https://www.intel.com/content/www/us/en/docs/onemkl/developer-reference-fortran/2025-2/p-gehd2.html
p?gehd2
Reduces a general matrix to upper Hessenberg form by an orthogonal/unitary similarity transformation (unblocked algorithm).
p
https://www.intel.com/content/www/us/en/docs/onemkl/developer-reference-fortran/2023-2/p-gehd2.html
p?gehd2
Reduces a general matrix to upper Hessenberg form by an orthogonal/unitary similarity transformation (unblocked algorithm).
p