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 Showing results 1 to 25 of 371 Search took 0.05 seconds. Search: Posts Made By: charybdis
 Forum: Factoring 2021-07-31, 12:37 Replies: 424 Views: 18,154 Posted By charybdis Done, along with a further 2100 curves at B1=4e8... Done, along with a further 2100 curves at B1=4e8 on the c179. Booking the c179 for GNFS.
 Forum: Miscellaneous Math 2021-07-30, 13:14 Replies: 20 Views: 768 Posted By charybdis Yes, it's heuristic, but why do you need a proof?... Yes, it's heuristic, but why do you need a proof? Integer factorization algorithms often have a probabilistic element to them: in the quadratic sieve, how do you know you're actually going to find...
 Forum: Miscellaneous Math 2021-07-29, 19:55 Replies: 20 Views: 768 Posted By charybdis Going back to this: Please can you... Going back to this: Please can you explain, in full, what your algorithm actually is for higher n? You haven't made it clear which of the squares stay as squares and which change to n-th...
 Forum: Miscellaneous Math 2021-07-29, 18:48 Replies: 20 Views: 768 Posted By charybdis Try going through the same calculations that I... Try going through the same calculations that I did, but with n=3 and the square roots replaced with cube roots. Can you see where things change?
 Forum: Factoring 2021-07-29, 18:08 Replies: 424 Views: 18,154 Posted By charybdis Speaking of GNFS targets, I'll run t55 on the... Speaking of GNFS targets, I'll run t55 on the c179 and c182 from (7,-8).
 Forum: Miscellaneous Math 2021-07-29, 02:22 Replies: 20 Views: 768 Posted By charybdis Write [$]\left\lceil \sqrt{b^2-a}... Write [$]\left\lceil \sqrt{b^2-a} \right\rceil[/$] as [$]\sqrt{b^2-a}+\epsilon[/$], where [$]\epsilon[/\$] is between 0 and 1. Let's see what happens when we square this. We get...
 Forum: CADO-NFS 2021-07-25, 23:12 Replies: 15 Views: 391 Posted By charybdis Aaargh, I was hoping this wouldn't happen. I... Aaargh, I was hoping this wouldn't happen. I believe this is a genuine bug. I've seen it on a couple of GNFS jobs recently and was hoping to gather some more data on when it occurs before reporting...
 Forum: CADO-NFS 2021-07-25, 20:35 Replies: 15 Views: 391 Posted By charybdis It looks like grep is abruptly stopping partway... It looks like grep is abruptly stopping partway through the file. It also looks like you haven't added -o to the grep command. Can you try with -ao instead?
 Forum: CADO-NFS 2021-07-25, 20:17 Replies: 15 Views: 391 Posted By charybdis That's what I was trying to explain how to do... That's what I was trying to explain how to do here: Of course you'll need grep to work properly in order to do this. I inserted your line into one of my old logfiles and grep found it...
 Forum: CADO-NFS 2021-07-25, 19:50 Replies: 15 Views: 391 Posted By charybdis dup1.1.0000.gz should be created by the second... dup1.1.0000.gz should be created by the second dup1 run - confusingly, CADO isn't consistent on whether to start its indexing at 0 or 1. Assuming you did run dup1 a second time, what are the contents...
 Forum: CADO-NFS 2021-07-25, 18:09 Replies: 15 Views: 391 Posted By charybdis So you don't have a file... So you don't have a file c212_snfs215.dup1.filelist.1? That's odd, it obviously existed when the command ran originally, and it doesn't usually get deleted during the run. If you definitely have...
 Forum: CADO-NFS 2021-07-25, 16:46 Replies: 15 Views: 391 Posted By charybdis This cannot have been the first dup1 command: the... This cannot have been the first dup1 command: the .3 endings on the files mean that it was the third. Try emptying the dup1 folder and trying again from the start; make sure you look back far enough...
