Thread: YAFU 2.0
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Old 2021-07-06, 15:36   #142
bsquared's Avatar
Feb 2007

2·1,789 Posts

Originally Posted by charybdis View Post
Despite the recent changes to make poly selection faster, it still continues up until the deadline for most 109-digit numbers:

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.
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