Changeset 276c3f in git for factory/cf_ops.cc

Timestamp:

Jul 5, 2011, 3:16:22 PM (12 years ago)

Author:

Martin Lee <martinlee84@…>

Branches:

(u'jengelh-datetime', 'ceac47cbc86fe4a15902392bdbb9bd2ae0ea02c6')(u'spielwiese', '0604212ebb110535022efecad887940825b97c3f')

Children:

e28e6d1742e673c091f48a99b5d6d522e5d5bfa2

Parents:

faf58fa448fff6919168c75277259dc4202064b0

Message:

moved 'reduce' from algext.* to cf_ops.cc and canonicalform.h


git-svn-id: file:///usr/local/Singular/svn/trunk@14325 2c84dea3-7e68-4137-9b89-c4e89433aadc

File:

• factory/cf_ops.cc (modified) (1 diff)

factory/cf_ops.cc

@@ -659 +659 @@
 }
 //}}}
+
+CanonicalForm reduce(const CanonicalForm & f, const CanonicalForm & M)
+{ // polynomials in M.mvar() are considered coefficients
+  // M univariate monic polynomial
+  // the coefficients of f are reduced modulo M
+  if(f.inBaseDomain() || f.level() < M.level())
+    return f;
+  if(f.level() == M.level())
+  {
+    if(f.degree() < M.degree())
+      return f;
+    CanonicalForm tmp = mod (f, M);
+    return tmp;
+  }
+  // here: f.level() > M.level()
+  CanonicalForm result = 0;
+  for(CFIterator i=f; i.hasTerms(); i++)
+    result += reduce(i.coeff(),M) * power(f.mvar(),i.exp());
+  return result;
+}