Changeset 637aa3 in git for Singular

Timestamp:

Sep 21, 2016, 8:50:47 PM (8 years ago)

Author:

Sharwan Tiwari <stiwari@…>

Branches:

(u'spielwiese', 'fe61d9c35bf7c61f2b6cbf1b56e25e2f08d536cc')

Children:

340ab86324a89fa970583967bc2dc82e455bac1d

Parents:

579edfd1e445a134cdaeced2df1b8db73d9b7d9b

git-author:

Sharwan Tiwari <stiwari@gmail.com>2016-09-21 20:50:47+02:00

git-committer:

Sharwan Tiwari <stiwari@gmail.com>2016-10-11 17:40:28+02:00

Message:

modified nchilb

Location:

Singular

Files:

• LIB/ncHilb.lib (modified) (6 diffs)
• extra.cc (modified) (1 diff)

Singular/LIB/ncHilb.lib

@@ -14 +14 @@
 
 PROCEDURES:
-          nchilb(L, d, #); gives the Hilbert series of a monomial algebra
-          (free algebra/two-sided monomial ideal). 
-          List L contains non-comm. polynomials.
-          And d is a degree bound for the Groebner basis computation of 
-          the ideal generated by L. Third argument is optional, required for
-          the non-finitely generated ideals.
+          nchilb(L, d, #); Hilbert series of a non-commutative monomial algebra
+
 ";
 
@@ -39 +35 @@
 EXAMPLE: example nchilb; shows an example "
 {
-    system("--ticks-per-sec",1000); 
-    if (d<1) {"bad degree bound"; return(0);}
-    printlevel=1; 
+
+    if (d<1) 
+    {
+      ERROR("bad degree bound");
+    }
+    
     def save = basering;
     int sz=size(#);
@@ -49 +48 @@
     setring R;
     ideal I;
-    poly p=0;
-    
+    poly p;
+    poly q=0;
     // convert list L_wp of free-poly to letterPlace-poly format 
     setring save;
     module M;
     int i,j,k,sw,sm,slm;
-    vector w;                            // for words 
-    slm = size(L_wp);                    // number of polys in the given ideal
-    string letpl;
+    vector w;
+    poly pc=0;
+    intvec v; 
+    slm = size(L_wp);                  // number of polys in the given ideal
+    
     for (i=1; i<=slm; i++)
-    {
+    {   
         M  = L_wp[i];
-        sm = ncols(M);                   // number of words in the free-poly M
+        sm = ncols(M);                 // number of words in the free-poly M
         for (j=1; j<=sm; j++)
         {
             w  = M[j];
             sw = size(w); 
-            letpl = "p = p + ";
             for (k=2; k<=sw; k++)
             {
-                letpl = letpl + string(w[k])+"("+string(k-1)+")*";
+              v[k-1]=rvar(w[k]);
             }
-            letpl = letpl + string(w[1])+";";
-            
+            pc=w[1];
             setring R;
-            execute(letpl);
+            p=imap(save,pc);
+            for (k=2; k<=sw; k++)
+            {
+              p=p*var(v[k-1]+(k-2)*lV);
+            }
+            q=q+p;
             setring save;
         }
         setring R;
-        I = I,p; //lp-polynomial added to I
-        p = 0;   //ready for the next polynomial  
+        I = I,q; //lp-polynomial added to I
+        q=0;   //ready for the next polynomial  
         setring save;
     }
-    kill letpl;
     setring R;
-    int tt,rt;
-    
-    tt=timer;
-    rt=rtimer;
+
     ideal J = system("freegb",I,d,lV);
     
