st_ility(1)

NAME
st_ility - stabilizability test

CALLING SEQUENCE
[ns, [nc, [,U [,Slo] ]]]=st_ility(Sl [,tol])

PARAMETERS

Sl  : syslin list (linear system)

ns  : integer (dimension of stabilizable subspace)

nc  : integer (dimension of controllable subspace nc <= ns)

U   : basis such that its ns (resp. nc) first components span the stabilizable (resp. controllable) subspace

Slo : a linear system (syslin list)

tol : threshold for controllability detection (see contr)

DESCRIPTION
Slo=( U'*A*U, U'*B, C*U, D, U'*x0 ) (syslin list) displays the stabilizable form of Sl. Stabilizability means ns=nx (dim. of A matrix).
         [*,*,*]            [*]
U'*A*U = [0,*,*]     U'*B = [0]
         [0,0,*]            [0]
(where (A11,B1) is controllable and A22 is stable)

SEE ALSO
dt_ility, contr

AUTHOR
S. Steer INRIA 1988