Changeset 20357b in git

Timestamp:

May 7, 2015, 10:25:29 AM (9 years ago)

Author:

Stephan Oberfranz <oberfran@…>

Branches:

(u'spielwiese', '4a9821a93ffdc22a6696668bd4f6b8c9de3e6c5f')

Children:

a817084b5284694230319ae82cddc45954052311

Parents:

1b0fdfeed37de935efef12130903a54bf744d61c

Message:

fractal walk for arbitrary Groebner bases

File:

• Singular/walk.cc (modified) (7 diffs)

Singular/walk.cc

@@ -6723 +6723 @@
  * Perturb the start weight vector at the top level, i.e. nlev = 1     *
  ***********************************************************************/
-static ideal rec_fractal_call(ideal G, int nlev, intvec* ivtarget, int printout)
+static ideal rec_fractal_call(ideal G, int nlev, intvec* ivtarget,
+             int reduction, int printout)
 {
   Overflow_Error =  FALSE;
@@ -6731 +6732 @@
   ring new_ring, testring;
   //ring extoRing;
-  ideal Gomega, Gomega1, Gomega2, F, F1, Gresult, Gresult1, G1, Gt;
+  ideal Gomega, Gomega1, Gomega2, FF, F, F1, Gresult, Gresult1, G1, Gt;
   int nwalks = 0;
   intvec* Mwlp;
@@ -7070 +7071 @@
       idString(Gomega,"//** rec_fractal_call: Gomega");
     }
+
+    if(reduction == 0)
+    {
+      /* Check whether the intermediate weight vector lies in the interior of the cone.
+       * If so, only perform reductions. Otherwise apply Buchberger's algorithm. */
+      FF = middleOfCone(G,Gomega);
+      if( FF != NULL)
+      {
+        idDelete(&G);
+        G = idCopy(FF);
+        idDelete(&FF);
+        /* Compue next vector. */
+        goto NEXT_VECTOR_FRACTAL;
+      } 
+    }
+
 #ifndef  BUCHBERGER_ALG
     if(isNolVector(omega) == 0)
@@ -7108 +7125 @@
       rChangeCurrRing(oRing);
       Gomega1 = idrMoveR(Gomega1, oRing,currRing);
-      Gresult = rec_fractal_call(idCopy(Gomega1),nlev+1,omega,printout);
+      Gresult = rec_fractal_call(idCopy(Gomega1),nlev+1,omega,reduction,printout);
     }
     if(printout > 2)
@@ -7539 +7556 @@
     }
 
-
-//////////////////////////////////// hier neu!!
-
-
-   if(reduction == 0)
-    {
-      //PrintS("\n//** rec_r_fractal_call: test middle of cone!\n");
+    if(reduction == 0)
+    {
+      /* Check whether the intermediate weight vector lies in the interior of the cone.
+       * If so, only perform reductions. Otherwise apply Buchberger's algorithm. */
       FF = middleOfCone(G,Gomega);
-      //PrintS("\n//** rec_r_fractal_call: Test F!\n");
       if( FF != NULL)
       {
@@ -7553 +7566 @@
         G = idCopy(FF);
         idDelete(&FF);
-        PrintS("\n//** rec_r_fractal_call: FF nicht NULL! Compue next vector.\n");
+        /* Compue next vector. */
         goto NEXT_VECTOR_FRACTAL;
       } 
     }
-
-
-
-///////////////////////////////////////////////////
-
 
 #ifndef  BUCHBERGER_ALG
@@ -7779 +7787 @@
   ring helpRing = currRing;
 
-  J = rec_fractal_call(J,1,ivtarget,printout);
+  J = rec_fractal_call(J,1,ivtarget,reduction,printout);
 
   rChangeCurrRing(oldRing);