-    if(printlevel >=2)
-    {
-         "CPU-time of GB computation="+string(timer-tt)+" milli-sec.";
-         "Real-time of GB computation="+string(rtimer-rt)+" milli-sec.";
-    }
-    
     //Groebner Basis is computed for the given ideal.
-    //now compute the leading monomials of Groebner Basis
+    //now compute the leading monomials of the Groebner Basis
     
     ideal J_lm;
@@ -111 +105 @@
     
     //compute the Hilbert series
-    tt=timer;
-    rt=rtimer;
-    if(sz==1)
+    
+    if(sz==1)                     // non-finitely generated case
     {
         system("nc_hilb",I,lV,1);
     }
-    else
+    else                         // finitely generated case
     {
         system("nc_hilb",I,lV);
     }
-    if(printlevel >=2)
-    {
-        "CPU-time of Hilbert series computation="+string(timer-tt)+" milli-sec.";
-        "Real-time of Hilbert series computation="+string(rtimer-rt)+" milli-sec.";  
-    }
-
 }
 example
@@ -132 +119 @@
 "EXAMPLE:"; echo = 2;
     ring r=0,(x,y,z),dp;
-    module p1=[1,y,z],[-1,z,y];      // represents the poly y*z-z*y
-    module p2=[1,x,z,x],[-1,z,x,z]; //represents the poly x*z*x-z*x*z
+    module p1=[1,y,z],[-1,z,y];           //represents the poly y*z-z*y
+    module p2=[1,x,z,x],[-1,z,x,z];    //represents the poly x*z*x-z*x*z
     list l1=list(p1,p2);
     nchilb(l1,6,1); //third argument is for non-finitely generated case
     
     ring r=0,(x,y,z,w),dp;
-    module p1=[1,y,x],[-1,x,y];
+    module p1=[1,y,x],[-1,x,y];            //represents the poly y*x-x*y
     module p2=[1,z,x],[-1,x,z];
     module p3=[1,w,x],[-1,x,w];
@@ -148 +135 @@
         
     ring r=0,(X,Y,Z),dp;
-    module p1 =[1,Y,Z];
+    module p1 =[1,Y,Z];                //represents the poly Y*Z
     module p2 =[1,Y,Z,X];
     module p3 =[1,Y,Z,Z,X,Z];

Singular/extra.cc

@@ -3046 +3046 @@
       else
   #endif
-        //==========================================================
-        // Hilbert series for non-comm. monomial algebras
-        // =========================================================
-  if(strcmp(sys_cmd,"nc_hilb")==0)
-        {
-                ideal i;
-    int lV;
-                bool ig=FALSE;
-                if((h!=NULL)&&(h->Typ()==IDEAL_CMD))
-                        i=(ideal)h->Data();
-                        else return TRUE;
-                        h=h->next;
-      if((h!=NULL)&&(h->Typ()==INT_CMD))
-        lV=(int)(long)h->Data();
-      else return TRUE;
-      h=h->next;
-                        if(h!=NULL)
-                        ig=TRUE;
-                        HilbertSeries_OrbitData(i,lV,ig);
-                        return(FALSE);
-    }
-                else
-
-        /*==================== sca?AltVar ==================================*/
+    /*======================================================
+     * Hilbert series of non-commutative monomial algebras
+     *======================================================*/
+      if(strcmp(sys_cmd,"nc_hilb") == 0)
+      {
+        ideal i;
+        int lV;
+        bool ig = FALSE;
+        if((h != NULL)&&(h->Typ() == IDEAL_CMD))
+          i = (ideal)h->Data();
+        else
+        {
+          WerrorS("ideal expected");
+          return TRUE;
+        }
+        h = h->next;
+        if((h != NULL)&&(h->Typ() == INT_CMD))
+          lV = (int)(long)h->Data();
+        else 
+        { 
+          WerrorS("int expected"); 
+          return TRUE;
+        }
+        h = h->next;
+        if(h != NULL)
+          ig = TRUE;
+        HilbertSeries_OrbitData(i,lV,ig);
+        return(FALSE);
+      }
+      else
+
+    /*==================== sca?AltVar ==================================*/
   #ifdef HAVE_PLURAL
       if ( (strcmp(sys_cmd, "AltVarStart") == 0) || (strcmp(sys_cmd, "AltVarEnd") == 0) )