nlev

Arguments

A

real square matrix

z

character string

rmax

optional parameter (see bdiag)

Description

[num,den]=nlev(A,z [,rmax]) computes (z*eye()-A)^(-1)

by block diagonalization of A followed by Leverrier's algorithm on each block.

This algorithm is better than the usual leverrier algorithm but still not perfect!

Examples

A=rand(3,3);x=poly(0,'x');
[NUM,den]=nlev(A,'x')
clean(den-poly(A,'x'))
clean(NUM/den-inv(x*eye()-A))

See also

• coff — resolvent (cofactor method)
• coffg — Co-factors of a matrix of polynomials or rationals
• glever — inverse of matrix pencil
• ss2tf — conversion from state-space to transfer function