Changeset efd410 in git for factory/facAbsFact.h

Timestamp:

Apr 14, 2013, 5:39:13 PM (10 years ago)

Author:

Martin Lee <martinlee84@…>

Branches:

(u'spielwiese', '0d6b7fcd9813a1ca1ed4220cfa2b104b97a0a003')

Children:

17a7106fdd1564dd01cf087f4bccde563274952e

Parents:

b79b580d0846a3639786db7a3baa5fe8d310d405

git-author:

Martin Lee <martinlee84@web.de>2013-04-14 17:39:13+02:00

git-committer:

Martin Lee <martinlee84@web.de>2013-05-02 11:42:37+02:00

Message:

chg: top level abs factorization interface

File:

• factory/facAbsFact.h (modified) (1 diff)

factory/facAbsFact.h

@@ -15 +15 @@
 #define FAC_ABS_FACT_H
 
+#include "assert.h"
+
 #include "canonicalform.h"
+#include "cf_map.h"
+#include "cfNewtonPolygon.h"
+
+CFAFList absFactorizeMain (const CanonicalForm& F);
+
+static inline
+void normalize (CFAFList & L)
+{
+  for (CFAFListIterator i= L; i.hasItem(); i++)
+    i.getItem()= CFAFactor (i.getItem().factor()/Lc (i.getItem().factor()),
+                            i.getItem().minpoly(), i.getItem().exp());
+}
+
+static inline
+CFAFList uniAbsFactorize (const CanonicalForm& F)
+{
+  CFFList rationalFactors= factorize (F);
+  CFFListIterator i= rationalFactors;
+  i++;
+  CanonicalForm mipo;
+  CFAFList result;
+  for (; i.hasItem(); i++)
+  {
+    mipo= rootOf (i.getItem().factor());
+    result.append (CFAFactor (i.getItem().factor(), mipo, i.getItem().exp()));
+  }
+  result.insert (CFAFactor (rationalFactors.getFirst().factor(), 1, 1));
+  return result;
+}
 
 /*BEGINPUBLIC*/
 
-CFFList absFactorize (const CanonicalForm& F);
+CFAFList absFactorize (const CanonicalForm& G);
 
 /*ENDPUBLIC*/
 
+CFAFList absFactorize (const CanonicalForm& G)
+{
+  //TODO handle homogeneous input
+  ASSERT (getNumVars (F) == 2, "expected bivariate input");
+  ASSERT (getCharacteristic() == 0 && isOn (SW_RATIONAL), "expected poly over Q");
+
+  CFMap N;
+  CanonicalForm F= compress (G, N);
+  bool isRat= isOn (SW_RATIONAL);
+  if (isRat)
+  {
+    F *= bCommonDen (F);
+    Off (SW_RATIONAL);
+  }
+  F /= icontent (F);
+  if (isRat)
+    On (SW_RATIONAL);
+
+  CanonicalForm contentX= content (F, 1);
+  CanonicalForm contentY= content (F, 2);
+  F /= (contentX*contentY);
+  CFAFList contentXFactors, contentYFactors;
+  contentXFactors= uniAbsFactorize (contentX);
+  contentYFactors= uniAbsFactorize (contentY);
+
+  if (contentXFactors.getFirst().factor().inCoeffDomain())
+    contentXFactors.removeFirst();
+  if (contentYFactors.getFirst().factor().inCoeffDomain())
+    contentYFactors.removeFirst();
+  if (F.inCoeffDomain())
+  {
+    CFAFList result;
+    for (CFAFListIterator i= contentXFactors; i.hasItem(); i++)
+      result.append (CFAFactor (N (i.getItem().factor()), i.getItem().minpoly(),
+                                i.getItem().exp()));
+    for (CFAFListIterator i= contentYFactors; i.hasItem(); i++)
+      result.append (CFAFactor (N (i.getItem().factor()),i.getItem().minpoly(),
+                                i.getItem().exp()));
+    normalize (result);
+    result.insert (CFAFactor (Lc (G), 1, 1));
+    return result;
+  }
+  CFFList rationalFactors= factorize (F);
+
+  CFAFList result, resultBuf;
+
+  CFAFListIterator iter;
+  CFFListIterator i= rationalFactors;
+  i++;
+  for (; i.hasItem(); i++)
+  {
+    resultBuf= absFactorizeMain (i.getItem().factor());
+    for (iter= resultBuf; iter.hasItem(); iter++)
+      iter.getItem()= CFAFactor (iter.getItem().factor(),
+                                 iter.getItem().minpoly(), i.getItem().exp());
+    result= Union (result, resultBuf);
+  }
+
+
+  for (CFAFListIterator i= result; i.hasItem(); i++)
+    i.getItem()= CFAFactor (N (i.getItem().factor()), i.getItem().minpoly(),
+                            i.getItem().exp());
+  for (CFAFListIterator i= contentXFactors; i.hasItem(); i++)
+    result.append (CFAFactor (N(i.getItem().factor()), i.getItem().minpoly(),
+                              i.getItem().exp()));
+  for (CFAFListIterator i= contentYFactors; i.hasItem(); i++)
+    result.append (CFAFactor (N(i.getItem().factor()), i.getItem().minpoly(),
+                              i.getItem().exp()));
+  normalize (result);
+  result.insert (CFAFactor (Lc(G), 1, 1));
+  return result;
+}
+
 #endif