Changeset 7d1c995 in git for factory/algext.cc

Timestamp:

May 31, 2011, 3:48:35 PM (12 years ago)

Author:

Martin Lee <martinlee84@…>

Branches:

(u'spielwiese', '8e0ad00ce244dfd0756200662572aef8402f13d5')

Children:

a8e8b95ce901a8a52041639c48329ebc09efae2b

Parents:

5b274570b3977c8b95131bdda194e0b179f17b8b

Message:

added test to prevent multiple inclusion of headers
moved function declarations from fieldGCD.h to algext.h
deleted broken routine univarQGCD 


git-svn-id: file:///usr/local/Singular/svn/trunk@14253 2c84dea3-7e68-4137-9b89-c4e89433aadc

File:

• factory/algext.cc (modified) (1 diff)

factory/algext.cc

@@ -145 +145 @@
   return false;
 }
-
-CanonicalForm univarQGCD( const CanonicalForm & F, const CanonicalForm & G )
-{ // F,G in Q(a)[x]
-  CanonicalForm f, g, tmp, M, q, D, Dp, cl, newD, newq;
-  int p, dp_deg, bound, i;
-  bool fail;
-  On(SW_RATIONAL);
-  f = F * bCommonDen(F);
-  g = G * bCommonDen(G);
-  Variable a,b;
-  if( !hasFirstAlgVar( f, a ) && !hasFirstAlgVar( g, b ))
-  {
-    // F and G are in Q[x], call...
-#ifdef HAVE_NTL
-    if ( isOn( SW_USE_NTL_GCD_0 ))
-      return gcd_univar_ntl0( f, g );
-#endif
-    return gcd_poly_univar0( f, g, false );
-  }
-  if( b.level() > a.level() )
-    a = b;
-  // here: a is the biggest alg. var in f and g
-  tmp = getMipo(a);
-  M = tmp * bCommonDen(tmp);
-  Off(SW_RATIONAL);
-  // calculate upper bound for degree of gcd
-  bound = degree(f);
-  i = degree(g);
-  if( i < bound )
-    bound = i;
-
-  cl = lc(M) * lc(f) * lc(g);
-  q = 1;
-  D = 0;
-  for(i=cf_getNumBigPrimes()-1; i>-1; i--)
-  {
-    p = cf_getBigPrime(i);
-    if( mod( cl, p ).isZero() ) // skip lc-bad primes
-      continue;
-
-    fail = false;
-    setCharacteristic(p);
-    tryEuclid( mapinto(f), mapinto(g), mapinto(M), Dp, fail );
-    setCharacteristic(0);
-    if( fail ) // M splits in char p
-      continue;
-
-    dp_deg = degree(Dp);
-
-    if( dp_deg == 0 ) // early termination
-    {
-      CanonicalForm inv;
-      tryInvert(Dp, M, inv, fail);
-      if(fail)
-        continue;
-      return CanonicalForm(1);
-    }
-
-    if( dp_deg > bound ) // current prime unlucky
-      continue;
-
-    if( dp_deg < bound ) // all previous primes unlucky
-    {
-      q = p;
-      D = mapinto(Dp); // shortcut CRA
-      bound = dp_deg; // tighten bound
-      continue;
-    }
-    chineseRemainder( D, q, mapinto(Dp), p, newD, newq );
-    // newD = Dp mod p
-    // newD = D mod q
-    // newq = p*q
-    q = newq;
-    if( D != newD )
-    {
-      D = newD;
-      continue;
-    }
-    On( SW_RATIONAL );
-    tmp = Farey( D, q );
-    if( fdivides( tmp, f ) && fdivides( tmp, g )) // trial division
-    {
-      Off( SW_RATIONAL );
-      return tmp;
-    }
-    Off( SW_RATIONAL );
-  }
-  // hopefully, we never reach this point
-  Off( SW_USE_QGCD );
-  D = gcd( f, g );
-  On( SW_USE_QGCD );
-  return D;
-}
-
-
 
 CanonicalForm QGCD( const CanonicalForm & F, const CanonicalForm & G );