ss2des - (polynomial) state-space to descriptor form

Calling Sequence

S=ss2des(Sl)

S=ss2des(Sl,flag)

Parameters

• Sl : syslin list: proper or improper linear system.
• flag : character string "withD"
• S : list

Description

Given the linear system in state-space representation Sl (syslin list), with a D matrix which is either polynomial or constant, but not zero ss2des returns a descriptor system as list('des',A,B,C,0,E) such that:

Sl=C*(s*E-A)^(-1)*B
   

If the flag "withD" is given, S=list('des',A,B,C,D,E) with a D matrix of maximal rank.

Examples

s=poly(0,'s');
G=[1/(s+1),s;1+s^2,3*s^3];Sl=tf2ss(G);
S=ss2des(Sl)
S1=ss2des(Sl,"withD")
Des=des2ss(S);Des(5)=clean(Des(5))
Des1=des2ss(S1)
 

See Also

pol2des  tf2des  des2ss  

Author

F. D.; ;