Changeset 12f6ce0 in git for libpolys/polys/ext_fields

Timestamp:

Aug 22, 2013, 3:35:23 PM (11 years ago)

Author:

Janko Boehm <boehm@…>

Branches:

(u'spielwiese', '2a584933abf2a2d3082034c7586d38bb6de1a30a')

Children:

5d258e90f0942cca8fc2fed57ff1d4c5ecdbc20a

Parents:

2e4ee2b73c0c10b254963f2c5bb24ce6688d1f5b

git-author:

Janko Boehm <boehm@mathematik.uni-kl.de>2013-08-22 15:35:23+02:00

git-committer:

Janko Boehm <boehm@mathematik.uni-kl.de>2013-09-03 19:36:11+02:00

Message:

Added differentiation of coefficients in transcendental extensions

Location:

libpolys/polys/ext_fields

Files:

• transext.cc (modified) (3 diffs)
• transext.h (modified) (1 diff)

libpolys/polys/ext_fields/transext.cc

@@ -33 +33 @@
 *           TODO: the description above needs a major update!!!
 */
+
+
+
+
+
 #define TRANSEXT_PRIVATES
 
@@ -67 +72 @@
 #define ADD_COMPLEXITY 1   /**< complexity increase due to + and - */
 #define MULT_COMPLEXITY 2   /**< complexity increase due to * and / */
+#define DIFF_COMPLEXITY 2   /**< complexity increase due to * and / */
 #define BOUND_COMPLEXITY 10   /**< maximum complexity of a number */
 
@@ -740 +746 @@
 */
 }
+
+number ntDiff(number a, number d, const coeffs cf)
+{
+  ntTest(a);
+  ntTest(d);
+
+  fraction t = (fraction) d;
+  if (!DENIS1(t))
+  {
+    WerrorS("expected differentiation by a variable");
+    return a;
+  }
+  int k=p_Var(NUM(t),ntRing);
+  if (k==0)
+  {
+    WerrorS("expected differentiation by a variable");
+    return a;
+  }
+
+  if (IS0(a)) return ntCopy(a, cf);
+
+  fraction fa = (fraction)a;
+
+  poly g = p_Copy(NUM(fa), ntRing);
+  poly f = p_Copy(DEN(fa), ntRing);
+  poly dg =p_Diff(g,k,ntRing);
+
+  if (DENIS1(fa)) {
+
+     fraction result = (fraction)omAlloc0Bin(fractionObjectBin);
+     NUM(result) = dg;
+     DEN(result) = NULL;
+     COM(result) = COM(fa);
+     return (number)result;
+  }
+
+  poly df =p_Diff(f,k,ntRing);
+  fraction result = (fraction)omAlloc0Bin(fractionObjectBin);
+  poly fg = p_Mult_q(p_Copy(f,ntRing),dg,ntRing);
+  poly gf = p_Neg(p_Mult_q(g,df,ntRing),ntRing);
+  NUM(result) = p_Add_q(fg,gf,ntRing);
+  DEN(result) = p_Mult_q(p_Copy(f,ntRing), f, ntRing);
+  COM(result) = COM(fa) + COM(fa) + DIFF_COMPLEXITY;
+  heuristicGcdCancellation((number)result, cf);
+
+  return (number)result;
+}
+
 
 number ntAdd(number a, number b, const coeffs cf)

libpolys/polys/ext_fields/transext.h

@@ -98 +98 @@
 BOOLEAN  ntInitChar(coeffs cf, void* infoStruct);
 
+number ntDiff(number a, number d, const coeffs cf);
+
 /* Private hidden interface
 BOOLEAN  ntGreaterZero(number a, const coeffs cf);