Christophe Oosterlynck wrote: > Hi, > > I was wondering on what algorithm the wiedemann implementation in / > devel/sage/sage/matrix/matrix2.pyx was based on. When looking at > Wiedemann's paper from '86, in which he describes a non-deterministic > and deterministic algorithm, it seems like the sage implementation > uses the deterministic algorithm. But in Sage there is a krylov > sequence being built using the iterate() matrix method, which gives > the sequence v, v*A, v*A^2... while in the original algorithm it > starts with using the sequence v, A*v, A²*v... > Any knows why or on what the wiedemann implementation is based on? I'm > trying to understand the wiedemann implementation because I need to > implement a modified block wiedemann implementation but I'm fairly new > to this kind of algebra.
I know nothing of the algorithm, but this looks like it might be an effect of left versus right operations? In Sage, things have typically been done "from the left" (i.e., kernel gives you a left kernel, etc.). Would that explain the difference? Jason --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
