fineta(1)

NAME
fineta - reduced pencil

CALLING SEQUENCE
[Er,Ar,Q,Z]=fineta(F)
[Er,Ar,Q,Z]=fineta(E,A)

PARAMETERS

F   : real matrix pencil F=s*E-A

E,A : two real matrices of same dimensions

Q,Z : two orthogonal matrices (not necessarily square)

Er,Ar
    : two real matrices of same dimensions (reduced pencil)

DESCRIPTION
Returns the finite + eta part of the pencil F=sE-A.

Er=Q*E*Z, Ar=Q*A*Z has only finite and eta Kronecker invariants and Er is full column rank.

Q : left (row)-subspace associated with finite and eta part of the pencil

For a regular pencil Q spans the left finite eigenspace.

AUTHOR
F. D & R. N.

SEE ALSO
kroneck, pencan, epsfin