Hessenberg form
H = hess(A) [U,H] = hess(A)
real or complex square matrix
real or complex square matrix
orthogonal or unitary square matrix
[U,H] = hess(A)
produces a unitary matrix
U
and a Hessenberg matrix H
so that
A = U*H*U'
and U'*U
=
Identity. By itself, hess(A)
returns H
.
The Hessenberg form of a matrix is zero below the first subdiagonal. If the matrix is symmetric or Hermitian, the form is tridiagonal.
hess function is based on the Lapack routines DGEHRD, DORGHR for real matrices and ZGEHRD, ZORGHR for the complex case.
hess
function is based on the Lapack routines
DGEHRD, DORGHR for real matrices and ZGEHRD, ZORGHR for the
complex case.