Changeset 6f30b8 in git

Timestamp:

Jun 22, 2011, 2:06:03 PM (12 years ago)

Author:

Martin Lee <martinlee84@…>

Branches:

(u'jengelh-datetime', 'ceac47cbc86fe4a15902392bdbb9bd2ae0ea02c6')(u'spielwiese', 'a800fe4b3e9d37a38c5a10cc0ae9dfa0c15a4ee6')

Children:

368602a55ed4fcad6d7f470cbbaa9e51c309b4ea

Parents:

64e7cb73f028e3866617e41d55fd0265168a395d

Message:

added computation of squarefree part


git-svn-id: file:///usr/local/Singular/svn/trunk@14297 2c84dea3-7e68-4137-9b89-c4e89433aadc

Location:

factory

Files:

• fac_sqrfree.cc (modified) (2 diffs)
• fac_sqrfree.h (modified) (1 diff)

factory/fac_sqrfree.cc

@@ -8 +8 @@
 #include "cf_defs.h"
 #include "canonicalform.h"
+#include "cf_map.h"
 
 static int divexp = 1;
@@ -180 +181 @@
     return F;
 }
+
+CanonicalForm 
+sqrfPart (const CanonicalForm& F)
+{
+  if (F.inCoeffDomain())
+    return F;
+  CFMap M;
+  CanonicalForm A= compress (F, M);
+  CanonicalForm w, v, b;
+  CanonicalForm result;
+  int i= 1;
+  for (; i <= A.level(); i++)
+  {
+    if (!deriv (A, Variable (i)).isZero())
+      break;
+  }
+
+  w= gcd (A, deriv (A, Variable (i)));
+  b= A/w;
+  result= b;
+  if (degree (w) < 1)
+    return M (result);
+  i++;
+  for (; i <= A.level(); i++)
+  {
+    if (!deriv (w, Variable (i)).isZero())
+    {
+      b= w;
+      w= gcd (w, deriv (w, Variable (i)));
+      b /= w;
+      if (degree (b) < 1)
+        break;
+      CanonicalForm g= gcd (b, result);
+      if (degree (g) > 0)
+        result *= b/g;
+      if (degree (g) <= 0)
+        result *= b;
+    }
+  }
+  result= M (result);
+  return result;
+}
+

factory/fac_sqrfree.h

@@ -19 +19 @@
 bool isSqrFreeZ ( const CanonicalForm & f );
 
+/// squarefree part of a poly
+CanonicalForm sqrfPart (const CanonicalForm& F ///<[in] some poly
+                       );
+
 #endif /* ! INCL_FAC_SQRFREE_H */