Mercurial > hg > vamp-build-and-test
comparison DEPENDENCIES/generic/include/boost/math/constants/calculate_constants.hpp @ 16:2665513ce2d3
Add boost headers
author | Chris Cannam |
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date | Tue, 05 Aug 2014 11:11:38 +0100 |
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children | c530137014c0 |
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1 // Copyright John Maddock 2010, 2012. | |
2 // Copyright Paul A. Bristow 2011, 2012. | |
3 | |
4 // Use, modification and distribution are subject to the | |
5 // Boost Software License, Version 1.0. (See accompanying file | |
6 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) | |
7 | |
8 #ifndef BOOST_MATH_CALCULATE_CONSTANTS_CONSTANTS_INCLUDED | |
9 #define BOOST_MATH_CALCULATE_CONSTANTS_CONSTANTS_INCLUDED | |
10 | |
11 #include <boost/math/special_functions/trunc.hpp> | |
12 | |
13 namespace boost{ namespace math{ namespace constants{ namespace detail{ | |
14 | |
15 template <class T> | |
16 template<int N> | |
17 inline T constant_pi<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
18 { | |
19 BOOST_MATH_STD_USING | |
20 | |
21 return ldexp(acos(T(0)), 1); | |
22 | |
23 /* | |
24 // Although this code works well, it's usually more accurate to just call acos | |
25 // and access the number types own representation of PI which is usually calculated | |
26 // at slightly higher precision... | |
27 | |
28 T result; | |
29 T a = 1; | |
30 T b; | |
31 T A(a); | |
32 T B = 0.5f; | |
33 T D = 0.25f; | |
34 | |
35 T lim; | |
36 lim = boost::math::tools::epsilon<T>(); | |
37 | |
38 unsigned k = 1; | |
39 | |
40 do | |
41 { | |
42 result = A + B; | |
43 result = ldexp(result, -2); | |
44 b = sqrt(B); | |
45 a += b; | |
46 a = ldexp(a, -1); | |
47 A = a * a; | |
48 B = A - result; | |
49 B = ldexp(B, 1); | |
50 result = A - B; | |
51 bool neg = boost::math::sign(result) < 0; | |
52 if(neg) | |
53 result = -result; | |
54 if(result <= lim) | |
55 break; | |
56 if(neg) | |
57 result = -result; | |
58 result = ldexp(result, k - 1); | |
59 D -= result; | |
60 ++k; | |
61 lim = ldexp(lim, 1); | |
62 } | |
63 while(true); | |
64 | |
65 result = B / D; | |
66 return result; | |
67 */ | |
68 } | |
69 | |
70 template <class T> | |
71 template<int N> | |
72 inline T constant_two_pi<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
73 { | |
74 return 2 * pi<T, policies::policy<policies::digits2<N> > >(); | |
75 } | |
76 | |
77 template <class T> // 2 / pi | |
78 template<int N> | |
79 inline T constant_two_div_pi<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
80 { | |
81 return 2 / pi<T, policies::policy<policies::digits2<N> > >(); | |
82 } | |
83 | |
84 template <class T> // sqrt(2/pi) | |
85 template <int N> | |
86 inline T constant_root_two_div_pi<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
87 { | |
88 BOOST_MATH_STD_USING | |
89 return sqrt((2 / pi<T, policies::policy<policies::digits2<N> > >())); | |
90 } | |
91 | |
92 template <class T> | |
93 template<int N> | |
94 inline T constant_one_div_two_pi<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
95 { | |
96 return 1 / two_pi<T, policies::policy<policies::digits2<N> > >(); | |
97 } | |
98 | |
99 template <class T> | |
100 template<int N> | |
101 inline T constant_root_pi<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
102 { | |
103 BOOST_MATH_STD_USING | |
104 return sqrt(pi<T, policies::policy<policies::digits2<N> > >()); | |
105 } | |
106 | |
107 template <class T> | |
108 template<int N> | |
109 inline T constant_root_half_pi<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
110 { | |
111 BOOST_MATH_STD_USING | |
