Changeset 010f3b in git

Timestamp:

Jun 29, 2011, 5:54:28 PM (12 years ago)

Author:

Frank Seelisch <seelisch@…>

Branches:

(u'jengelh-datetime', 'ceac47cbc86fe4a15902392bdbb9bd2ae0ea02c6')(u'spielwiese', 'a800fe4b3e9d37a38c5a10cc0ae9dfa0c15a4ee6')

Children:

df43d9eede47de2604d4c0ff334af81427c1ec57

Parents:

de90c019d739dd11bb7004ab4f6d1147833c69bc

git-author:

Frank Seelisch <seelisch@mathematik.uni-kl.de>2011-06-29 17:54:28+02:00

git-committer:

Mohamed Barakat <mohamed.barakat@rwth-aachen.de>2011-11-09 12:39:10+01:00

Message:

more tests for transcendental case

Location:

libpolys

Files:

• polys/ext_fields/transext.cc (modified) (8 diffs)
• polys/ext_fields/transext.h (modified) (1 diff)
• tests/polys_test.h (modified) (2 diffs)

libpolys/polys/ext_fields/transext.cc

@@ -66 +66 @@
 
 void heuristicGcdCancellation(number a, const coeffs cf);
-void definiteGcdCancellation(number a, const coeffs cf);
+void definiteGcdCancellation(number a, const coeffs cf,
+                             BOOLEAN skipSimpleTests);
 
 #ifdef LDEBUG
@@ -175 +176 @@
 {
   ntTest(a);
-  definiteGcdCancellation(a, cf);
+  definiteGcdCancellation(a, cf, FALSE);
   if (is0(a)) return NULL;
   fraction f = (fraction)a;
@@ -189 +190 @@
 {
   ntTest(a);
-  definiteGcdCancellation(a, cf);
+  definiteGcdCancellation(a, cf, FALSE);
   fraction f = (fraction)a;
   poly g;
@@ -204 +205 @@
 {
   ntTest(a);
-  definiteGcdCancellation(a, cf);
-  fraction f = (fraction)a;
-  if (!denIs1(f)) return FALSE;
-  poly g = num(f);
-  if (!p_IsConstant(g, ntRing)) return FALSE;
-  return n_IsOne(p_GetCoeff(g, ntRing), ntCoeffs);
+  definiteGcdCancellation(a, cf, FALSE);
+  fraction f = (fraction)a;
+  return denIs1(f) && numIs1(f);
 }
 
@@ -215 +213 @@
 {
   ntTest(a);
-  definiteGcdCancellation(a, cf);
+  definiteGcdCancellation(a, cf, FALSE);
   fraction f = (fraction)a;
   if (!denIs1(f)) return FALSE;
@@ -258 +256 @@
   ntTest(a);
   if (is0(a)) return 0;
-  definiteGcdCancellation(a, cf);
+  definiteGcdCancellation(a, cf, FALSE);
   fraction f = (fraction)a;
   if (!denIs1(f)) return 0;
@@ -532 +530 @@
   ntTest(a);
   if (is0(a)) return;
-  fraction f = (fraction)a;
-  if (denIs1(f) || n_IsOne(p_GetCoeff(num(f), ntRing), ntCoeffs))
-  { c(f) = 0; return; }
+  
+  fraction f = (fraction)a;
+  if (denIs1(f) || numIs1(f)) { c(f) = 0; return; }
+  
+  /* check whether num(f) = den(f), and - if so - replace 'a' by 1 */
+  poly difference = p_Add_q(p_Copy(num(f), ntRing),
+                            p_Neg(p_Copy(den(f), ntRing), ntRing),
+                            ntRing);
+  if (difference == NULL)
+  { /* we also know that numerator and denominator are both != 1 */
+    p_Delete(&num(f), ntRing); num(f) = p_ISet(1, ntRing);
+    p_Delete(&den(f), ntRing); den(f) = NULL;
+    c(f) = 0;
+    return;
+  }
+  else p_Delete(&difference, ntRing);
+  
   if (c(f) <= BOUND_COMPLEXITY) return;
-  else definiteGcdCancellation(a, cf);
+  else definiteGcdCancellation(a, cf, TRUE);
 }
 
 /* modifies a */
-void definiteGcdCancellation(number a, const coeffs cf)
-{
-  ntTest(a);
-  if (is0(a)) return;
-  fraction f = (fraction)a;
-  if (denIs1(f) || n_IsOne(p_GetCoeff(num(f), ntRing), ntCoeffs))
-  { c(f) = 0; return; }
-  if (c(f) > BOUND_COMPLEXITY)
-  {
-    /* TO BE IMPLEMENTED!
-       for the time, cancellation of gcd's does not take place */
-    Print("// TO BE IMPLEMENTED: transext.cc:definiteGcdCancellation\n");
-    Print("// (complexity of number = %d exceeds the bound = %d\n",
-          c(f), BOUND_COMPLEXITY);
-  }
+void definiteGcdCancellation(number a, const coeffs cf,
+                             BOOLEAN skipSimpleTests)
+{
+  ntTest(a);
+  
+  fraction f = (fraction)a;
+  
+  if (!skipSimpleTests)
+  {
+    if (is0(a)) return;
+    if (denIs1(f) || numIs1(f)) { c(f) = 0; return; }
+  
+    /* check whether num(f) = den(f), and - if so - replace 'a' by 1 */
+    poly difference = p_Add_q(p_Copy(num(f), ntRing),
+                              p_Neg(p_Copy(den(f), ntRing), ntRing),
+                              ntRing);
+    if (difference == NULL)
+    { /* we also know that numerator and denominator are both != 1 */
+      p_Delete(&num(f), ntRing); num(f) = p_ISet(1, ntRing);
+      p_Delete(&den(f), ntRing); den(f) = NULL;
+      c(f) = 0;
+      return;
+    }
+    else p_Delete(&difference, ntRing);
+  }
+  
+  /* TO BE IMPLEMENTED!
+     for the time being, cancellation of gcd's does not take place */
+  Print("// TO BE IMPLEMENTED: transext.cc:definiteGcdCancellation\n");
+  Print("// (complexity of number = %d, bound = %d)\n",
+        c(f), BOUND_COMPLEXITY);
 }
 
@@ -560 +588 @@
 {
   ntTest(a);
-  definiteGcdCancellation(a, cf);
+  definiteGcdCancellation(a, cf, FALSE);
   if (is0(a))
     StringAppendS("0");

libpolys/polys/ext_fields/transext.h

@@ -63 +63 @@
 #define den(f) f->denominator
 #define denIs1(f) (f->denominator == NULL) /**< TRUE iff den. represents 1 */
+#define numIs1(f) (p_IsConstant(f->numerator, cf->extRing) && \
+                   n_IsOne(p_GetCoeff(num(f), cf->extRing), cf->extRing->cf))
+                   /**< TRUE iff num. represents 1 */
 #define c(f) f->complexity
 

libpolys/tests/polys_test.h

@@ -231 +231 @@
     TS_ASSERT( n_IsOne(n2, cf) );
     n_Delete(&n1, cf); n_Delete(&n2, cf);
+  }
+  /* assumes that cf represents a rational function field;
+     does NOT copy p, i.e. uses p directly inside the resulting number */
+  number toFractionNumber(poly p, const coeffs cf)
+  {
+    number n = n_Init(1, cf);
+    fraction f = (fraction)n;
+    p_Delete(&(f->numerator), cf->extRing);
+    f->numerator = p;
+    return n;
   }
   void TestArithCf(const coeffs r)
@@ -933 +943 @@
     Test(s);
     
+    /* some special tests: */
+    poly v1 = NULL;
+    plusTerm(v1, 1, 1, 1, cf->extRing);       // s
+    plusTerm(v1, 1, 1, 0, cf->extRing);       // s + 1
+    poly v2 = NULL;
+    plusTerm(v2, 1, 1, 1, cf->extRing);       // s
+    plusTerm(v2, 2, 2, 1, cf->extRing);       // s + 2t
+    poly v = p_Mult_q(v1, v2, cf->extRing);   // (s + 1) * (s + 2t)
+    number v_n = toFractionNumber(v, cf);
+    PrintSized(v_n, cf);
+    poly w = NULL;
+    plusTerm(w, 1, 1, 1, cf->extRing);        // s
+    plusTerm(w, 1, 1, 0, cf->extRing);        // s + 1
+    number w_n = toFractionNumber(w, cf);
+    PrintSized(w_n, cf);
+    number vOverW_n = n_Div(v_n, w_n, cf);
+    PrintSized(vOverW_n, cf);
+    number wOverV_n = n_Invers(vOverW_n, cf);
+    PrintSized(wOverV_n, cf);
+    number prod = n_Mult(vOverW_n, wOverV_n, cf);
+    PrintSized(prod, cf);
+    number tmp; number nn = n_Copy(vOverW_n, cf);
+    for (int i = 1; i <= 20; i++)
+    {
+      tmp = n_Div(nn, v_n, cf);
+      n_Delete(&nn, cf);
+      nn = tmp;
+      clog << i << ". "; PrintSized(nn, cf);
+    }
+    n_Delete(&prod, cf); n_Delete(&nn, cf);
+    n_Delete(&v_n, cf); n_Delete(&w_n, cf);
+    n_Delete(&vOverW_n, cf); n_Delete(&wOverV_n, cf);
+    
     rDelete(s); // kills 'cf' and 'r' as well
   }