Re: [OctDev] control-2.3.51 released in package forum - please upload

[c.]

On 5 Jun 2012, at 11:34, Lukas Reichlin wrote:

> Well, the sign IS relevant. But the two state-space models are equivalent if 
> you can find a diagonal transformation matrix T with entries -1 and 1 such 
> that
> 
>       Aexp = T \ Aobs * T
>       Bexp = T \ Bobs
>       Cexp =     Cobs * T
>       Dexp =     Dobs
> 
> I don't know which ATLAS routine returns different solutions and why. If 
> there is such a T, then the result is not wrong in the sense of control 
> engineering.
> Using
>       assert (abs (Mo), abs (Me), 1e-4)
> i just a crutchm, we should find and test T.
> 
> BTW: M = [A, B; C, D

Thanks for the explanation. 
Are B and/or C above invertible?
what are their sizes?

c.