112 return sqrt(pi<T, policies::policy<policies::digits2<N> > >() / 2); | |
113 } | |
114 | |
115 template <class T> | |
116 template<int N> | |
117 inline T constant_root_two_pi<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
118 { | |
119 BOOST_MATH_STD_USING | |
120 return sqrt(two_pi<T, policies::policy<policies::digits2<N> > >()); | |
121 } | |
122 | |
123 template <class T> | |
124 template<int N> | |
125 inline T constant_log_root_two_pi<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
126 { | |
127 BOOST_MATH_STD_USING | |
128 return log(root_two_pi<T, policies::policy<policies::digits2<N> > >()); | |
129 } | |
130 | |
131 template <class T> | |
132 template<int N> | |
133 inline T constant_root_ln_four<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
134 { | |
135 BOOST_MATH_STD_USING | |
136 return sqrt(log(static_cast<T>(4))); | |
137 } | |
138 | |
139 template <class T> | |
140 template<int N> | |
141 inline T constant_e<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
142 { | |
143 // | |
144 // Although we can clearly calculate this from first principles, this hooks into | |
145 // T's own notion of e, which hopefully will more accurate than one calculated to | |
146 // a few epsilon: | |
147 // | |
148 BOOST_MATH_STD_USING | |
149 return exp(static_cast<T>(1)); | |
150 } | |
151 | |
152 template <class T> | |
153 template<int N> | |
154 inline T constant_half<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
155 { | |
156 return static_cast<T>(1) / static_cast<T>(2); | |
157 } | |
158 | |
159 template <class T> | |
160 template<int M> | |
161 inline T constant_euler<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<M>)) | |
162 { | |
163 BOOST_MATH_STD_USING | |
164 // | |
165 // This is the method described in: | |
166 // "Some New Algorithms for High-Precision Computation of Euler's Constant" | |
167 // Richard P Brent and Edwin M McMillan. | |
168 // Mathematics of Computation, Volume 34, Number 149, Jan 1980, pages 305-312. | |
169 // See equation 17 with p = 2. | |
170 // | |
171 T n = 3 + (M ? (std::min)(M, tools::digits<T>()) : tools::digits<T>()) / 4; | |
172 T lim = M ? ldexp(T(1), 1 - (std::min)(M, tools::digits<T>())) : tools::epsilon<T>(); | |
173 T lnn = log(n); | |
174 T term = 1; | |
175 T N = -lnn; | |
176 T D = 1; | |
177 T Hk = 0; | |
178 T one = 1; | |
179 | |
180 for(unsigned k = 1;; ++k) | |
181 { | |
182 term *= n * n; | |
183 term /= k * k; | |
184 Hk += one / k; | |
185 N += term * (Hk - lnn); | |
186 D += term; | |
187 | |
188 if(term < D * lim) | |
189 break; | |
190 } | |
191 return N / D; | |
192 } | |
193 | |
194 template <class T> | |
195 template<int N> | |
196 inline T constant_euler_sqr<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
197 { | |
198 BOOST_MATH_STD_USING | |
199 return euler<T, policies::policy<policies::digits2<N> > >() | |
200 * euler<T, policies::policy<policies::digits2<N> > >(); | |
201 } | |
202 | |
203 template <class T> | |
204 template<int N> | |
205 inline T constant_one_div_euler<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
206 { | |
207 BOOST_MATH_STD_USING | |
208 return static_cast<T>(1) | |
209 / euler<T, policies::policy<policies::digits2<N> > >(); | |
210 } | |
211 | |
212 | |
213 template <class T> | |
214 template<int N> | |
215 inline T constant_root_two<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
216 { | |
217 BOOST_MATH_STD_USING | |
218 return sqrt(static_cast<T>(2)); | |
219 } | |
220 | |
221 | |
222 template <class T> | |
223 template<int N> | |
224 inline T constant_root_three<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
225 { | |
226 BOOST_MATH_STD_USING | |
227 return sqrt(static_cast<T>(3)); | |
228 } | |
