Changeset 8f57c0 in git for Singular

Timestamp:

May 7, 2012, 3:56:23 PM (12 years ago)

Author:

Oleksandr Motsak <motsak@…>

Branches:

(u'spielwiese', '4a9821a93ffdc22a6696668bd4f6b8c9de3e6c5f')

Children:

4b2e47d69832168747120de4721b9900101c96c7

Parents:

6b6c822fcfbbabb80e5ab1e0487f5de527e8785a

git-author:

Oleksandr Motsak <motsak@mathematik.uni-kl.de>2012-05-07 15:56:23+02:00

git-committer:

Oleksandr Motsak <motsak@mathematik.uni-kl.de>2012-05-10 18:23:39+02:00

Message:

further Schreyer Syzygy impl.

add: compute M_i
add: starting to traverse

File:

• Singular/LIB/schreyer.lib (modified) (2 diffs)

Singular/LIB/schreyer.lib

@@ -614 +614 @@
 }
 
+
+LIB "poly.lib"; // for lcm
+
+
+proc SSComputeLeadingSyzygyTerms(def L, int iCompShift)
+{
+  int @DEBUG = !system("with", "ndebug");
+
+  if( @DEBUG )
+  {
+    "SSComputeLeadingSyzygyTerms::Input: ";
+    L;
+    "iCompShift: ", iCompShift;
+
+  }
+
+  int i, j, r; intvec iv_ds;
+  int N = ncols(L);
+  def a, b;
+  poly aa, bb;
+
+  bigint c;
+
+  ideal M;
+
+  module S = 0;
+  
+  for(i = 1; i <= N; i++)
+  {
+    a = L[i];
+    "a: ", a;
+    c = leadcomp(a);
+    r = int(c);
+    aa = a[r];
+
+    M = 0;
+    
+    for(j = i-1; j > 0; j--)
+    {
+      b = L[j];
+      "b: ", b;
+
+      if( leadcomp(b) == c )
+      {
+        bb = b[r];
+
+        M[j] = (lcm(aa, bb) / aa);
+      }
+    }
+
+    M = simplify(M, 1 + 2 + 32);
+
+    iv_ds = sort(M, "ds", 1)[2]; // ,1 => reversed!
+
+    M = M[iv_ds];
+    
+    S = S, M * gen(i + iCompShift);
+  }
+
+  S = simplify(S, 2);
+
+  
+  if( @DEBUG )
+  {
+    "SSComputeLeadingSyzygyTerms::Output: ";
+    S;
+  }
+
+  return (S);
+
+}
+
+proc Traverse(mult, index, Leads, Tails, LSyz)
+{
+
+
+}
+
+
+
 // module (N, LL, TT) = SSComputeSyzygy(L, T, @RANK); // shift syz.comp by @RANK!
 proc SSComputeSyzygy(def M, def L, def T, int iCompShift)
@@ -639 +719 @@
   // !!!!!!!!!!!!!!!!!!!!!!!!!!!! TODO !!!!!!!!!!!!!!!!!!!!!!!!!!!! // 
   // !!!!!!!!!!!!!!!!!!!!!!!!!!!! TODO !!!!!!!!!!!!!!!!!!!!!!!!!!!! // 
-  // !!!!!!!!!!!!!!!!!!!!!!!!!!!! TODO !!!!!!!!!!!!!!!!!!!!!!!!!!!! // 
+  // !!!!!!!!!!!!!!!!!!!!!!!!!!!! TODO !!!!!!!!!!!!!!!!!!!!!!!!!!!! //
+
+  def a; bigint c; int r, k; poly aa;
+  
+  def LS = SSComputeLeadingSyzygyTerms(L, 0); // iCompShift // 0?
+  for(k = ncols(LS); k >= 0; k-- )
+  {
+    a = LS[k];
+    "A: ", a;
+    c = leadcomp(a);
+    r = int(c);
+    aa = a[r];
+
+    Traverse(aa, r, L, T, LS);
+  }