Wrong "step" function answer

Hello everybody

I'm using Matlab to study basic control theory and I'm simulating the time-response of different order systems. For this I was told to use the "step" function to see the time-response of the system to a Heaviside input but the plot I get using it doesn't match the theorical graph. Here is the simple code used:

H=tf([0 1],[1 2 3]);

figure(2)

step(H)

The answer presented by Matlab is:

I tried re-installiing Matlab, but the problem is still there. I appreciate the help you could bring me Greeting SimD

[Rick Rosson]

Please type:

   which step -all

and post the results.

[Simon Duque T.]

Mr. Rick Rosson Here is the result you asked me to do, Im sorry I didnt see your comment sooner. Thanks for your answer

>> which step -all

C:\Program Files\MATLAB\R2013b\toolbox\control\ctrlobsolete\step.m

C:\Program Files\MATLAB\R2013b\toolbox\shared\controllib\engine\@DynamicSystem\step.m % DynamicSystem method

C:\Program Files\MATLAB\R2013b\toolbox\ident\ident\@iddata\step.m % iddata method

C:\Program Files\MATLAB\R2013b\toolbox\matlab\system\@system\step.m % system method

Answer 1

[Simon Duque T.]

Hello to the community I wasn't able to solve the problem of the wrong step answer that Matlab gave me. The only solution was to uninstall de program and delete every trace of the program in the computer, such as registry and preferences, and re-intall it. It took a while but it's finally working, thanks for the ones who tried to solve the problem. Greetings Simon

Answer 2

[Youssef Khmou]

According to the system you described, here the result i obtained :

[Simon Duque T.]

Exactly, that is the correct answer we all should get with matlab, but the problem is that my matlab gets the answer presented above. This could be the result of a wrong-functioning distribution of Matlab by the university, or maybe I messed uo the setting of some toolbox... I dont know Thanks for your answer

Answer 3

[Simon Duque T.]

Mr. Rick Rosson Here is the result you asked me to do, Im sorry I didnt see your comment sooner. Thanks for your answer

>> which step -all

C:\Program Files\MATLAB\R2013b\toolbox\control\ctrlobsolete\step.m

C:\Program Files\MATLAB\R2013b\toolbox\shared\controllib\engine\@DynamicSystem\step.m % DynamicSystem method

C:\Program Files\MATLAB\R2013b\toolbox\ident\ident\@iddata\step.m % iddata method

C:\Program Files\MATLAB\R2013b\toolbox\matlab\system\@system\step.m % system method