Changeset 488808e in git

Timestamp:

May 26, 2011, 12:12:01 PM (12 years ago)

Author:

Frank Seelisch <seelisch@…>

Branches:

(u'jengelh-datetime', 'ceac47cbc86fe4a15902392bdbb9bd2ae0ea02c6')(u'spielwiese', '0604212ebb110535022efecad887940825b97c3f')

Children:

5a4b26f3e00776270c3ba83b16c92a69f3cca0e0

Parents:

73a9ffb72679635d0a4389f31022ac7b37564499

git-author:

Frank Seelisch <seelisch@mathematik.uni-kl.de>2011-05-26 12:12:01+02:00

git-committer:

Mohamed Barakat <mohamed.barakat@rwth-aachen.de>2011-11-09 12:36:53+01:00

Message:

removed calls to nCoeff_is_Q_a and nCoeff_is_Zp_a (kept definitions for compatibility towards svn trunk); changed map in algext.cc

Location:

libpolys

Files:

• coeffs/coeffs.h (modified) (10 diffs)
• coeffs/numbers.cc (modified) (1 diff)
• polys/ext_fields/algext.cc (modified) (3 diffs)
• polys/monomials/ring.cc (modified) (1 diff)
• polys/monomials/ring.h (modified) (1 diff)
• tests/coeffs_test.h (modified) (1 diff)
• tests/polys_test.h (modified) (3 diffs)

libpolys/coeffs/coeffs.h

@@ -45 +45 @@
 typedef struct snumber *   number;
 
-struct snumber;
-typedef struct snumber *   number;
-
 /* standard types */
 #ifdef HAVE_RINGS
@@ -58 +55 @@
 
 struct n_Procs_s;
-typedef struct  n_Procs_s  n_Procs_s;
 typedef struct  n_Procs_s  *coeffs;
 
@@ -182 +178 @@
 //-------------------------------------------
 
-  /// For Zp_a, Q_a we need polynomials (due to polys)
-  ring          algring; //< implementation of extensions needs polynomials...
-  // // for Q_a/Zp_a, rInit
+  /* for extension fields we need to be able to represent polynomials,
+     so here is the polynomial ring: */
+  ring          algring;
+
   //number     minpoly;  //< no longer needed: replaced by
   //                     //<  algring->minideal->[0]
@@ -222 +219 @@
                      intermediate extension fields, i.e., in this case
                      it is redundant along the chain of field extensions;
-                     CONTRARY to SINGULAR as it was, we do NOT LONGER use
-                     negative values for ch. */
+                     CONTRARY to SINGULAR as it was, we do NO LONGER use
+                     negative values for ch;
+                     for rings, ch will also be set and is - per def -
+                     the smallest number of 1's that sum up to zero;
+                     however, in this case ch may not fit in an int,
+                     thus ch may contain a faulty value */
 
   short      float_len; /* additional char-flags, rInit */
@@ -233 +234 @@
   // for n_GF
 
-  int m_nfCharQ;  ///< the number of elemts: q
+  int m_nfCharQ;  ///< the number of elements: q
   int m_nfM1;       ///< representation of -1
   int m_nfCharP;  ///< the characteristic: p
@@ -438 +439 @@
 
 static inline BOOLEAN nCoeff_is_Zp(const coeffs r, int p)
-{ assume(r != NULL); return (getCoeffType(r)  && (r->ch == ABS(p))); }
+{ assume(r != NULL); return (getCoeffType(r)  && (r->ch == p)); }
 
 static inline BOOLEAN nCoeff_is_Q(const coeffs r)
@@ -447 +448 @@
 // (r->ringtype == 0) && (r->ch ==  -1); ??
 
