20171013, 09:08  #1 
Aug 2004
New Zealand
2·3·37 Posts 
Resume dependency processing?
I'm trying to factor the C195 cofactor of Pell(583) by SNFS using Yafu. All the sieving completed, linear algebra completed, and it produced a 51digit prime factor from dependency 2, but left a C145:
Code:
nfs: commencing msieve filtering 555109312683062119393323568281537098290442051919826633599191946398743120653033966337716794848068138895876548755215361212319751875346944966744570403598148867381515843660226447009202609523433561321 read 10M relations read 20M relations read 30M relations read 40M relations read 50M relations nfs: commencing msieve linear algebra linear algebra completed 5902018 of 5902337 dimensions (100.0%, ETA 0h 0m) nfs: commencing msieve sqrt NFS elapsed time = 524670.8332 seconds. ***factors found*** P51 = 336246287794168748415846490876768360738264937817769 C145 = 1650900940274080070056842767142908087541932084478741439796300957019264037849654528604010200642820006573008520577140256589131790152238203175660609 Code:
Fri Oct 13 20:45:07 2017 commencing square root phase Fri Oct 13 20:45:07 2017 reading relations for dependency 1 Fri Oct 13 20:45:08 2017 read 2950961 cycles Fri Oct 13 20:45:12 2017 cycles contain 8715406 unique relations Fri Oct 13 20:45:49 2017 read 8715406 relations Fri Oct 13 20:46:33 2017 multiplying 8715406 relations Fri Oct 13 20:51:29 2017 multiply complete, coefficients have about 222.00 million bits Fri Oct 13 20:51:30 2017 initial square root is modulo 92679589 Fri Oct 13 20:57:12 2017 GCD is 1, no factor found Fri Oct 13 20:57:12 2017 reading relations for dependency 2 Fri Oct 13 20:57:13 2017 read 2950151 cycles Fri Oct 13 20:57:17 2017 cycles contain 8716322 unique relations Fri Oct 13 20:57:54 2017 read 8716322 relations Fri Oct 13 20:58:37 2017 multiplying 8716322 relations Fri Oct 13 21:04:08 2017 multiply complete, coefficients have about 222.03 million bits Fri Oct 13 21:04:10 2017 initial square root is modulo 92925121 Fri Oct 13 21:10:56 2017 sqrtTime: 1549 
20171013, 13:56  #2 
"Victor de Hollander"
Aug 2011
the Netherlands
2^{3}·3·7^{2} Posts 
From the MSIEVE help "h"
try the "ncr" command to tell msieve to resume Linear Algebra from a checkpoint or "nc3" to only perform NFS square root Square root options: dep_first=x dep_last=y with x, y between 1 and 64 
20171013, 14:07  #3  
"Ben"
Feb 2007
2^{2}×23×37 Posts 
Quote:
Code:
else if (strcmp(opt,OptionArray[56]) == 0) { //argument "nc3". do nfs sqrt fobj>nfs_obj.nfs_phases = NFS_PHASE_SQRT; } 

20171013, 18:21  #4  
Aug 2004
New Zealand
336_{8} Posts 
Quote:
Code:
rwrwr 1 sean rtg 463 Sep 19 22:23 nfs.job rwrr 1 sean rtg 308 Oct 7 19:26 yafu.ini rwrwr 1 sean rtg 236097336 Oct 13 19:04 nfs.dat.bak.chk rwrwr 1 sean rtg 236097336 Oct 13 20:04 nfs.dat.chk I tried copying nfs.dat.chk to msieve.dat.chk and nfs.job to msieve.job and running msieve. But it does not find the polynomial when I try to start msieve: Code:
msieve nc3 3,5 555109312683062119393323568281537098290442051919826633599191946398743120653033966337716794848068138895876548755215361212319751875346944966744570403598148867381515843660226447009202609523433561321 error generating or reading NFS polynomials 

20171013, 18:34  #5  
"Victor de Hollander"
Aug 2011
the Netherlands
2^{3}·3·7^{2} Posts 
Quote:
C204_119_99.dat.gz (compressed relations from NFS@home) msieve.dat (uncompressed relations) msieve.dat.bak.chk (backup checkpoint) msieve.dat.chk (checkpoint) msieve.dat.cyc msieve.dat.dep msieve.dat.mat (matrix) msieve.fb msieve.poly (poly) msieve.projection (you dont need this file, its from NFS@home I believ) worktodo.ini (the to factor number goes in here) + some .dlls the .exe readme/changes since its a Windozzzz system 

20171013, 22:07  #6  
Basketry That Evening!
"Bunslow the Bold"
Jun 2011
40<A<43 89<O<88
3·29·83 Posts 
Quote:
However this is moot, as the "nfs.dat" (no trailing filename tags) relations file is indeed required for all steps. Linear algebra determines how to combine the relations into a congruence of squares, where the "sqrt" performs the actual combination found previously, and then deduces the factors. But in order to perform the combination of relations specified by the solved matrix, you do in fact need the relations in their entirety. If you cannot find the entire relations file somewhere, you will need to restart from scratch for the C145, unfortunately. Definitely not a fun bug in yafu. Last fiddled with by Dubslow on 20171013 at 22:08 

20171013, 23:56  #7  
"Ben"
Feb 2007
2^{2}·23·37 Posts 
Quote:


20171014, 02:30  #8  
Aug 2004
New Zealand
2·3·37 Posts 
Quote:


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