Changeset 6594d4 in git

Timestamp:

Sep 23, 1998, 7:07:45 PM (25 years ago)

Author:

Jens Schmidt <schmidt@…>

Branches:

(u'spielwiese', 'f6c3dc58b0df4bd712574325fe76d0626174ad97')

Children:

073d2edeb03013a5c6ed0913687b024305a1427d

Parents:

7709bf1f0117c77f62572e798d2164f8f0a773a4

Message:

	* fac_ezgcd.cc (ezgcd_specialcase): bug fix (???).  See comments
	  in the file for more information.


git-svn-id: file:///usr/local/Singular/svn/trunk@2515 2c84dea3-7e68-4137-9b89-c4e89433aadc

File:

• factory/fac_ezgcd.cc (modified) (2 diffs)

factory/fac_ezgcd.cc

@@ -1 +1 @@
 /* emacs edit mode for this file is -*- C++ -*- */
-/* $Id: fac_ezgcd.cc,v 1.11 1998-03-12 14:30:50 schmidt Exp $ */
+/* $Id: fac_ezgcd.cc,v 1.12 1998-09-23 17:07:45 schmidt Exp $ */
 
 #include <config.h>
@@ -159 +159 @@
     DEBOUTLN( cerr, "ezgcdspec: (S1)" );
     Ft = ezgcd( F, F.deriv( x ) );
+    if ( Ft.isOne() ) {
+        // In this case F is squarefree and we came here by bad chance
+        // (means: bad evaluation point).  Try again with another
+        // evaluation point.  Bug fix (?) by JS.  The bad example was
+        // gcd.debug -ocr /+USE_EZGCD/@12/CB \
+        //     '(16*B^8-208*B^6*C+927*B^4*C^2-1512*B^2*C^3+432*C^4)' \
+        //     '(4*B^7*C^2-50*B^5*C^3+208*B^3*C^4-288*B*C^5)'
+        b.nextpoint();
+        return ezgcd( F, G, b, true );
+    }
+            
     DEBOUTLN( cerr, "ezgcdspec: (S1) done, Ft = " << Ft );
     L = F / Ft;
     /// ---> S2
     DEBOUTLN( cerr, "ezgcdspec: (S2)" );
+
     L = ezgcd( L, G, b, true );
     DEBOUTLN( cerr, "ezgcdspec: (S2) done, Ds = " << Ds );