-
 static inline BOOLEAN nCoeff_is_R(const coeffs r)
 { assume(r != NULL); return getCoeffType(r)==n_R; }
@@ -457 +457 @@
 { assume(r != NULL); return (getCoeffType(r)==n_GF) && (r->ch == q); }
 
-/* TRUE iff an extension tower is build upon some Zp, i.e., the bottom
-   field in this tower is Zp */
+/* TRUE iff r represents an algebraic or transcendental extension field */
+static inline BOOLEAN nCoeff_is_Extension(const coeffs r)
+{
+  assume(r != NULL);
+  return (getCoeffType(r)==n_algExt) || (getCoeffType(r)==n_transExt);
+}
+
+/* DO NOT USE (only kept for compatibility reasons towards the SINGULAR
+   svn trunk);
+   intension: should be TRUE iff the given r is an extension field above
+   some Z/pZ;
+   actually: TRUE iff the given r is an extension tower of arbitrary
+   height above some field of characteristic p (may be Z/pZ or some
+   Galois field of characteristic p) */
 static inline BOOLEAN nCoeff_is_Zp_a(const coeffs r)
 {
   assume(r != NULL);
-  return (r->ringtype == 0) &&
-         ((getCoeffType(r)==n_algExt) || (getCoeffType(r)==n_transExt)) &&
-         (r->ch != 0);
-}
-
-/* TRUE iff an extension tower is build upon Zp (p as provided), i.e.,
-   the bottom field in this tower is Zp */
+  return ((r->ringtype == 0) && (r->ch != 0) && nCoeff_is_Extension(r));
+}
+
+/* DO NOT USE (only kept for compatibility reasons towards the SINGULAR
+   svn trunk);
+   intension: should be TRUE iff the given r is an extension field above
+   Z/pZ (with p as provided);
+   actually: TRUE iff the given r is an extension tower of arbitrary
+   height above some field of characteristic p (may be Z/pZ or some
+   Galois field of characteristic p) */
 static inline BOOLEAN nCoeff_is_Zp_a(const coeffs r, int p)
 {
   assume(r != NULL);
-  return (r->ringtype == 0) &&
-         ((getCoeffType(r)==n_algExt) || (getCoeffType(r)==n_transExt)) &&
-         (r->ch != 0) && (r->ch == p);
-}
-
-/* TRUE iff an extension tower is build upon Q, i.e.,
-   the bottom field in this tower is Q */
+  return ((r->ringtype == 0) && (r->ch == p) && nCoeff_is_Extension(r));
+}
+
+/* DO NOT USE (only kept for compatibility reasons towards the SINGULAR
+   svn trunk);
+   intension: should be TRUE iff the given r is an extension field
+   above Q;
+   actually: TRUE iff the given r is an extension tower of arbitrary
+   height above some field of characteristic 0 (may be Q, R, or C) */
 static inline BOOLEAN nCoeff_is_Q_a(const coeffs r)
 {
   assume(r != NULL);
-  return (r->ringtype == 0) &&
-         ((getCoeffType(r)==n_algExt) || (getCoeffType(r)==n_transExt)) &&
-         (r->ch == 0);
+  return ((r->ringtype == 0) && (r->ch == 0) && nCoeff_is_Extension(r));
 }
 
@@ -507 +522 @@
 // #endif
 
-
-
 /// TRUE if n_Delete/n_New are empty operations
 static inline BOOLEAN nCoeff_has_simple_Alloc(const coeffs r)
@@ -520 +533 @@
 //             || rField_is_R(r)); }
 
-/* TRUE iff r represents an algebraic or transcendental extension field */
-static inline BOOLEAN nCoeff_is_Extension(const coeffs r)
-{
-  assume(r != NULL);
-  return (getCoeffType(r)==n_algExt) || (getCoeffType(r)==n_transExt);
-}
-
 /* TRUE iff r represents an algebraic extension field */
 static inline BOOLEAN nCoeff_is_algExt(const coeffs r)

libpolys/coeffs/numbers.cc

@@ -74 +74 @@
 {
   int c = n_GetChar(r);
-printf("### c = %d\n", c);
   BOOLEAN ret = n_IsZero(a, r);
   if( (c != 0) && !ret )

libpolys/polys/ext_fields/algext.cc

@@ -87 +87 @@
 void definiteReduce(poly &p, poly reducer, const coeffs cf);
 
