Changeset c95632f in git

Timestamp:

Jan 27, 2005, 5:41:12 PM (18 years ago)

Author:

Hans Schönemann <hannes@…>

Branches:

(u'jengelh-datetime', 'ceac47cbc86fe4a15902392bdbb9bd2ae0ea02c6')(u'spielwiese', '7725b5cfc1eaf99630826ecc59f559d3b6831c24')

Children:

cf5fc11febc65499165e79274d51a6d847e1391b

Parents:

a89a11590ebf9f1947d433a1980705a4cff8a5e3

Message:

*hannes: singclap_resultant: fix for denominator !=1


git-svn-id: file:///usr/local/Singular/svn/trunk@7693 2c84dea3-7e68-4137-9b89-c4e89433aadc

File:

• kernel/clapsing.cc (modified) (3 diffs)

kernel/clapsing.cc

@@ -3 +3 @@
 *  Computer Algebra System SINGULAR     *
 ****************************************/
-// $Id: clapsing.cc,v 1.3 2004-12-15 17:45:10 Singular Exp $
+// $Id: clapsing.cc,v 1.4 2005-01-27 16:41:12 Singular Exp $
 /*
 * ABSTRACT: interface between Singular and factory
@@ -275 +275 @@
 }
 
+/*2 find the maximal exponent of var(i) in poly p*/
+int pGetExp_Var(poly p, int i)
+{
+  int m=0;
+  int mm;
+  while (p!=NULL)
+  {
+    mm=pGetExp(p,i);
+    if (mm>m) m=mm;
+    pIter(p);
+  }
+  return m;
+}
+
 poly singclap_resultant ( poly f, poly g , poly x)
 {
@@ -315 +329 @@
     {
       Variable X(i+rPar(currRing));
+      number nf,ng;
+      pCleardenom_n(f,nf);pCleardenom_n(g,ng);
+      int ef,eg;
+      ef=pGetExp_Var(f,i);
+      eg=pGetExp_Var(g,i);
       CanonicalForm F( convSingTrPClapP( f ) ), G( convSingTrPClapP( g ) );
       res= convClapPSingTrP( resultant( F, G, X ) );
+      if ((nf!=NULL)&&(!nIsOne(nf))&&(!nIsZero(nf)))
+      {
+        number n=nInvers(nf);
+        while(eg>0)
+        {
+          res=pMult_nn(res,n);
+          eg--;
+        }
+        nDelete(&n);
+      }
+      nDelete(&nf);
+      if ((ng!=NULL)&&(!nIsOne(ng))&&(!nIsZero(ng)))
+      {
+        number n=nInvers(ng);
+        while(ef>0)
+        {
+          res=pMult_nn(res,n);
+          ef--;
+        }
+        nDelete(&n);
+      }
+      nDelete(&ng);
     }
     Off(SW_RATIONAL);