pfss - partial fraction decomposition
Partial fraction decomposition of the linear system Sl (in state-space form, transfer matrices are automatically converted to state-space form by tf2ss ):
elts is the list of linear systems which add up to Sl i.e. elts=list(S1,S2,S3,...,Sn) with:
Sl = S1 + S2 +... +Sn .
Each Si contains some poles of S according to the block-diagonalization of the A matrix of S .
For non proper systems the polynomial part of Sl is put in the last entry of elts .
If Sl is given in transfer form, it is first converted into state-space and each subsystem Si is then converted in transfer form.
The A matrix is of the state-space is put into block diagonal form by function bdiag . The optional parameter rmax is sent to bdiag . If rmax should be set to a large number to enforce block-diagonalization.
If the optional flag cord='c' is given the elements in elts are sorted according to the real part (resp. magnitude if cord='d' ) of the eigenvalues of A matrices.
W=ssrand(1,1,6); elts=pfss(W); W1=0;for k=1:size(elts), W1=W1+ss2tf(elts(k));end clean(ss2tf(W)-W1)
F.D.;