hankelsv

Scilab Function

hankelsv - Hankel singular values

[nk2,W]=hankelsv(sl [,tol])

[nk2]=hankelsv(sl [,tol])

sl : syslin list representing the linear system (state-space).
tol : tolerance parameter for detecting imaginary axis modes (default value is 1000*%eps).

returns nk2, the squared Hankel singular values of sl and W = P*Q = controllability gramian times observability gramian.

nk2 is the vector of eigenvalues of W.

A=diag([-1,-2,-3]);
sl=syslin('c',A,rand(3,2),rand(2,3));[nk2,W]=hankelsv(sl)
[Q,M]=pbig(W,nk2(2)-%eps,'c');
slr=projsl(sl,Q,M);hankelsv(slr)