Thread: YAFU 2.0 View Single Post
2021-07-06, 15:36   #142
bsquared

"Ben"
Feb 2007

2·1,789 Posts

Quote:
 Originally Posted by charybdis Despite the recent changes to make poly selection faster, it still continues up until the deadline for most 109-digit numbers: Code: 07/05/21 07:12:47, nfs: commencing nfs on c109: 1090856851194159102847462612480990401998890638794326582448210291834957096186057950134759387351816485448746449 07/05/21 07:12:47, nfs: commencing poly selection with 6 threads 07/05/21 07:12:47, nfs: setting deadline of 2964 seconds 07/05/21 07:12:47, nfs: expecting degree 4 poly E from 3.14e-09 to > 3.62e-09 07/05/21 07:12:47, nfs: searching for avg quality poly E > 3.26e-09 07/05/21 08:04:29, nfs: completed 146 ranges of size 60 in 3102.7585 seconds 07/05/21 08:04:29, nfs: best poly = # norm 3.444816e-10 alpha -7.184646 e 1.363e-09 rroots 3 Notice the huge difference between the expected E values and what we actually get. For numbers between 10^108 and 2^362 (≈9.39*10^108), yafu thinks msieve will use degree 4 but it actually uses degree 5. So an "average" quality polynomial never turns up and the search continues until the deadline.
This is good to know, I will have to add a check to see what degree is actually being used.

Also, the bug you previously reported has been found and fixed (thanks for the detailed report!). I still need to commit the changes... hopefully will get a chance tonight.