projspec(1)

NAME
projspec - spectral operators

CALLING SEQUENCE
[S,P,D,index]=projspec(A)

PARAMETERS

A   : square matrix

S, P, D
    : square matrices

index
    : integer

DESCRIPTION
Spectral characteristics of A at 0.

S = reduced resolvent at 0 (S = -Drazin_inverse(A)).

P = spectral projection at 0.

D = nilpotent operator at 0.

index = index of the 0 eigenvalue.

AUTHOR
F. D.