NEW: scalingPolytope, overloaded '*'

scalingPolytope scales a polytope by an integer factor, can be used through overloaded '*' if polymake is loaded.
Singular · Feb 24, 2012 · 0e07c1f · 0e07c1f
1 parent ba53ff2
commit 0e07c1f
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Showing 2 changed files with 51 additions and 6 deletions.
diff --git a/callgfanlib/bbpolytope.cc b/callgfanlib/bbpolytope.cc
@@ -493,6 +493,33 @@ BOOLEAN newtonPolytope(leftv res, leftv args)
   return TRUE;
 }
 
+BOOLEAN scalePolytope(leftv res, leftv args)
+{
+  leftv u = args;
+  if ((u != NULL) && (u->Typ() == INT_CMD))
+  {
+    leftv v = u->next;
+    if ((v != NULL) && (v->Typ() == polytopeID))
+    {
+
+      int* n = (int*) u->Data();
+      gfan::ZCone* zp = (gfan::ZCone*) v->Data();
+      gfan::ZMatrix zm = zp->extremeRays();
+      for (int i=1; i<zm.getHeight(); i++)
+        for (int j=1; j<zm.getWidth(); j++)
+          zm[i][j]+=1;
+      gfan::ZCone* zq = new gfan::ZCone();
+      *zq = gfan::ZCone::givenByRays(zm,gfan::ZMatrix(0, zm.getWidth()));
+      res->rtyp = polytopeID;
+      res->data = (char*) zq;
+      return FALSE;
+    }
+  }
+  WerrorS("scalePolytope: unexpected parameters");
+  return TRUE;
+
+}
+
 void bbpolytope_setup()
 {
   blackbox *b=(blackbox*)omAlloc0(sizeof(blackbox));
@@ -511,6 +538,7 @@ void bbpolytope_setup()
   iiAddCproc("","quickPolytopeViaNormals",FALSE,quickPolytopeViaNormals);
   iiAddCproc("","getVertices",FALSE,getVertices);
   iiAddCproc("","newtonPolytope",FALSE,newtonPolytope);
+  iiAddCproc("","scalePolytope",FALSE,scalePolytope);
   /********************************************************/
   /* the following functions are implemented in bbcone.cc */
   // iiAddCproc("","getAmbientDimension",FALSE,getAmbientDimension);                                               

diff --git a/callpolymake/polymake.cc b/callpolymake/polymake.cc
@@ -317,16 +317,16 @@ polymake::perl::Object ZFan2PmFan (gfan::ZFan* zf)
 /*******************************************************/
 
 
-static BOOLEAN bbpolytope_Op2(int op, leftv res, leftv p, leftv q)
+static BOOLEAN bbpolytope_Op2(int op, leftv res, leftv i1, leftv i2)
 {
-  gfan::ZCone* zp = (gfan::ZCone*) p->Data();
+  gfan::ZCone* zp = (gfan::ZCone*) i1->Data();
   switch(op)
   {
     case '+':
     {
-      if (q->Typ()==polytopeID)
+      if (i2->Typ()==polytopeID)
       {
-        gfan::ZCone* zq = (gfan::ZCone*) q->Data();
+        gfan::ZCone* zq = (gfan::ZCone*) i2->Data();
         gfan::ZCone* ms;
         try
         {
@@ -347,10 +347,27 @@ static BOOLEAN bbpolytope_Op2(int op, leftv res, leftv p, leftv q)
       }
       return TRUE;
     }
+    case '*':
+    {
+      if (i2->Typ()==INT_CMD)
+      {
+        int* s = (int*) i2->Data();
+        gfan::ZMatrix zm = zp->extremeRays();
+        for (int i=1; i<zm.getHeight(); i++)
+          for (int j=1; j<zm.getWidth(); j++)
+            zm[i][j]+=1;
+        gfan::ZCone* zs = new gfan::ZCone();
+        *zs = gfan::ZCone::givenByRays(zm,gfan::ZMatrix(0, zm.getWidth()));
+        res->rtyp = polytopeID;
+        res->data = (void*) zs;
+        return FALSE;
+      }
+      return TRUE;
+    }
     default:
-      return blackboxDefaultOp2(op,res,p,q);
+      return blackboxDefaultOp2(op,res,i1,i2);
   }
-  return blackboxDefaultOp2(op,res,p,q);
+  return blackboxDefaultOp2(op,res,i1,i2);
 }