229 | |
230 template <class T> | |
231 template<int N> | |
232 inline T constant_half_root_two<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
233 { | |
234 BOOST_MATH_STD_USING | |
235 return sqrt(static_cast<T>(2)) / 2; | |
236 } | |
237 | |
238 template <class T> | |
239 template<int N> | |
240 inline T constant_ln_two<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
241 { | |
242 // | |
243 // Although there are good ways to calculate this from scratch, this hooks into | |
244 // T's own notion of log(2) which will hopefully be accurate to the full precision | |
245 // of T: | |
246 // | |
247 BOOST_MATH_STD_USING | |
248 return log(static_cast<T>(2)); | |
249 } | |
250 | |
251 template <class T> | |
252 template<int N> | |
253 inline T constant_ln_ten<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
254 { | |
255 BOOST_MATH_STD_USING | |
256 return log(static_cast<T>(10)); | |
257 } | |
258 | |
259 template <class T> | |
260 template<int N> | |
261 inline T constant_ln_ln_two<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
262 { | |
263 BOOST_MATH_STD_USING | |
264 return log(log(static_cast<T>(2))); | |
265 } | |
266 | |
267 template <class T> | |
268 template<int N> | |
269 inline T constant_third<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
270 { | |
271 BOOST_MATH_STD_USING | |
272 return static_cast<T>(1) / static_cast<T>(3); | |
273 } | |
274 | |
275 template <class T> | |
276 template<int N> | |
277 inline T constant_twothirds<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
278 { | |
279 BOOST_MATH_STD_USING | |
280 return static_cast<T>(2) / static_cast<T>(3); | |
281 } | |
282 | |
283 template <class T> | |
284 template<int N> | |
285 inline T constant_two_thirds<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
286 { | |
287 BOOST_MATH_STD_USING | |
288 return static_cast<T>(2) / static_cast<T>(3); | |
289 } | |
290 | |
291 template <class T> | |
292 template<int N> | |
293 inline T constant_three_quarters<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
294 { | |
295 BOOST_MATH_STD_USING | |
296 return static_cast<T>(3) / static_cast<T>(4); | |
297 } | |
298 | |
299 template <class T> | |
300 template<int N> | |
301 inline T constant_pi_minus_three<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
302 { | |
303 return pi<T, policies::policy<policies::digits2<N> > >() - static_cast<T>(3); | |
304 } | |
305 | |
306 template <class T> | |
307 template<int N> | |
308 inline T constant_four_minus_pi<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
309 { | |
310 return static_cast<T>(4) - pi<T, policies::policy<policies::digits2<N> > >(); | |
311 } | |
312 | |
313 template <class T> | |
314 template<int N> | |
315 inline T constant_pow23_four_minus_pi<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
316 { | |
317 BOOST_MATH_STD_USING | |
318 return pow(four_minus_pi<T, policies::policy<policies::digits2<N> > >(), static_cast<T>(1.5)); | |
319 } | |
320 | |
321 template <class T> | |
322 template<int N> | |
323 inline T constant_exp_minus_half<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
324 { | |
325 BOOST_MATH_STD_USING | |
326 return exp(static_cast<T>(-0.5)); | |
327 } | |
328 | |
329 // Pi | |
330 template <class T> | |
331 template<int N> | |
332 inline T constant_one_div_root_two<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
333 { | |
334 return static_cast<T>(1) / root_two<T, policies::policy<policies::digits2<N> > >(); | |
335 } | |
336 | |
337 template <class T> | |
338 template<int N> | |
339 inline T constant_one_div_root_pi<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
340 { | |
341 return static_cast<T>(1) / root_pi<T, policies::policy<policies::digits2<N> > >(); | |
