Changeset e26667 in git

Timestamp:

May 2, 2012, 2:00:57 PM (11 years ago)

Author:

Martin Lee <martinlee84@…>

Branches:

(u'jengelh-datetime', 'ceac47cbc86fe4a15902392bdbb9bd2ae0ea02c6')(u'spielwiese', '0d6b7fcd9813a1ca1ed4220cfa2b104b97a0a003')

Children:

2156ec376c4c5977dc1fc4a9186651db3fdf492d

Parents:

59778389f5075553bef793320610ce298d74b18d

git-author:

Martin Lee <martinlee84@web.de>2012-05-02 14:00:57+02:00

git-committer:

Martin Lee <martinlee84@web.de>2012-05-07 14:17:00+02:00

Message:

chg: use cofactors in EZGCD to test divisibility

Location:

factory

Files:

• cf_gcd_smallp.cc (modified) (2 diffs)
• fac_ezgcd.cc (modified) (2 diffs)

factory/cf_gcd_smallp.cc

@@ -4628 +4628 @@
   }
 
-  CanonicalForm cand;
+  CanonicalForm cand, contcand;
   CanonicalForm result;
   int o, t;
@@ -4871 +4871 @@
       if (gcdfound == 1)
       {
-        cand = DD[2] / content( DD[2], Variable(1) );
-        gcdfound = fdivides( cand, G ) && fdivides ( cand, F ); //TODO use multiplication instead of fdivides
+        contcand= content (DD[2], Variable (1));
+        cand = DD[2] / contcand;
+        if (B_is_F)
+          gcdfound = fdivides( cand, G ) && cand*(DD[1]/(lcD/contcand)) == F;
+        else
+          gcdfound = fdivides( cand, F ) && cand*(DD[1]/(lcD/contcand)) == G;
 
         if (passToGF && gcdfound)

factory/fac_ezgcd.cc

@@ -414 +414 @@
   bool isRat= isOn (SW_RATIONAL);
   CanonicalForm F, G, f, g, d, Fb, Gb, Db, Fbt, Gbt, Dbt, B0, B, D0, lcF, lcG,
-                lcD, cand, result;
+                lcD, cand, contcand, result;
   CFArray DD( 1, 2 ), lcDD( 1, 2 );
   int degF, degG, delta, t, count, maxeval;
@@ -654 +654 @@
       if (gcdfound)
       {
-        cand = DD[2] / content( DD[2], Variable(1) );
-        gcdfound = fdivides( cand, G ) && fdivides ( cand, F );
+        contcand= content (DD[2], Variable (1));
+        cand = DD[2] / contcand;
+        if (B_is_F)
+          gcdfound = fdivides( cand, G ) && cand*(DD[1]/(lcD/contcand)) == F;
+        else
+          gcdfound = fdivides( cand, F ) && cand*(DD[1]/(lcD/contcand)) == G;
       }
       /// ---> A8 (gcdfound)