Changeset f63dbca in git for factory/cf_gcd.cc

Timestamp:

Jul 8, 1996, 10:21:10 AM (27 years ago)

Author:

Rüdiger Stobbe <stobbe@…>

Branches:

(u'spielwiese', 'a719bcf0b8dbc648b128303a49777a094b57592c')

Children:

7b4bfe63f5e8232ccce6c9f00ab9238ceabc1041

Parents:

d675c7716d78a6d5c5238c8820480fc2f09a860e

Message:

"gcd_poly: now uses ezgcd if the switch SW_USE_EZGCD is on.
"


git-svn-id: file:///usr/local/Singular/svn/trunk@39 2c84dea3-7e68-4137-9b89-c4e89433aadc

File:

• factory/cf_gcd.cc (modified) (8 diffs)

factory/cf_gcd.cc

@@ -1 +1 @@
 // emacs edit mode for this file is -*- C++ -*-
-// $Id: cf_gcd.cc,v 1.3 1996-06-18 12:22:54 stobbe Exp $
+// $Id: cf_gcd.cc,v 1.4 1996-07-08 08:21:10 stobbe Exp $
 
 /*
 $Log: not supported by cvs2svn $
+Revision 1.3  1996/06/18 12:22:54  stobbe
+"gcd_poly_univar0: now uses getSmallPrimes (due to changes in the handling
+                  of prime numbers in cf_primes.
+"
+
 Revision 1.2  1996/06/13 08:18:34  stobbe
 "balance: Now balaces polynomials even if the coefficient sizes are higher
@@ -31 +36 @@
 #include "cf_primes.h"
 #include "cf_chinese.h"
+#include "cf_map.h"
+#include "fac_util.h"
 #include "templates/functions.h"
 
@@ -51 +58 @@
 }
 
-static bool
-gcd_test_one ( const CanonicalForm & f, const CanonicalForm & g )
+bool
+gcd_test_one ( const CanonicalForm & f, const CanonicalForm & g, bool swap )
 {
     int count = 0;
     // assume polys have same level;
     CFRandom * sample = CFRandomFactory::generate();
-    REvaluation e( 2, f.level(), *sample );
+    REvaluation e( 2, tmax( f.level(), g.level() ), *sample );
     delete sample;
-    CanonicalForm lcf = swapvar( LC( f ), Variable(1), f.mvar() );
-    CanonicalForm lcg = swapvar( LC( g ), Variable(1), f.mvar() );
+    CanonicalForm lcf, lcg;
+    if ( swap ) {
+        lcf = swapvar( LC( f ), Variable(1), f.mvar() );
+        lcg = swapvar( LC( g ), Variable(1), f.mvar() );
+    }
+    else {
+        lcf = LC( f, Variable(1) );
+        lcg = LC( g, Variable(1) );
+    }
     while ( ( e( lcf ).isZero() || e( lcg ).isZero() ) && count < 100 ) {
         e.nextpoint();
@@ -67 +81 @@
     if ( count == 100 )
         return false;
-    CanonicalForm F=swapvar( f, Variable(1), f.mvar() );
-    CanonicalForm G=swapvar( g, Variable(1), g.mvar() );
+    CanonicalForm F, G;
+    if ( swap ) {
+        F=swapvar( f, Variable(1), f.mvar() );
+        G=swapvar( g, Variable(1), g.mvar() );
+    }
+    else {
+        F = f;
+        G = g;
+    }
     if ( e(F).taildegree() > 0 && e(G).taildegree() > 0 )
         return false;
@@ -291 +312 @@
         if ( i >= 0 ) {
             // now balance D mod q
-            D = pp( balance( cg * D, q ) );
+            D = pp( balance( D, q ) );
             if ( divides( D, f ) && divides( D, g ) )
                 return D * c;
@@ -300 +321 @@
             return gcd_poly( F, G, false );
         }
-    }
-}
-
-
-static CanonicalForm
-gcd_poly( const CanonicalForm & f, const CanonicalForm& g, bool modularflag )
+        cerr << "another try ..." << endl;
+    }
+}
+
+
+static CanonicalForm
+gcd_poly1( const CanonicalForm & f, const CanonicalForm & g, bool modularflag )
 {
     CanonicalForm C, Ci, Ci1, Hi, bi, pi, pi1, pi2;
@@ -325 +347 @@
     }
     else
-        if ( gcd_test_one( pi1, pi ) )
+        if ( gcd_test_one( pi1, pi, true ) )
             return C;
     delta = degree( pi, v ) - degree( pi1, v );
@@ -353 +375 @@
 }
 
+
+static CanonicalForm
+gcd_poly( const CanonicalForm & f, const CanonicalForm & g, bool modularflag )
+{
+    if ( isOn( SW_USE_EZGCD ) && ! ( f.isUnivariate() && g.isUnivariate() ) ) {
+        CFMap M, N;
+        compress( f, g, M, N );
+        return N( ezgcd( M(f), M(g) ) );
+    }
+    else {
+        return gcd_poly1( f, g, modularflag );
+    }
+}
+    
 
 static CanonicalForm