342 } | |
343 | |
344 template <class T> | |
345 template<int N> | |
346 inline T constant_one_div_root_two_pi<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
347 { | |
348 return static_cast<T>(1) / root_two_pi<T, policies::policy<policies::digits2<N> > >(); | |
349 } | |
350 | |
351 template <class T> | |
352 template<int N> | |
353 inline T constant_root_one_div_pi<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
354 { | |
355 BOOST_MATH_STD_USING | |
356 return sqrt(static_cast<T>(1) / pi<T, policies::policy<policies::digits2<N> > >()); | |
357 } | |
358 | |
359 | |
360 template <class T> | |
361 template<int N> | |
362 inline T constant_four_thirds_pi<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
363 { | |
364 BOOST_MATH_STD_USING | |
365 return pi<T, policies::policy<policies::digits2<N> > >() * static_cast<T>(4) / static_cast<T>(3); | |
366 } | |
367 | |
368 template <class T> | |
369 template<int N> | |
370 inline T constant_half_pi<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
371 { | |
372 BOOST_MATH_STD_USING | |
373 return pi<T, policies::policy<policies::digits2<N> > >() / static_cast<T>(2); | |
374 } | |
375 | |
376 | |
377 template <class T> | |
378 template<int N> | |
379 inline T constant_third_pi<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
380 { | |
381 BOOST_MATH_STD_USING | |
382 return pi<T, policies::policy<policies::digits2<N> > >() / static_cast<T>(3); | |
383 } | |
384 | |
385 template <class T> | |
386 template<int N> | |
387 inline T constant_sixth_pi<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
388 { | |
389 BOOST_MATH_STD_USING | |
390 return pi<T, policies::policy<policies::digits2<N> > >() / static_cast<T>(6); | |
391 } | |
392 | |
393 template <class T> | |
394 template<int N> | |
395 inline T constant_two_thirds_pi<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
396 { | |
397 BOOST_MATH_STD_USING | |
398 return pi<T, policies::policy<policies::digits2<N> > >() * static_cast<T>(2) / static_cast<T>(3); | |
399 } | |
400 | |
401 template <class T> | |
402 template<int N> | |
403 inline T constant_three_quarters_pi<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
404 { | |
405 BOOST_MATH_STD_USING | |
406 return pi<T, policies::policy<policies::digits2<N> > >() * static_cast<T>(3) / static_cast<T>(4); | |
407 } | |
408 | |
409 template <class T> | |
410 template<int N> | |
411 inline T constant_pi_pow_e<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
412 { | |
413 BOOST_MATH_STD_USING | |
414 return pow(pi<T, policies::policy<policies::digits2<N> > >(), e<T, policies::policy<policies::digits2<N> > >()); // | |
415 } | |
416 | |
417 template <class T> | |
418 template<int N> | |
419 inline T constant_pi_sqr<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
420 { | |
421 BOOST_MATH_STD_USING | |
422 return pi<T, policies::policy<policies::digits2<N> > >() | |
423 * pi<T, policies::policy<policies::digits2<N> > >() ; // | |
424 } | |
425 | |
426 template <class T> | |
427 template<int N> | |
428 inline T constant_pi_sqr_div_six<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
429 { | |
430 BOOST_MATH_STD_USING | |
431 return pi<T, policies::policy<policies::digits2<N> > >() | |
432 * pi<T, policies::policy<policies::digits2<N> > >() | |
433 / static_cast<T>(6); // | |
434 } | |
435 | |
436 | |
437 template <class T> | |
438 template<int N> | |
439 inline T constant_pi_cubed<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
440 { | |
441 BOOST_MATH_STD_USING | |
442 return pi<T, policies::policy<policies::digits2<N> > >() | |
443 * pi<T, policies::policy<policies::digits2<N> > >() | |
