("R", num2str(R));

% for model workspace variables, it's important to specifiy the workspace
% it's not necessary for the variable to be in the mask or to be argument
sim_in = sim_in.setVariable("C", C, Workspace=model_name);
sim_in = sim_in.setModelParameter("StopTime", num2str(stopTime));

% note: to be compatible with port size, ts must be a column vector
sim_in = sim_in.setExternalInput([ts, vs]);

% simulate
res = sim(sim_in);

figure;
subplot(2, 1, 1);
plot(ts, vs);
xlabel('Time (seconds)');
ylabel('V_{in} (Volt)');

subplot(2, 1, 2);
plot(res.yout{1}.Values);