Talk:Inverse iteration

Naming
Afaik this is also known as Wielandt iteration. Can somebody confirm these are indeed the same things? Can inverse iteration be attributed reliably to Wielandt?

Benefits of technique
"..inverse iteration is an iterative eigenvalue algorithm based on power iteration that achieves superior flexibility and performance. .."

Superior performance to what? Is there some upper/lower bound to compare this to? In this context, what would flexibility mean? Vonkje 3 July 2005 14:40 (UTC)


 * Superior performance when compared to power iteration, and flexibility means that you can choose which eigenvalue to converge to, while the power method always converges to the largest eigenvalue. To be honest, this all seems to be described pretty clearly in the article; can you suggest some reformulation to clarify? -- Jitse Niesen (talk) 3 July 2005 15:04 (UTC)


 * Not really. The article is otherwise well written except for the marketing terminology in the first sentence.  Now that you have clarified the specifics I would like to try my hand at a minor revision to that first sentence, probably by splitting it into two.  Vonkje 3 July 2005 21:35 (UTC)

If mu in an eigenvalue, then A - mu * id is, by definition not invertible
.. however, the article uses the expression (A - mu * id)^(-1) over and over. Obviously, this needs clarification.