Changeset 39d731 in git

Timestamp:

Aug 10, 2012, 5:52:11 PM (11 years ago)

Author:

Hans Schoenemann <hannes@…>

Branches:

(u'spielwiese', '8e0ad00ce244dfd0756200662572aef8402f13d5')

Children:

285a39387fec8e81c98db529fa68b87b73a65cd6

Parents:

73260639099e75033ef78f48ad34a0ee10e1c15e

Message:

fix: nlClearDenom/nlContent: lead coeff >0

File:

• libpolys/coeffs/longrat.cc (modified) (4 diffs)

libpolys/coeffs/longrat.cc

@@ -2653 +2653 @@
   s=2147483647; // max. int
   numberCollectionEnumerator.Reset();
+  int lc_is_pos=nlGreaterZero(numberCollectionEnumerator.Current(),cf);
   do
   {
     cand1= numberCollectionEnumerator.Current();
     if (SR_HDL(cand1)&SR_INT) { cand=cand1;break;}
+    assume(cand1->s==3); // all coeffs should be integers
     s1=mpz_size1(cand1->z);
     if (s>s1)
@@ -2671 +2673 @@
   {
     nlNormalize(numberCollectionEnumerator.Current(),cf);
-    cand1= nlGcd(cand,numberCollectionEnumerator.Current(),cf);
-    nlDelete(&cand,cf);
+    nlInpGcd(cand,numberCollectionEnumerator.Current(),cf);
     cand=cand1;
-    if(nlIsOne(cand,cf)) { c=cand; return; }
+    if(nlIsOne(cand,cf))
+    {
+      c=cand;
+      if(!lc_is_pos)
+      {
+        // make the leading coeff positive
+        c=nlNeg(c,cf);
+        numberCollectionEnumerator.Reset();
+        do
+        {
+          numberCollectionEnumerator.Current()=nlNeg(numberCollectionEnumerator.Current(),cf);
+        } while (numberCollectionEnumerator.MoveNext() );
+      }
+      return;
+    }
   } while (numberCollectionEnumerator.MoveNext() );
 
   // part3: all coeffs = all coeffs / cand
+  if (!lc_is_pos) cand=nlNeg(cand,cf);
   c=cand;
   numberCollectionEnumerator.Reset();
@@ -2707 +2723 @@
   mpz_init(tmp);
   numberCollectionEnumerator.Reset();
+  int lc_is_pos=nlGreaterZero(numberCollectionEnumerator.Current(),cf);
   do
   {
@@ -2739 +2756 @@
     mpz_clear(tmp);
     FREE_RNUMBER(cand);
-    c=nlInit(1,cf);
+    if (lc_is_pos)
+      c=nlInit(1,cf);
+    else
+    {
+      // make the leading coeff positive
+      c=nlInit(-1,cf);
+      numberCollectionEnumerator.Reset();
+      do
+      {
+        numberCollectionEnumerator.Current()=nlNeg(numberCollectionEnumerator.Current(),cf);
+      } while (numberCollectionEnumerator.MoveNext() );
+    }
     return;
   }