des2ss

descriptor to state-space

Calling Sequence

[Sl]=des2ss(A,B,C,D,E [,tol])
[Sl]=des2ss(Des)

Arguments

:A,B,C,D,E real matrices of appropriate dimensions : :Des list : :Sl syslin list : :tol real parameter (threshold) (default value 100*%eps). :

Description

Descriptor to state-space transform.

Sl=des2ss(A,B,C,D,E) returns a linear system Sl equivalent to the descriptor system (E,A,B,C,D).

For index one (E,A) pencil, explicit formula is used and for higher index pencils rowshuff is used.

Sl=des2ss(Des) with Des=list(‘des’,A,B,C,D,E) returns a linear system Sl in state-space form with possibly a polynomial D matrix.

A generalized Leverrier algorithm is used.

Examples

s=`poly`_(0,'s');G=[1/(s-1),s;1,2/s^3];
S1=`tf2des`_(G);S2=`tf2des`_(G,"withD");
W1=des2ss(S1);W2=des2ss(S2);
`clean`_(`ss2tf`_(W1))
`clean`_(`ss2tf`_(W2))

See Also

• des2tf descriptor to transfer function conversion
• glever inverse of matrix pencil
• rowshuff shuffle algorithm