X-Git-Url: https://ginac.de/CLN/cln.git//cln.git?a=blobdiff_plain;f=src%2Ffloat%2Ftranscendental%2Fcl_LF_zeta3.cc;h=4e56cfe8d04e1e0ed3930972af3a49e8a40bf999;hb=3af2cde18b3aabed4c808b0113daa81c2263b0bd;hp=0455da5e36b28df06dd26419f01c85c849d59edb;hpb=dd9e0f894eec7e2a8cf85078330ddc0a6639090b;p=cln.git

diff --git a/src/float/transcendental/cl_LF_zeta3.cc b/src/float/transcendental/cl_LF_zeta3.cc
index 0455da5..4e56cfe 100644
--- a/src/float/transcendental/cl_LF_zeta3.cc
+++ b/src/float/transcendental/cl_LF_zeta3.cc
@@ -1,24 +1,47 @@
-// cl_zeta3().
+// zeta3().
 
 // General includes.
-#include "cl_sysdep.h"
+#include "base/cl_sysdep.h"
 
 // Specification.
-#include "cl_F_tran.h"
+#include "float/transcendental/cl_F_tran.h"
 
 
 // Implementation.
 
-#include "cl_lfloat.h"
-#include "cl_LF_tran.h"
-#include "cl_LF.h"
-#include "cl_integer.h"
-#include "cl_alloca.h"
+#include "cln/lfloat.h"
+#include "float/transcendental/cl_LF_tran.h"
+#include "float/lfloat/cl_LF.h"
+#include "cln/integer.h"
+#include "base/cl_alloca.h"
 
-const cl_LF cl_zeta3 (uintC len)
+namespace cln {
+
+const cl_LF zeta3 (uintC len)
 {
+	struct rational_series_stream : cl_pqa_series_stream {
+		uintC n;
+		static cl_pqa_series_term computenext (cl_pqa_series_stream& thisss)
+		{
+			var rational_series_stream& thiss = (rational_series_stream&)thisss;
+			var uintC n = thiss.n;
+			var cl_pqa_series_term result;
+			if (n==0) {
+				result.p = 1;
+			} else {
+				result.p = -expt_pos(n,5);
+			}
+			result.q = expt_pos(2*n+1,5)<<5;
+			result.a = 205*square((cl_I)n) + 250*(cl_I)n + 77;
+			thiss.n = n+1;
+			return result;
+		}
+		rational_series_stream ()
+			: cl_pqa_series_stream (rational_series_stream::computenext),
+			  n (0) {}
+	} series;
 	// Method:
-	//            /infinity                                  \ 
+	//            /infinity                                  \ 
 	//            | -----       (n + 1)       2              |
 	//        1   |  \      (-1)        (205 n  - 160 n + 32)|
 	//        -   |   )     ---------------------------------|
@@ -27,40 +50,19 @@ const cl_LF cl_zeta3 (uintC len)
 	//            \ n = 1                                    /
 	//
 	// The formula used to compute Zeta(3) has reference in the paper
-	// "Acceleration of Hypergeometric Series via the WZ method" by
-	// T. Amdeberhan and Doron Zeilberger, to appear in the Electronic
-	// Journal of Combinatorics [Wilf Festschrift Volume].
+	// "Hypergeometric Series Acceleration via the WZ method" by
+	// T. Amdeberhan and Doron Zeilberger,
+	// Electronic J. Combin. 4 (1997), R3.
 	//
 	// Computation of the sum:
 	// Evaluate a sum(0 <= n < N, a(n)/b(n) * (p(0)...p(n))/(q(0)...q(n)))
 	// with appropriate N, and
 	//   a(n) = 205*n^2+250*n+77, b(n) = 1,
 	//   p(0) = 1, p(n) = -n^5 for n>0, q(n) = 32*(2n+1)^5.
-	var uintC actuallen = len+2; // 2 Schutz-Digits
-	var uintL N = ceiling(actuallen*intDsize,10);
+	var uintC actuallen = len+2; // 2 guard digits
+	var uintC N = ceiling(actuallen*intDsize,10);
 	// 1024^-N <= 2^(-intDsize*actuallen).
-	CL_ALLOCA_STACK;
-	var cl_I* av = (cl_I*) cl_alloca(N*sizeof(cl_I));
-	var cl_I* pv = (cl_I*) cl_alloca(N*sizeof(cl_I));
-	var cl_I* qv = (cl_I*) cl_alloca(N*sizeof(cl_I));
-	var uintL n;
-	for (n = 0; n < N; n++) {
-		init1(cl_I, av[n]) (205*square((cl_I)n) + 250*(cl_I)n + 77);
-		if (n==0)
-			init1(cl_I, pv[n]) (1);
-		else
-			init1(cl_I, pv[n]) (-expt_pos(n,5));
-		init1(cl_I, qv[n]) (expt_pos(2*n+1,5)<<5);
-	}
-	var cl_pqa_series series;
-	series.av = av;
-	series.pv = pv; series.qv = qv; series.qsv = NULL;
-	var cl_LF sum = eval_rational_series(N,series,actuallen);
-	for (n = 0; n < N; n++) {
-		av[n].~cl_I();
-		pv[n].~cl_I();
-		qv[n].~cl_I();
-	}
+	var cl_LF sum = eval_rational_series<false>(N,series,actuallen,actuallen);
 	return scale_float(shorten(sum,len),-1);
 }
 // Bit complexity (N := len): O(log(N)^2*M(N)).
@@ -81,3 +83,5 @@ const cl_LF cl_zeta3 (uintC len)
 // 50000                          3723
 // asymp.    FAST     N^2    FAST    FAST
 // (FAST means O(log(N)^2*M(N)))
+
+}  // namespace cln