Igor Schein on Thu, 9 Oct 2003 15:17:53 -0400 |
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Re: polredabs failure |
On Thu, Oct 09, 2003 at 09:04:42PM +0200, Karim BELABAS wrote: > On Thu, 9 Oct 2003, Igor Schein wrote: > > ? p1=x^16-4*x^15-20*x^14+80*x^13+138*x^12-712*x^11+736*x^10+1200*x^9-8138*x^8+9288*x^7+1904*x^6-25248*x^5+73988*x^4-19184*x^3+41192*x^2+69456*x+30724; > > ? p2=x^16 + 66*x^12 + 3627*x^8 + 48114*x^4 + 531441; > > ? p1==polredabs(p1) > > 1 > > \\ p1 already *reduced* > > ? poldegree((v=polcompositum(p1,p2))[#v]) > > 16 > > \\ isomorphic > > ? norml2(polroots(p1)) > > 91.81780460041328907655758261 > > ? norml2(polroots(p2)) > > 87.63560920082657815311516524 > > \\ so we should have polredabs(p1)==p2 > > A complicated typo. The smallest element was found, then deleted due to a typo > which assessed to it the norm of another (larger) element, during the > "Sorting" phase (when there are too many small vectors, the list overflows, > and we need to discard some of them). Fixed in CVS. Immediate regression: ? allocatemem() *** Warning: doubling stack size; new stack = 8000000 (7.629 Mbytes). ? polredabs(x^16-4*x^15+16*x^13-48*x^11+16*x^10-32*x^9+360*x^8-616*x^7+352*x^6-112*x^3+96*x^2-32*x+4) *** bug in GP (Segmentation Fault), please report Thanks Igor