I've just been looking at SAGE ticket number 173: http://www.sagemath.org:9002/sage_trac/ticket/173
The idea is that Mathematica raises a 3 dimensional matrix M over QQ to the power 20,000 much faster than either SAGE or Magma. I don't know any algorithm for doing this efficiently. I only know one algorithm: 1) Compute the characteristic polynomial p(x) of M (time 0.00s) 2) Compute x^20000 mod p (time 0.22s) 3) Substitute M into the result (time 0.00s) It's pretty obvious where the time is going here - polynomial arithmetic. I guess this is the algorithm being used. Is Pari or NTL being used for the polynomial expmod? I reckon we can speed this up. What do people think? Bill. --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~----------~----~----~----~------~----~------~--~---
