unobs - unobservable subspace

Calling Sequence

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

Parameters

• 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  contrss  canon  cont_mat  spantwo  dt_ility