444 * pi<T, policies::policy<policies::digits2<N> > >() | |
445 ; // | |
446 } | |
447 | |
448 template <class T> | |
449 template<int N> | |
450 inline T constant_cbrt_pi<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
451 { | |
452 BOOST_MATH_STD_USING | |
453 return pow(pi<T, policies::policy<policies::digits2<N> > >(), static_cast<T>(1)/ static_cast<T>(3)); | |
454 } | |
455 | |
456 template <class T> | |
457 template<int N> | |
458 inline T constant_one_div_cbrt_pi<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
459 { | |
460 BOOST_MATH_STD_USING | |
461 return static_cast<T>(1) | |
462 / pow(pi<T, policies::policy<policies::digits2<N> > >(), static_cast<T>(1)/ static_cast<T>(3)); | |
463 } | |
464 | |
465 // Euler's e | |
466 | |
467 template <class T> | |
468 template<int N> | |
469 inline T constant_e_pow_pi<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
470 { | |
471 BOOST_MATH_STD_USING | |
472 return pow(e<T, policies::policy<policies::digits2<N> > >(), pi<T, policies::policy<policies::digits2<N> > >()); // | |
473 } | |
474 | |
475 template <class T> | |
476 template<int N> | |
477 inline T constant_root_e<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
478 { | |
479 BOOST_MATH_STD_USING | |
480 return sqrt(e<T, policies::policy<policies::digits2<N> > >()); | |
481 } | |
482 | |
483 template <class T> | |
484 template<int N> | |
485 inline T constant_log10_e<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
486 { | |
487 BOOST_MATH_STD_USING | |
488 return log10(e<T, policies::policy<policies::digits2<N> > >()); | |
489 } | |
490 | |
491 template <class T> | |
492 template<int N> | |
493 inline T constant_one_div_log10_e<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
494 { | |
495 BOOST_MATH_STD_USING | |
496 return static_cast<T>(1) / | |
497 log10(e<T, policies::policy<policies::digits2<N> > >()); | |
498 } | |
499 | |
500 // Trigonometric | |
501 | |
502 template <class T> | |
503 template<int N> | |
504 inline T constant_degree<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
505 { | |
506 BOOST_MATH_STD_USING | |
507 return pi<T, policies::policy<policies::digits2<N> > >() | |
508 / static_cast<T>(180) | |
509 ; // | |
510 } | |
511 | |
512 template <class T> | |
513 template<int N> | |
514 inline T constant_radian<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
515 { | |
516 BOOST_MATH_STD_USING | |
517 return static_cast<T>(180) | |
518 / pi<T, policies::policy<policies::digits2<N> > >() | |
519 ; // | |
520 } | |
521 | |
522 template <class T> | |
523 template<int N> | |
524 inline T constant_sin_one<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
525 { | |
526 BOOST_MATH_STD_USING | |
527 return sin(static_cast<T>(1)) ; // | |
528 } | |
529 | |
530 template <class T> | |
531 template<int N> | |
532 inline T constant_cos_one<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
533 { | |
534 BOOST_MATH_STD_USING | |
535 return cos(static_cast<T>(1)) ; // | |
536 } | |
537 | |
538 template <class T> | |
539 template<int N> | |
540 inline T constant_sinh_one<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
541 { | |
542 BOOST_MATH_STD_USING | |
543 return sinh(static_cast<T>(1)) ; // | |
544 } | |
545 | |
546 template <class T> | |
547 template<int N> | |
548 inline T constant_cosh_one<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
549 { | |
550 BOOST_MATH_STD_USING | |
551 return cosh(static_cast<T>(1)) ; // | |
552 } | |
553 | |
554 template <class T> | |
555 template<int N> | |
556 inline T constant_phi<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
557 { | |
558 BOOST_MATH_STD_USING | |
559 return (static_cast<T>(1) + sqrt(static_cast<T>(5)) )/static_cast<T>(2) ; // | |
