unobs

unobservable subspace

Calling Sequence

[n,[U]]=unobs(A,C,[tol])

Arguments

:A, C real matrices : :tol tolerance used when evaluating ranks (QR factorizations). : :n dimension of unobservable subspace. : :U orthogonal change of basis which puts (A,B) in canonical form. :

Description

[n,[U]]=unobs(A,C,[tol]) gives the unobservable form of an (A,C) pair. The n first columns of U make a basis for the unobservable subspace.

The (2,1) block (made of last nx-n rows and n first columns) of U’*A*U is zero and and the n first columns of C*U are zero.

Examples

A=`diag`_([1,2,3]);C=[1,0,0];
unobs(A,C)

See Also

• contr controllability, controllable subspace, staircase
• contrss controllable part
• canon canonical controllable form
• cont_mat controllability matrix
• spantwo sum and intersection of subspaces
• dt_ility detectability test