.Modelica_LinearSystems2.Math.Matrices.Internal.hessenberg2

Information

This function computes the Hessenberg matrix of matrix A by repetitive application of Householder similarity transformation

    Ai+1 = (I-2*u_i*u_i')*Ai*(I-2*u_i*u_i')

with Householder vector u_i.

The elementary transformations can be subsumed under

   A -> Q*A*Q

and Q*A*Q is Hessenberg matrix.

In contrast to function Modelica_LinearSystems2.Math.Matrices.hess, function Modelica_LinearSystems2.Math.Matrices.hess3 does not use any LAPACK routine.

Interface

function hessenberg2
  extends Modelica.Icons.Function;
  import Modelica_LinearSystems2.Math.Matrices;
  import Modelica_LinearSystems2.Math.Vectors;
  input Real H[:, :];
  input String s = "u";
  output Real Ht[size(H, 1), size(H, 2)];
end hessenberg2;