>[y,t] = step(sys,opt); Why must we do smth like that?
You don't have to do that. You can choose both way, with [y, t], or without [y, t].
- if you choose with [y, t], step() gives you "Step Response Data", and it does not give you "Step Response Plots".
- if you choose without [y, t], step() gives you "Step Response Plots", and it does not give you "Step Response Data".
You might see this example, but [y,t] = step(sys,opt); can be replaced with step(sys,opt);. You will get plot instead of [t, y] data.
opt = stepDataOptions('InputOffset',-1,'StepAmplitude',2);
[y,t] = step(sys,opt);
>But why must we write (t,y) in the plot while we define [y,t]?
Plot() is process for plot only and does not care about step function. So it needs (t, y) for data plot. If you choose step() without [y, t], you don't need using plot().
