arhnk - Hankel norm approximant

Calling Sequence

[slm]=arhnk(sl,ord,[tol])

Parameters

• sl : linear system (syslin list)
• ord : integer, order of the approximant
• tol : threshold for rank determination in equil1

Description

computes slm, the optimal Hankel norm approximant of the stable continuous-time linear system sl with matrices [A,B,C,D].

Examples

A=diag([-1,-2,-3,-4,-5]);B=rand(5,1);C=rand(1,5);
sl=syslin('c',A,B,C);
slapprox=arhnk(sl,2);
[nk,W]=hankelsv(sl);nk
[nkred,Wred]=hankelsv(slapprox);nkred
 

See Also

equil  equil1  hankelsv