Re: convergence of QR-algorithm

From: hansm (mittelmann_at_asu.edu)
Date: 03/23/05 

Date: 23 Mar 2005 15:28:12 -0800

Hi,
you say you need "usually less than 10 iterations" per eigenvalue. For
general real matrices with the Francis shift you need on average 1.5 of
these double-steps and with alternative single shifts in case of
convergence to real eigenvalues you can speed it up some more etc etc.
But your goal is more simplicity of the program and robustness and not
absolute efficiency.
Hans Mittelmann