Changeset 14e634 in git for factory/facBivar.cc

Timestamp:

Dec 10, 2012, 3:38:49 PM (10 years ago)

Author:

Martin Lee <martinlee84@…>

Branches:

(u'jengelh-datetime', 'ceac47cbc86fe4a15902392bdbb9bd2ae0ea02c6')(u'spielwiese', 'a800fe4b3e9d37a38c5a10cc0ae9dfa0c15a4ee6')

Children:

b15cf8578937df382dad415dbfdd2229103409bf

Parents:

3e7db4d961b4509d248e12d8e96e2bed08d9cfe8

git-author:

Martin Lee <martinlee84@web.de>2012-12-10 15:38:49+01:00

git-committer:

Martin Lee <martinlee84@web.de>2012-12-12 15:24:58+01:00

Message:

fix: bug in factorization over Q(a)

File:

• factory/facBivar.cc (modified) (5 diffs)

factory/facBivar.cc

@@ -499 +499 @@
   modpk b= modpk();
   bool mipoHasDen= false;
+  CanonicalForm den= 1;
   if (!extension)
   {
@@ -519 +520 @@
   {
     A /= Lc (Aeval);
+    mipoHasDen= !bCommonDen(mipo).isOne();
+    mipo *= bCommonDen (mipo);
+    ZZX NTLmipo= convertFacCF2NTLZZX (mipo);
+    ZZX NTLLcf= convertFacCF2NTLZZX (Lc (A*bCommonDen (A)));
+    ZZ NTLf= resultant (NTLmipo, NTLLcf);
+    ZZ NTLD= discriminant (NTLmipo);
+    den= abs (convertZZ2CF (NTLD*NTLf));
+
     // make factors elements of Z(a)[x] disable for modularDiophant
     CanonicalForm multiplier= 1;
@@ -529 +538 @@
     A *= bCommonDen (A);
 
-    mipoHasDen= !bCommonDen(mipo).isOne();
-    mipo *= bCommonDen (mipo);
     Off (SW_RATIONAL);
     int i= 0;
-    ZZX NTLmipo= convertFacCF2NTLZZX (mipo);
-    CanonicalForm discMipo= convertZZ2CF (discriminant (NTLmipo));
+    CanonicalForm discMipo= convertZZ2CF (NTLD);
     findGoodPrime (F*discMipo,i);
     findGoodPrime (Aeval*discMipo,i);
@@ -555 +561 @@
   uniFactors= henselLiftAndEarly
               (A, earlySuccess, earlyFactors, degs, liftBound,
-               uniFactors, dummy, evaluation, b);
+               uniFactors, dummy, evaluation, b, den);
   TIMING_END_AND_PRINT (fac_bi_hensel_lift,
                         "time for bivariate hensel lifting over Q: ");
@@ -578 +584 @@
   TIMING_START (fac_bi_factor_recombination);
   factors= factorRecombination (uniFactors, A, MODl, degs, 1,
-                                uniFactors.length()/2, b);
+                                uniFactors.length()/2, b, den);
   TIMING_END_AND_PRINT (fac_bi_factor_recombination,
                         "time for bivariate factor recombination over Q: ");