On Dec 18, 2009, at 2:42 PM, John Cremona wrote: > 2009/12/18 Robert Bradshaw <rober...@math.washington.edu>: >> On Dec 18, 2009, at 2:20 PM, John Cremona wrote: >> >>> That looks brilliant. I think it would be fine to have the faster >>> version in unreadable mpfr provided that the "real" formula was >>> included as comments. >>> >>> Robert, can you post some version of what you have so far so I can >>> see >>> how you have made it faster? >> >> Essentially, I used double complex values--the code otherwise looks >> pretty much the same. I'll be putting it up on trac shortly. > > Hmmm -- it's not so great to have the speedup if it's not > multi-precision. The AGM algorithm is doubly exponential (i.e. the > number of correct digits doubles with each iteration) so in > single/double precision you hardly even need to have a loop. > Obviously that's still useful, as long as we have a multi version as > well.
Yeah, sorry if I wasn't clear about this. For such low precision, the overhead kills you and so I thought passing to CDF would be good. For higher precision, at least some of the time in the code will be spent doing "real work." - Robert -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