560 } | |
561 | |
562 template <class T> | |
563 template<int N> | |
564 inline T constant_ln_phi<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
565 { | |
566 BOOST_MATH_STD_USING | |
567 //return log(phi<T, policies::policy<policies::digits2<N> > >()); // ??? | |
568 return log((static_cast<T>(1) + sqrt(static_cast<T>(5)) )/static_cast<T>(2) ); | |
569 } | |
570 template <class T> | |
571 template<int N> | |
572 inline T constant_one_div_ln_phi<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
573 { | |
574 BOOST_MATH_STD_USING | |
575 return static_cast<T>(1) / | |
576 log((static_cast<T>(1) + sqrt(static_cast<T>(5)) )/static_cast<T>(2) ); | |
577 } | |
578 | |
579 // Zeta | |
580 | |
581 template <class T> | |
582 template<int N> | |
583 inline T constant_zeta_two<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
584 { | |
585 BOOST_MATH_STD_USING | |
586 | |
587 return pi<T, policies::policy<policies::digits2<N> > >() | |
588 * pi<T, policies::policy<policies::digits2<N> > >() | |
589 /static_cast<T>(6); | |
590 } | |
591 | |
592 template <class T> | |
593 template<int N> | |
594 inline T constant_zeta_three<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
595 { | |
596 // http://mathworld.wolfram.com/AperysConstant.html | |
597 // http://en.wikipedia.org/wiki/Mathematical_constant | |
598 | |
599 // http://oeis.org/A002117/constant | |
600 //T zeta3("1.20205690315959428539973816151144999076" | |
601 // "4986292340498881792271555341838205786313" | |
602 // "09018645587360933525814619915"); | |
603 | |
604 //"1.202056903159594285399738161511449990, 76498629234049888179227155534183820578631309018645587360933525814619915" A002117 | |
605 // 1.202056903159594285399738161511449990, 76498629234049888179227155534183820578631309018645587360933525814619915780, +00); | |
606 //"1.2020569031595942 double | |
607 // http://www.spaennare.se/SSPROG/ssnum.pdf // section 11, Algorithm for Apery's constant zeta(3). | |
608 // Programs to Calculate some Mathematical Constants to Large Precision, Document Version 1.50 | |
609 | |
610 // by Stefan Spannare September 19, 2007 | |
611 // zeta(3) = 1/64 * sum | |
612 BOOST_MATH_STD_USING | |
613 T n_fact=static_cast<T>(1); // build n! for n = 0. | |
614 T sum = static_cast<double>(77); // Start with n = 0 case. | |
615 // for n = 0, (77/1) /64 = 1.203125 | |
616 //double lim = std::numeric_limits<double>::epsilon(); | |
617 T lim = N ? ldexp(T(1), 1 - (std::min)(N, tools::digits<T>())) : tools::epsilon<T>(); | |
618 for(unsigned int n = 1; n < 40; ++n) | |
619 { // three to five decimal digits per term, so 40 should be plenty for 100 decimal digits. | |
620 //cout << "n = " << n << endl; | |
621 n_fact *= n; // n! | |
622 T n_fact_p10 = n_fact * n_fact * n_fact * n_fact * n_fact * n_fact * n_fact * n_fact * n_fact * n_fact; // (n!)^10 | |
623 T num = ((205 * n * n) + (250 * n) + 77) * n_fact_p10; // 205n^2 + 250n + 77 | |
624 // int nn = (2 * n + 1); | |
625 // T d = factorial(nn); // inline factorial. | |
626 T d = 1; | |
627 for(unsigned int i = 1; i <= (n+n + 1); ++i) // (2n + 1) | |
628 { | |
629 d *= i; | |
630 } | |
631 T den = d * d * d * d * d; // [(2n+1)!]^5 | |
632 //cout << "den = " << den << endl; | |
633 T term = num/den; | |
634 if (n % 2 != 0) | |
635 { //term *= -1; | |
636 sum -= term; | |
637 } | |
638 else | |
639 { | |
640 sum += term; | |
641 } | |
642 //cout << "term = " << term << endl; | |
643 //cout << "sum/64 = " << sum/64 << endl; | |
644 if(abs(term) < lim) | |
645 { | |
646 break; | |
647 } | |
648 } | |
649 return sum / 64; | |
650 } | |
651 | |
652 template <class T> | |
653 template<int N> | |