 Forum: CADO-NFS 2021-07-25, 14:31 Replies: 15 Views: 391 Posted By charybdis Re-create the directory... Re-create the directory /tmp/cado.v9x5al17/c212_snfs215.dup1, and make subdirectories named 0 and 1 inside it. Re-run all of the dup1 and dup2 commands in the c212_snfs215.cmd file in order. If...
 Forum: Factoring 2021-07-22, 16:28 Replies: 424 Views: 18,154 Posted By charybdis So you ran t50 and then called yafu factor(),... So you ran t50 and then called yafu factor(), which presumably ran at least another t50?
 Forum: Factoring 2021-07-22, 14:59 Replies: 424 Views: 18,154 Posted By charybdis Ah, so by preNFS you really mean the first stage... Ah, so by preNFS you really mean the first stage of NFS. I suppose if we're being really strict about the meaning of the word "sieve" then polynomial selection is pre-NFS and postprocessing is...
 Forum: Factoring 2021-07-22, 13:59 Replies: 424 Views: 18,154 Posted By charybdis What do you mean by "preNFS"? What do you mean by "preNFS"?
 Forum: Factoring 2021-07-22, 12:17 Replies: 424 Views: 18,154 Posted By charybdis As an SNFS job this is probably equivalent to a... As an SNFS job this is probably equivalent to a GNFS in the low 160s. I've seen a few different estimates for ECM effort but for GNFS I usually go for c*digits with c = 0.31 or 0.32. For this number,...
 Forum: Factoring 2021-07-21, 22:40 Replies: 521 Views: 97,850 Posted By charybdis A rather lucky ECM factor from aliquot sequence... A rather lucky ECM factor from aliquot sequence 2360: Using B1=11000000, B2=35133391030, polynomial Dickson(12), sigma=1:2026970909 Step 1 took 12373ms Step 2 took 5994ms ********** Factor...
 Forum: CADO-NFS 2021-07-21, 11:37 Replies: 18 Views: 499 Posted By charybdis The advantage for adjust_strategy=2 with integer... The advantage for adjust_strategy=2 with integer I seems to get greater for larger jobs. I don't know why this happens, but it does. So if you're doing a big job then you definitely will want...
 Forum: CADO-NFS 2021-07-20, 18:59 Replies: 18 Views: 499 Posted By charybdis tasks.I = n corresponds to tasks.A = 2n-1, so... tasks.I = n corresponds to tasks.A = 2n-1, so A=26 is between I=13 and I=14. If you're using an even value of A, you should use adjust_strategy = 2 whatever the circumstances. For tasks.I (in...
 Forum: CADO-NFS 2021-07-20, 17:42 Replies: 18 Views: 499 Posted By charybdis The E-score is supposed to be directly... The E-score is supposed to be directly proportional to yield for a fixed set of parameters, so you'd expect the number with the lower score here to take about 70% longer if the parameters remain the...
 Forum: CADO-NFS 2021-07-20, 13:19 Replies: 18 Views: 499 Posted By charybdis It was the 4-digit increase in GNFS equivalent... It was the 4-digit increase in GNFS equivalent difficulty for a 3-digit increase in SNFS difficulty that surprised me. Judging by the E scores of the polynomials, I would have expected them to sieve...
 Forum: Aliquot Sequences 2021-07-19, 16:47 Replies: 2,972 Views: 235,673 Posted By charybdis I'd say go ahead. After all, a journey of a... I'd say go ahead. After all, a journey of a thousand miles begins with a single step (or rather 12,000 steps...)
 Forum: CADO-NFS 2021-07-19, 16:38 Replies: 18 Views: 499 Posted By charybdis That's surprising. Can you post the params files... That's surprising. Can you post the params files you used for each of these jobs? The number of relations required is determined mainly by lpb0/lpb1: raising both by 1 roughly doubles the...
 Forum: CADO-NFS 2021-07-19, 13:40 Replies: 18 Views: 499 Posted By charybdis Unfortunately it's not linear. It depends on the... Unfortunately it's not linear. It depends on the degree of the polynomial and which side you're sieving on (which reminds me: -sqside is another important optional command line flag for las), and...
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