Igor Schein on Mon, 19 Aug 2002 10:30:57 -0400 |
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Re: bnrL1() bug |
On Mon, Aug 19, 2002 at 02:32:32PM +0200, Karim Belabas wrote: > [Xavier] > > did I miss the email about the fix for this bug: > > Hi, > > I have temporarily lost access to my main accounts (ssh misconfigured, > presumably) and I've done a lot of work with CVS from my home machine, before > noticing I couldn't announce my changes [ I'm stealing an email account for > this answer, I saw your message by checking the pari-dev archive. I've no > access to my mailbox... ]. > > Quick list (hopefully, I'll be able to elaborate in a few days): > > * setrand(1);rnfkummer(bnrinit(bnfinit(quadpoly(4760,y)),23,1),matdiagonal([3,1,1])) --> 0 > > --> very tough bug. It's the first recorded instance of bnfinit actually > giving a wrong answer because we cheat on Bach's constant [ should be 12 > log^2 D under GRH, we use 0.3 log^2 D ]. Namely: > > setrand(3); bnfinit(y^4 + 1190*y^2 + 1416100).cyc > --> [8, 2, 2, 2] \\ WRONG > > setrand(3); bnfinit(y^4 + 1190*y^2 + 1416100,,[0.6]).cyc,,[0.6]).cyc > --> [8, 4, 2] \\ OK > > Trivial to correct [ use correct bound! ], BUT would slow down immensely most > bnfinit computations ! Certifying the result (bnfcertify) is not an option > either. OK, here's another one: ? setrand(4);rnfkummer(bnrinit(bnfinit(quadpoly(5288,y)),9,1),[1,0;0,3]); *** bug in GP (Segmentation Fault), please report ? Is it related to the same bnfinit() problem? Thanks Igor