Changeset e20214 in git for Singular/maps.cc

Timestamp:

Jul 13, 1999, 5:06:52 PM (24 years ago)

Author:

Hans Schönemann <hannes@…>

Branches:

(u'spielwiese', '8e0ad00ce244dfd0756200662572aef8402f13d5')

Children:

2eeb7d1017a21755a73976d7e957ee1db6cc06b2

Parents:

0a5f342e03dda534e299aecb4e831f39b5569cd7

Message:

*hannes: maEval optimized


git-svn-id: file:///usr/local/Singular/svn/trunk@3265 2c84dea3-7e68-4137-9b89-c4e89433aadc

File:

• Singular/maps.cc (modified) (4 diffs)

Singular/maps.cc

@@ -2 +2 @@
 *  Computer Algebra System SINGULAR     *
 ****************************************/
-/* $Id: maps.cc,v 1.14 1999-03-09 12:28:49 obachman Exp $ */
+/* $Id: maps.cc,v 1.15 1999-07-13 15:06:52 Singular Exp $ */
 /*
 * ABSTRACT - the mapping of polynomials to other rings
@@ -22 +22 @@
 #include "maps.h"
 
-#define MAX_MAP_DEG 32
+#define MAX_MAP_DEG 128
 
 /*2
@@ -37 +37 @@
 }
 
+
+/*2
+* return the image of var(v)^pExp, where var(v) maps to p
+*/
+poly maEvalVariable(poly p, int v,int pExp,matrix s)
+{
+  if (pExp==1)
+    return pCopy(p);
+
+  poly res;
+
+  if((s!=NULL)&&(pExp<MAX_MAP_DEG))
+  {
+    int j=2;
+    poly p0=p;
+    // find starting point
+    if(MATELEM(s,v,1)==NULL)
+    {
+      MATELEM(s,v,1)=pCopy(p/*theMap->m[v-1]*/);
+    }
+    else
+    {
+      while((j<=pExp)&&(MATELEM(s,v,j)!=NULL))
+      {
+        j++;
+      }
+      p0=MATELEM(s,v,j-1);
+    }
+    // multiply
+    for(;j<=pExp;j++)
+    {
+      p0=MATELEM(s,v,j)=pMult(pCopy(p0/*MATELEM(s,v,j-1)*/),
+                              pCopy(p/*theMap->m[v-1]*/));
+    }
+    res=pCopy(p0/*MATELEM(s,v,pExp)*/);
+  }
+  else //if ((p->next!=NULL)&&(p->next->next==NULL))
+  {
+    res=pPower(pCopy(p),pExp);
+  }
+  return res;
+}
+
+poly maEvalMonom(map theMap, poly p,ring preimage_r,matrix s)
+{
+    poly q=pOne();
+    pSetCoeff(q,nMap(pGetCoeff(p)));
+
+    int i;
+    for(i=preimage_r->N; i>0; i--)
+    {
+      int pExp=pRingGetExp(preimage_r, p,i);
+      if (pExp != 0)
+      {
+        if (theMap->m[i-1]!=NULL)
+        {
+          poly p1=theMap->m[i-1];
+          poly pp=maEvalVariable(p1,i,pExp,s);
+          q = pMult(q,pp);
+        }
+        else
+        {
+          pDelete(&q);
+          break;
+        }
+      }
+    }
+    int modulComp = pRingGetComp(preimage_r, p);
+    if (q!=NULL) pSetCompP(q,modulComp);
+  return q;
+}
+
 poly maEval(map theMap, poly p,ring preimage_r,matrix s)
 {
-  poly result = NULL,q,pp;
-  int i,modulComp;
-  int varnum = preimage_r->N;
-
-//  for(i=1; i<=varnum; i++)
+  poly result = NULL;
+  int i;
+
+//  for(i=1; i<=preimage_r->N; i++)
 //  {
 //    pTest(theMap->m[i-1]);
 //  }
-  while (p!=NULL)
-  {
-    q=pOne();
-    pSetCoeff(q,nMap(pGetCoeff(p)));
-
-    for(i=1; i<=varnum; i++)
-    {
-      int pExp=pRingGetExp(preimage_r, p,i);
-      if (pExp != 0)
-      {
-        if (theMap->m[i-1]!=NULL)
-        {
-          poly p1=theMap->m[i-1];
-          if((s!=NULL)&&(pExp<(MAX_MAP_DEG*2)))
-          {
-            int e=min(pExp,MAX_MAP_DEG);
-            if(MATELEM(s,i,e)!=NULL)
-              pp=pCopy(MATELEM(s,i,e));
-            else
-            {
-              int j=2;
-              poly p0=p1;
-              if(MATELEM(s,i,1)==NULL)
-              {
-                MATELEM(s,i,1)=pCopy(p1/*theMap->m[i-1]*/);
-              }
-              else
-              {
-                while((j<=e)&&(MATELEM(s,i,j)!=NULL))
-                {
-                  j++;
-                }
-                p0=MATELEM(s,i,j-1);
-              }
-              for(;j<=e;j++)
-              {
-                p0=MATELEM(s,i,j)=pMult(pCopy(p0/*MATELEM(s,i,j-1)*/),
-                                        pCopy(p1/*theMap->m[i-1]*/));
-              }
-              pp=pCopy(p0/*MATELEM(s,i,e)*/);
-            }
-            while(e!=pExp/*pRingGetExp(preimage_r, p,i)*/)
-            {
-              // e is the current exponent,
-              // MAX_MAP_DEG the max exponent in the table
-              // pExp the end exponent
-              pp=pMult(pp,pCopy(MATELEM(s,i,min(MAX_MAP_DEG,pExp-e))));
-              e+=min(MAX_MAP_DEG,pExp-e);
-            }
-          }
-          else
-          {
-            pp = pPower(pCopy(p1/*theMap->m[i-1]*/),pExp/*pRingGetExp(preimage_r, p,i)*/);
-          }
-          q = pMult(q,pp);
-        }
-        else
-        {
-          pDelete(&q);
-          break;
-        }
-      }
-    }
-    modulComp = pRingGetComp(preimage_r, p);
-    if (q!=NULL) pSetCompP(q,modulComp);
-    result = pAdd(result,q);
-    pIter(p);
-  }
-  if (currRing->minpoly!=NULL) result=pMult(result,pOne());
+//  while (p!=NULL)
+//  {
+//    poly q=maEvalMonom(theMap,p,preimage_r,s);
+//    result = pAdd(result,q);
+//    pIter(p);
+//  }
+  if (p!=NULL)
+  {
+    int l = pLength(p)-1;
+    poly* monoms;
+    if (l>0)
+    {
+      monoms = (poly*) Alloc(l*sizeof(poly));
+
+      for (i=0; i<l; i++)
+      {
+        monoms[i]=maEvalMonom(theMap,p,preimage_r,s);
+        pIter(p);
+      }
+    }
+    result=maEvalMonom(theMap,p,preimage_r,s);
+    if (l>0)
+    {
+      for(i = l-1; i>=0; i--)
+      {
+        result=pAdd(result, monoms[i]);
+      }
+      Free((ADDRESS)monoms,l*sizeof(poly));
+    }
+    if (currRing->minpoly!=NULL) result=pMult(result,pOne());
+  }
   pTest(result);
   return result;
@@ -280 +313 @@
 
 void maFindPerm(char **preim_names, int preim_n, char **preim_par, int preim_p,
-                char **names,       int n,       char **par,       int nop, 
+                char **names,       int n,       char **par,       int nop,
                 int * perm, int *par_perm, int ch)
 {