+/* returns the bottom field in this field extension tower; if the tower
+   is flat, i.e., if there is no extension, then r itself is returned;
+   as a side-effect, the counter 'height' is filled with the height of
+   the extension tower (in case the tower is flat, 'height' is zero) */
+static coeffs nCoeff_bottom(const coeffs r, int &height)
+{
+  assume(r != NULL);
+  coeffs cf = r;
+  height = 0;
+  while (nCoeff_is_Extension(cf))
+  {
+    assume(cf->algring != NULL); assume(cf->algring->cf != NULL);
+    cf = cf->algring->cf;
+    height++;
+  }
+  return cf;
+}
+
 BOOLEAN naIsZero(number a, const coeffs cf)
 {
@@ -526 +544 @@
 nMapFunc naSetMap(const coeffs src, const coeffs dst)
 {
-  /* dst is expected to be an algebraic extension field */
+  /* dst is expected to be an algebraic field extension */
   assume(getCoeffType(dst) == n_algExt);
   
-  /* ATTENTION: This code assumes that dst is an algebraic extension of Q
-                or Zp. So, dst must NOT BE an algebraic extension of some
-                extension etc. This code will NOT WORK for extension
-                towers of height >= 2. */
-  
-  if (nCoeff_is_Q(src) && nCoeff_is_Q_a(dst))
+  int h = 0; /* the height of the extension tower given by dst */
+  coeffs bDst = nCoeff_bottom(dst, h); /* the bottom field in the tower dst */
+  
+  /* for the time being, we only provide maps if h = 1 and if b is Q or
+     some field Z/pZ: */
+  if (h != 1) return NULL;
+  if ((!nCoeff_is_Zp(bDst)) && (!nCoeff_is_Q(bDst))) return NULL;
+  
+  if (nCoeff_is_Q(src) && nCoeff_is_Q(bDst))
     return naMap00;                                      /// Q     -->  Q(a)
   
-  if (nCoeff_is_Zp(src) && nCoeff_is_Q_a(dst))
+  if (nCoeff_is_Zp(src) && nCoeff_is_Q(bDst))
     return naMapP0;                                      /// Z/p   -->  Q(a)
   
-  if (nCoeff_is_Q_a(src) && nCoeff_is_Q_a(dst))
+  if (nCoeff_is_Q(src) && nCoeff_is_Zp(bDst))
+    return naMap0P;                                      /// Q      --> Z/p(a)
+  
+  if (nCoeff_is_Zp(src) && nCoeff_is_Zp(bDst))
+  {
+    if (src->ch == dst->ch) return naMapPP;              /// Z/p    --> Z/p(a)
+    else return naMapUP;                                 /// Z/u    --> Z/p(a)
+  }
+  
+  coeffs bSrc = nCoeff_bottom(src, h); /* the bottom field in the tower src */
+  if (h != 1) return NULL;
+  if ((!nCoeff_is_Zp(bSrc)) && (!nCoeff_is_Q(bSrc))) return NULL;
+  
+  if (nCoeff_is_Q(bSrc) && nCoeff_is_Q(bDst))
   {
     if (strcmp(rParameter(src->algring)[0],
@@ -549 +583 @@
   }
   
-  if (nCoeff_is_Q(src) && nCoeff_is_Zp_a(dst))
-    return naMap0P;                                      /// Q      --> Z/p(a)
-  
-  if (nCoeff_is_Zp(src) && nCoeff_is_Zp_a(dst))
-  {
-    if (src->ch == dst->ch) return naMapPP;              /// Z/p    --> Z/p(a)
-    else return naMapUP;                                 /// Z/u    --> Z/p(a)
-  }
-  
-  if (nCoeff_is_Zp_a(src) && nCoeff_is_Zp_a(dst))
+  if (nCoeff_is_Zp(bSrc) && nCoeff_is_Zp(bDst))
   {
     if (strcmp(rParameter(src->algring)[0],

