Changeset cdec33 in git for kernel/longalg.cc

Timestamp:

Apr 7, 2011, 4:33:45 PM (12 years ago)

Author:

Frank Seelisch <seelisch@…>

Branches:

(u'spielwiese', '828514cf6e480e4bafc26df99217bf2a1ed1ef45')

Children:

c0b2e03243dcc8b84e3afb3a38cac55b6bb590c8

Parents:

73624c6eb72939321ed403d522f0f94a290bca1a

Message:

fix for ticket #329

git-svn-id: file:///usr/local/Singular/svn/trunk@14114 2c84dea3-7e68-4137-9b89-c4e89433aadc

File:

• kernel/longalg.cc (modified) (4 diffs)

kernel/longalg.cc

@@ -66 +66 @@
   n->nIsMOne        = naIsMOne;
   n->nGreaterZero   = naGreaterZero;
+  n->nGreater       = naGreater;
   n->cfWrite        = naWrite;
   n->nRead          = naRead;
@@ -99 +100 @@
   nIsMOne = naIsMOne;
   nGreaterZero = naGreaterZero;
+  nGreater = naGreater;
   nRead = naRead;
   nPower = naPower;
@@ -174 +176 @@
   nacIsZero      = nacRing->cf->nIsZero;
   nacGreaterZero = nacRing->cf->nGreaterZero;
+  nacGreater     = nacRing->cf->nGreater;
   nacIsOne       = nacRing->cf->nIsOne;
   nacGcd         = nacRing->cf->nGcd;
@@ -737 +740 @@
 
 
+/* This method will only consider the numerators of a and b.
+   Moreover it may return TRUE only if one or both numerators
+   are zero or if their degrees are equal. Then TRUE is returned iff
+   coeff(numerator(a)) > coeff(numerator(b));
+   In all other cases, FALSE will be returned. */
 BOOLEAN naGreater (number a, number b)
 {
-  if (naIsZero(a))
-    return FALSE;
-  if (naIsZero(b))
-    return TRUE; /* a!= 0)*/
-  return napDeg(((lnumber)a)->z)>napDeg(((lnumber)b)->z);
+  int az = 0; int ad = 0;
+  if (naIsZero(a)) az = 1;
+  else ad = napDeg(((lnumber)a)->z);
+  int bz = 0; int bd = 0;
+  if (naIsZero(b)) bz = 1;
+  else bd = napDeg(((lnumber)b)->z);
+  
+  if ((az == 1) && (bz == 1)) /* a = b = 0 */ return FALSE;
+  if (az == 1) /* a = 0, b != 0 */
+  {
+    return (!nacGreaterZero(pGetCoeff(((lnumber)b)->z)));
+  }
+  if (bz == 1) /* a != 0, b = 0 */
+  {
+    return (nacGreaterZero(pGetCoeff(((lnumber)a)->z)));
+  }
+  if (ad == bd)  
+    return nacGreater(pGetCoeff(((lnumber)a)->z),
+                      pGetCoeff(((lnumber)b)->z));
+  return FALSE;
 }