des2tf

des2tf — descriptor to transfer function conversion

Calling sequence

[S]=des2tf(sl)  
[Bfs,Bis,chis]=des2tf(sl)  

Parameters

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, pol2des, tf2des, ss2tf, des2ss, rowshuff

Author

F. D.