companion matrix
A=companion(p)
polynomial or vector of polynomials
square matrix
Returns a matrix A
with characteristic polynomial equal
to p
if p
is monic. If p
is not monic
the characteristic polynomial of A
is equal to
p/c
where c
is the coefficient of largest degree
in p
.
If p
is a vector of monic polynomials, A
is block diagonal,
and the characteristic polynomial of the ith block is p(i)
.