libpolys/polys/monomials/ring.cc

@@ -736 +736 @@
 }
 
-int rChar(ring r)
-{
-  TODO(Somabody, move this proc. over to coeffs!?);
-
-#ifdef HAVE_RINGS
-  if (rField_is_Ring_2toM(r))
-    return binaryPower(2, (int)(unsigned long)r->cf->modExponent);
-  if (rField_is_Ring_ModN(r))
-    return (int)mpz_get_ui(r->cf->modBase);
-  if (rField_is_Ring_PtoM(r))
-    return binaryPower((int)mpz_get_ui(r->cf->modBase),
-                       (int)(unsigned long)r->cf->modExponent);
-
-#endif
-  if (rField_is_numeric(r))
-    return 0;
-  if (!rIsExtension(r)) /* Q, Fp */
-    return r->cf->ch;
-  if (rField_is_Zp_a(r))  /* Fp(a)  */
-    return -r->cf->ch;
-  if (rField_is_Q_a(r))   /* Q(a)  */
-    return 0;
-  /*else*/               /* GF(p,n) */
-  {
-    if ((r->cf->ch & 1)==0) return 2;
-    int i=3;
-    while ((r->cf->ch % i)!=0) i+=2;
-    return i;
-  }
-}
+/* we keep this otherwise superfluous method for compatibility reasons
+   towards the SINGULAR svn trunk */
+int rChar(ring r) { return r->cf->ch; }
 
 typedef char *             char_ptr;

libpolys/polys/monomials/ring.h

@@ -470 +470 @@
 { assume(r != NULL); return nCoeff_is_GF(r->cf, q); }
 
+/* DO NOT USE; just here for compatibility reasons towards
+   the SINGULAR svn trunk */
 static inline BOOLEAN rField_is_Zp_a(const ring r)
 { assume(r != NULL); return nCoeff_is_Zp_a(r->cf); }
 
+/* DO NOT USE; just here for compatibility reasons towards
+   the SINGULAR svn trunk */
 static inline BOOLEAN rField_is_Zp_a(const ring r, int p)
 { assume(r != NULL); return nCoeff_is_Zp_a(r->cf, p); }
 
+/* DO NOT USE; just here for compatibility reasons towards
+   the SINGULAR svn trunk */
 static inline BOOLEAN rField_is_Q_a(const ring r)
 { assume(r != NULL); return nCoeff_is_Q_a(r->cf); }

libpolys/tests/coeffs_test.h

@@ -278 +278 @@
       TS_ASSERT( !nCoeff_is_numeric( r ));
       TS_ASSERT( !nCoeff_is_R( r ));
-      TS_ASSERT( !nCoeff_is_Q_a( r ));
-      TS_ASSERT( !nCoeff_is_Zp_a( r ));
       TS_ASSERT( !nCoeff_is_GF( r ));
       TS_ASSERT( !nCoeff_is_long_R( r ));

libpolys/tests/polys_test.h

@@ -584 +584 @@
     TS_ASSERT( nCoeff_is_algExt(cf) );
     TS_ASSERT( !nCoeff_is_transExt(cf) );
-    TS_ASSERT( nCoeff_is_Q_a(cf) );
-    TS_ASSERT( !nCoeff_is_Zp_a(cf) );
     
     // some tests for the coefficient field represented by cf:
@@ -687 +685 @@
     TS_ASSERT( nCoeff_is_algExt(cf) );
     TS_ASSERT( !nCoeff_is_transExt(cf) );
-    TS_ASSERT( nCoeff_is_Q_a(cf) );
-    TS_ASSERT( !nCoeff_is_Zp_a(cf) );
     
     // some tests for the coefficient field represented by cf:
@@ -833 +829 @@
     TS_ASSERT( nCoeff_is_algExt(cf) );
     TS_ASSERT( !nCoeff_is_transExt(cf) );
-    TS_ASSERT( !nCoeff_is_Q_a(cf) );
-    TS_ASSERT( nCoeff_is_Zp_a(cf) );
     
     // some tests for the coefficient field represented by cf: