obs_gram

Arguments

A,C

real matrices (of appropriate dimensions)

dom

string ("d' or "c" (default value))

sl

syslin list

Description

Observability gramian of the pair (A,C) or linear system sl (syslin list). dom is the domain which can be

"c"

continuous system (default)

"d"

discrete system

Examples

A=-diag(1:3);C=rand(2,3);
Go=obs_gram(A,C,'c');     // <=> w=syslin('c',A,[],C); Go=obs_gram(w);
norm(Go*A+A'*Go+C'*C,1)
norm(lyap(A,-C'*C,'c')-Go,1)
A=A/4; Go=obs_gram(A,C,'d');    //discrete time case
norm(lyap(A,-C'*C,'d')-Go,1)

See also

• ctr_gram — controllability gramian
• obsvss — observable part
• obsv_mat — observability matrix
• lyap — Lyapunov equation