Changeset 311d099 in git

Timestamp:

Feb 1, 2021, 2:11:17 PM (2 years ago)

Author:

Hans Schoenemann <hannes@…>

Branches:

(u'jengelh-datetime', 'ceac47cbc86fe4a15902392bdbb9bd2ae0ea02c6')(u'spielwiese', 'a657104b677b4c461d018cbf3204d72d34ad66a9')

Children:

fc73643642b01f9111d972d15b22bae89ec11d36

Parents:

4218c13e2434358d0a056b78d0a40377a11bcdb1

Message:

rework jjSetMinpoly

Location:

Singular

Files:

• ipassign.cc (modified) (5 diffs)
• ipshell.h (modified) (1 diff)

Singular/ipassign.cc

@@ -171 +171 @@
   }
 }
-ring jjSetMinpoly(ring r, number a)
-{
-  if ( !nCoeff_is_transExt(r->cf) )
-  {
-    if(!nCoeff_is_algExt(r->cf) )
+// change the coeff cf=K[x] (of type n_transExt) to K[x]/a
+// return NULL in error case
+coeffs jjSetMinpoly(coeffs cf, number a)
+{
+  if ( !nCoeff_is_transExt(cf) )
+  {
+    if(!nCoeff_is_algExt(cf) )
     {
       WerrorS("cannot set minpoly for these coeffients");
@@ -181 +183 @@
     }
   }
-  if (rVar(r->cf->extRing)!=1)
-  {
-    WerrorS("only univarite minpoly allowed");
+  if (rVar(cf->extRing)!=1)
+  {
+    WerrorS("only univariate minpoly allowed");
     return NULL;
   }
 
-  assume (r->idroot==NULL);
-
-  number p = n_Copy(a,r->cf);
-  n_Normalize(p, r->cf);
-
-  if (n_IsZero(p, r->cf))
-  {
-    n_Delete(&p, r->cf);
-    if( nCoeff_is_transExt(r->cf) )
-    {
-      return r;
-    }
-    WarnS("cannot set minpoly to 0 / alg. extension?");
-    return NULL;
-  }
-  r=rCopy(r);
-  // remove all object currently in the ring
+  number p = n_Copy(a,cf);
+  n_Normalize(p, cf);
+
+  if (n_IsZero(p, cf))
+  {
+    n_Delete(&p, cf);
+    return cf;
+  }
 
   AlgExtInfo A;
 
-  A.r = rCopy(r->cf->extRing); // Copy  ground field!
+  A.r = rCopy(cf->extRing); // Copy  ground field!
   // if minpoly was already set:
-  if( r->cf->extRing->qideal != NULL ) id_Delete(&(A.r->qideal),A.r);
+  if( cf->extRing->qideal != NULL ) id_Delete(&(A.r->qideal),A.r);
   ideal q = idInit(1,1);
   if ((p==NULL) ||(NUM((fraction)p)==NULL))
@@ -216 +209 @@
     // cleanup A: TODO
     rDelete( A.r );
-    rDelete(r);
     return NULL;
   }
@@ -222 +214 @@
   {
     poly n=DEN((fraction)(p));
-    if(!p_IsConstant(n,r->cf->extRing))
+    if(!p_IsConstant(n,cf->extRing))
     {
       WarnS("denominator must be constant - ignoring it");
     }
-    p_Delete(&n,r->cf->extRing);
+    p_Delete(&n,cf->extRing);
     DEN((fraction)(p))=NULL;
   }
@@ -240 +232 @@
   if (new_cf==NULL)
   {
-    WerrorS("Could not construct the alg. extension: llegal minpoly?");
+    WerrorS("Could not construct the alg. extension: illegal minpoly?");
     // cleanup A: TODO
     rDelete( A.r );
-    rDelete(r);
     return NULL;
   }
-  else
-  {
-    nKillChar(r->cf); r->cf=new_cf;
-  }
-  return r;
+  return new_cf;
 }
 

Singular/ipshell.h

@@ -171 +171 @@
 /* Assigments : */
 BOOLEAN iiAssign(leftv left, leftv right, BOOLEAN toplevel=TRUE);
-ring jjSetMinpoly(ring r, number a);
+coeffs jjSetMinpoly(coeffs cf, number a);
 
 typedef BOOLEAN (*proci)(leftv,leftv,Subexpr);