Changeset 498648 in git for factory/cf_chinese.cc

Timestamp:

Jun 27, 2011, 4:20:53 PM (12 years ago)

Author:

Martin Lee <martinlee84@…>

Branches:

(u'jengelh-datetime', 'ceac47cbc86fe4a15902392bdbb9bd2ae0ea02c6')(u'spielwiese', '00e2e9c41af3fde1273eb3633f4c0c7c3db2579d')

Children:

29179092d0c3ba3d252b203cd763be600dd7b096

Parents:

2ae57ff78cd82da1abf9ba52505c9ea78709e89c

Message:

rational reconstruction via NTL


git-svn-id: file:///usr/local/Singular/svn/trunk@14308 2c84dea3-7e68-4137-9b89-c4e89433aadc

File:

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

factory/cf_chinese.cc

@@ -20 +20 @@
 #include "cf_iter.h"
 
+#ifdef HAVE_NTL
+#include "NTLconvert.h"
+#endif
 
 //{{{ void chineseRemainder ( const CanonicalForm & x1, const CanonicalForm & q1, const CanonicalForm & x2, const CanonicalForm & q2, CanonicalForm & xnew, CanonicalForm & qnew )
@@ -199 +202 @@
         if ( c.inCoeffDomain())
         {
-          result += power( x, i.exp() ) * Farey_n(c,q);
+#ifdef HAVE_NTL
+          if (c.inZ() && isOn (SW_USE_NTL))
+          {
+            ZZ NTLc= convertFacCF2NTLZZ (c);
+            bool lessZero= (sign (NTLc) == -1);
+            if (lessZero)
+              negate (NTLc, NTLc);
+            ZZ NTLq= convertFacCF2NTLZZ (q);
+            ZZ bound;
+            SqrRoot (bound, NTLq/2);
+            ZZ NTLnum, NTLden;
+            if (ReconstructRational (NTLnum, NTLden, NTLc, NTLq, bound, bound))
+            {
+              if (lessZero)
+                negate (NTLnum, NTLnum);
+              CanonicalForm num= convertNTLZZX2CF (to_ZZX (NTLnum), Variable (1));
+              CanonicalForm den= convertNTLZZX2CF (to_ZZX (NTLden), Variable (1));
+              On (SW_RATIONAL);
+              result += power (x, i.exp())*(num/den);
+              Off (SW_RATIONAL);
+            }
+          }
+          else
+#endif
+            result += power( x, i.exp() ) * Farey_n(c,q);
         }
         else