Ltiview and negative step response of a linear system

[dRic2]

Hi, my professor gave me I code where he used to evaluate the answer of a linear system to a step increase in the input variables like this:

MySystem = ss(A, B, C, D);
ltiveiw('step', MySystem, 'r-', 300);

My problem is that with this code I get the response only for a positive step. I'd like to see what happens for a negative step as well, but I can't figure out how to do it.

Thanks
Ric

 

[jedishrfu]

Check the MathWorks site on these functions you might spot something to help you there.

I did find this reference creating a state space that is input to the lti view function

https://www.mathworks.com/help/control/ref/ss.html
This may be where you can define your params.

If not check with your prof if possible.

 

[dRic2]

Thanks, I'll keep searching.

(ended up using SimuLink)

 

[FactChecker]

If the system is linear, the response to a negative step is the negation of the response to a positive step of the same size.