When simulating the response to a specific input signal, the input data U must be a matrix of numeric values with at least two rows (samples) and without any NaN or Inf.

lsim( SS, [2;0.2], t)

this is the code ss is a state space model with 2 inputs and t is 0:0.4:10

Answer 1

[Ameer Hamza]

'u' must have as many rows as the number of elements in 't'. It seems that you want to apply step inputs. Try something like this

t = 0:0.4:10;
u = repmat([2, 0.2], numel(t), 1);
lsim(SS, u, t);

[khaled elmoshrefy]

Thank you so much ! it worked but i don't get what happened i am assuming i gave two rows of input as my model needs?

[Ameer Hamza]

You need to specify it as two columns. The number of rows should be the same as the number of elements in t. u is like this

u = [
    2 0.2;
    2 0.2;
    ..
    ..
    2 0.2]; % rows same as numel(t)

[khaled elmoshrefy]

Yeah i searched for these functions on mathworks. It goes like you said ,thanks