Changeset 5a4e17 in git for libpolys/polys/ext_fields/transext.cc

Timestamp:

Aug 14, 2013, 5:44:47 PM (10 years ago)

Author:

Hans Schoenemann <hannes@…>

Branches:

(u'spielwiese', '8e0ad00ce244dfd0756200662572aef8402f13d5')

Children:

e7af713b2118666efd56a51c8fd09dcc0b99e0ee

Parents:

adae8b2811aa80401958b914b4cfc7d0ad8eb36b

Message:

chg: improve ntNormalize etc.

File:

• libpolys/polys/ext_fields/transext.cc (modified) (4 diffs)

libpolys/polys/ext_fields/transext.cc

@@ -1100 +1100 @@
 
   fraction f = (fraction)a;
-  if (DENIS1(f) || NUMIS1(f)) { COM(f) = 0; ntTest(a); return; }
+  if (COM(f)!=0) p_Normalize(NUM(f), ntRing);
+  if (DENIS1(f) || NUMIS1(f)) { COM(f) = 0; return; }
+
+  p_Normalize(DEN(f), ntRing);
 
   assume( DEN(f) != NULL );
@@ -1153 +1156 @@
 
   if (IS0(a)) return;
-  if (NUM(f)!=NULL) p_Normalize(NUM(f), ntRing);
-  if (DEN(f)!=NULL) p_Normalize(DEN(f), ntRing);
   if (!simpleTestsHaveAlreadyBeenPerformed)
   {
+    p_Normalize(NUM(f), ntRing);
+    if (DEN(f)!=NULL) p_Normalize(DEN(f), ntRing);
     if (DENIS1(f) || NUMIS1(f)) { COM(f) = 0; return; }
 
@@ -1169 +1172 @@
     }
   }
+  if (rField_is_Q(ntRing))
+  {
+    number c=n_Copy(pGetCoeff(NUM(f)),ntCoeffs);
+    poly p=pNext(NUM(f));
+    while((p!=NULL)&&(!n_IsOne(c,ntCoeffs)))
+    {
+      number cc=n_Gcd(c,pGetCoeff(p),ntCoeffs);
+      n_Delete(&c,ntCoeffs);
+      c=cc;
+      pIter(p);
+    };
+    p=DEN(f);
+    while((p!=NULL)&&(!n_IsOne(c,ntCoeffs)))
+    {
+      number cc=n_Gcd(c,pGetCoeff(p),ntCoeffs);
+      n_Delete(&c,ntCoeffs);
+      c=cc;
+      pIter(p);
+    };
+    if(!n_IsOne(c,ntCoeffs))
+    {
+      p=NUM(f);
+      do
+      {
+        number cc=n_Div(pGetCoeff(p),c,ntCoeffs);
+        n_Normalize(cc,ntCoeffs);
+        p_SetCoeff(p,cc,ntRing);
+        pIter(p);
+      } while(p!=NULL);
+      p=DEN(f);
+      do
+      {
+        number cc=n_Div(pGetCoeff(p),c,ntCoeffs);
+        n_Normalize(cc,ntCoeffs);
+        p_SetCoeff(p,cc,ntRing);
+        pIter(p);
+      } while(p!=NULL);
+      n_Delete(&c,ntCoeffs);
+      if(pNext(DEN(f))==NULL)
+      {
+        if (p_IsOne(DEN(f),ntRing))
+        {
+          p_LmDelete(&DEN(f),ntRing);
+          COM(f)=0;
+          return;
+        }
+        else
+        {
+          return;
+        }
+      }
+    }
+  }
 
 #ifdef HAVE_FACTORY
-  /* Note that, over Q, singclap_gcd will remove the denominators in all
-     rational coefficients of pNum and pDen, before starting to compute
-     the gcd. Thus, we do not need to ensure that the coefficients of
-     pNum and pDen live in Z; they may well be elements of Q\Z. */
-  /* singclap_gcd destroys its arguments; we hence need copies: */
-  poly pGcd = singclap_gcd(p_Copy(NUM(f), ntRing), p_Copy(DEN(f), ntRing), cf->extRing);
-  if (p_IsConstant(pGcd, ntRing) &&
-      n_IsOne(p_GetCoeff(pGcd, ntRing), ntCoeffs))
+  poly pGcd;
+  /* here we assume: NUM(f), DEN(f) !=NULL, in Z_a reqp. Z/p_a */
+    pGcd = singclap_gcd_r(NUM(f), DEN(f), ntRing);
+  if (p_IsConstant(pGcd, ntRing)
+  //&& n_IsOne(p_GetCoeff(pGcd, ntRing), ntCoeffs)
+  )
   { /* gcd = 1; nothing to cancel;
        Suppose the given rational function field is over Q. Although the
@@ -1350 +1404 @@
      the gcd. Thus, we do not need to ensure that the coefficients of
      pa and pb live in Z; they may well be elements of Q\Z. */
-  poly pGcd = singclap_gcd(pa, pb, cf->extRing);
+  poly pGcd = singclap_gcd(pa, pb, ntRing);
   if (p_IsConstant(pGcd, ntRing) &&
       n_IsOne(p_GetCoeff(pGcd, ntRing), ntCoeffs))