des2tf

Arguments

sl

list (linear system in descriptor form)

Bfs, Bis

two polynomial matrices

chis

polynomial

S

rational matrix

Description

Given the linear system in descriptor form i.e. Sl=list('des',A,B,C,D,E), des2tf converts sl into its transfer function representation:

S=C*(s*E-A)^(-1)*B+D

Called with 3 outputs arguments des2tf returns Bfs and Bis two polynomial matrices, and chis polynomial such that:

S=Bfs/chis - Bis

chis is the determinant of (s*E-A) (up to a xcative constant);

Examples

s=poly(0,'s');
G=[1/(s+1),s;1+s^2,3*s^3];
Descrip=tf2des(G);Tf1=des2tf(Descrip)
Descrip2=tf2des(G,"withD");Tf2=des2tf(Descrip2)
[A,B,C,D,E]=Descrip2(2:6);Tf3=C*inv(s*E-A)*B+D

See also

• glever — inverse of matrix pencil
• pol2des — polynomial matrix to descriptor form
• tf2des — transfer function to descriptor
• ss2tf — conversion from state-space to transfer function
• des2ss — descriptor to state-space
• rowshuff — shuffle algorithm