Talk:Lanczos approximation

TO DO:

• Complete derivation
• Spouge's version
• Section on choice of g and error estimates
• Better ways to calculate A
  • Use of partial fraction decomposition
  • Integer matrices
• Mention corollary at the end of Lanczos paper

Fredrik | tc 10:15, 13 January 2006 (UTC)

arbitrary precision?

I don't believe that lanczos can be used for arbitrary precision because it is a single asymptotic expansion and is thus subject to divergence due to stoke's phenomenon. Does anyone have evidence that it is suitable for arbitrary precision? --njh 04:34, 13 June 2006 (UTC)

Lanczos Coefficients

My question is about correctly interpreting the Lanczos approximation's Coefficients formula.That is the pk(g) formula that begins with a Sum sign in the Coefficients section. Does that formula run only along the bottom line of the triangular coefficient matrix, as suggested by the "a= 0 to k" spec ? If it did, then only one coefficient could be calculated. So it seems to me that each coefficient is obtained by applying that formula to one particular odd row. For example, coefficient P0 would relate to row one only, P1 to row 3 only, .....Pk to row k (last one) only. Can some fan of Lanczos give me some help on this ? Chambala (talk) 00:44, 1 April 2010 (UTC)User Camille Milot March 31, 2010 20:42 Canadian EasternDayligntTimeChambala (talk) 00:44, 1 April 2010 (UTC)