Changeset 1a4c80b in git

Timestamp:

Jul 11, 2014, 12:30:51 PM (9 years ago)

Author:

Martin Lee <martinlee84@…>

Branches:

(u'spielwiese', '8e0ad00ce244dfd0756200662572aef8402f13d5')

Children:

4e2cc188f9d61d04296ddb7df63d0eaccd719584

Parents:

3169ca78b60cbcbd96901fbd89cf164a5ed0b62d

git-author:

Martin Lee <martinlee84@web.de>2014-07-11 12:30:51+02:00

git-committer:

Martin Lee <martinlee84@web.de>2014-07-17 12:07:11+02:00

Message:

chg: added leftShift of CanonicalForms
chg: use leftShift in computation of cyclotomic polys

Location:

factory

Files:

• canonicalform.h (modified) (1 diff)
• cf_cyclo.cc (modified) (1 diff)
• cf_ops.cc (modified) (1 diff)

factory/canonicalform.h

@@ -271 +271 @@
 
 bool hasFirstAlgVar( const CanonicalForm & f, Variable & a);
+
+CanonicalForm leftShift (const CanonicalForm& F, int n);
 //}}}
 

factory/cf_cyclo.cc

@@ -131 +131 @@
   for (int i= 0; i < distinct_factors_length; i++)
   {
-    result= result (power (x, distinct_factors[i]), x)/result;
+    result= leftShift (result, distinct_factors[i])/result;
     prod *= distinct_factors[i];
   }
-  return result (power (x, n/prod), x);
+  return leftShift (result, n/prod);
 }
 

factory/cf_ops.cc

@@ -677 +677 @@
   return false;
 }
+
+/** left shift the main variable of F by n
+ *  @return if x is the main variable of F the result is F(x^n)
+ **/
+CanonicalForm leftShift (const CanonicalForm& F, int n)
+{
+  ASSERT (n >= 0, "cannot left shift by negative number");
+  if (F.inBaseDomain())
+    return F;
+  if (n == 0)
+    return F;
+  Variable x=F.mvar();
+  CanonicalForm result= 0;
+  for (CFIterator i= F; i.hasTerms(); i++)
+    result += i.coeff()*power (x, i.exp()*n);
+  return result;
+}