654 inline T constant_catalan<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
655 { // http://oeis.org/A006752/constant | |
656 //T c("0.915965594177219015054603514932384110774" | |
657 //"149374281672134266498119621763019776254769479356512926115106248574"); | |
658 | |
659 // 9.159655941772190150546035149323841107, 74149374281672134266498119621763019776254769479356512926115106248574422619, -01); | |
660 | |
661 // This is equation (entry) 31 from | |
662 // http://www-2.cs.cmu.edu/~adamchik/articles/catalan/catalan.htm | |
663 // See also http://www.mpfr.org/algorithms.pdf | |
664 BOOST_MATH_STD_USING | |
665 T k_fact = 1; | |
666 T tk_fact = 1; | |
667 T sum = 1; | |
668 T term; | |
669 T lim = N ? ldexp(T(1), 1 - (std::min)(N, tools::digits<T>())) : tools::epsilon<T>(); | |
670 | |
671 for(unsigned k = 1;; ++k) | |
672 { | |
673 k_fact *= k; | |
674 tk_fact *= (2 * k) * (2 * k - 1); | |
675 term = k_fact * k_fact / (tk_fact * (2 * k + 1) * (2 * k + 1)); | |
676 sum += term; | |
677 if(term < lim) | |
678 { | |
679 break; | |
680 } | |
681 } | |
682 return boost::math::constants::pi<T, boost::math::policies::policy<> >() | |
683 * log(2 + boost::math::constants::root_three<T, boost::math::policies::policy<> >()) | |
684 / 8 | |
685 + 3 * sum / 8; | |
686 } | |
687 | |
688 namespace khinchin_detail{ | |
689 | |
690 template <class T> | |
691 T zeta_polynomial_series(T s, T sc, int digits) | |
692 { | |
693 BOOST_MATH_STD_USING | |
694 // | |
695 // This is algorithm 3 from: | |
696 // | |
697 // "An Efficient Algorithm for the Riemann Zeta Function", P. Borwein, | |
698 // Canadian Mathematical Society, Conference Proceedings, 2000. | |
699 // See: http://www.cecm.sfu.ca/personal/pborwein/PAPERS/P155.pdf | |
700 // | |
701 BOOST_MATH_STD_USING | |
702 int n = (digits * 19) / 53; | |
703 T sum = 0; | |
704 T two_n = ldexp(T(1), n); | |
705 int ej_sign = 1; | |
706 for(int j = 0; j < n; ++j) | |
707 { | |
708 sum += ej_sign * -two_n / pow(T(j + 1), s); | |
709 ej_sign = -ej_sign; | |
710 } | |
711 T ej_sum = 1; | |
712 T ej_term = 1; | |
713 for(int j = n; j <= 2 * n - 1; ++j) | |
714 { | |
715 sum += ej_sign * (ej_sum - two_n) / pow(T(j + 1), s); | |
716 ej_sign = -ej_sign; | |
717 ej_term *= 2 * n - j; | |
718 ej_term /= j - n + 1; | |
719 ej_sum += ej_term; | |
720 } | |
721 return -sum / (two_n * (1 - pow(T(2), sc))); | |
722 } | |
723 | |
724 template <class T> | |
725 T khinchin(int digits) | |
726 { | |
727 BOOST_MATH_STD_USING | |
728 T sum = 0; | |
729 T term; | |
730 T lim = ldexp(T(1), 1-digits); | |
731 T factor = 0; | |
732 unsigned last_k = 1; | |
733 T num = 1; | |
734 for(unsigned n = 1;; ++n) | |
735 { | |
736 for(unsigned k = last_k; k <= 2 * n - 1; ++k) | |
737 { | |
738 factor += num / k; | |
739 num = -num; | |
740 } | |
741 last_k = 2 * n; | |
742 term = (zeta_polynomial_series(T(2 * n), T(1 - T(2 * n)), digits) - 1) * factor / n; | |
743 sum += term; | |
744 if(term < lim) | |
745 break; | |
746 } | |
747 return exp(sum / boost::math::constants::ln_two<T, boost::math::policies::policy<> >()); | |
748 } | |
749 | |
750 } | |
751 | |
752 template <class T> | |
753 template<int N> | |
754 inline T constant_khinchin<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
755 { | |
756 int n = N ? (std::min)(N, tools::digits<T>()) : tools::digits<T>(); | |
757 return khinchin_detail::khinchin<T>(n); | |
758 } | |
759 | |
760 template <class T> | |
761 template<int N> | |
762 inline T constant_extreme_value_skewness<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
763 { // from e_float constants.cpp | |
764 // Mathematica: N[12 Sqrt[6] Zeta[3]/Pi^3, 1101] | |
765 BOOST_MATH_STD_USING | |
766 T ev(12 * sqrt(static_cast<T>(6)) * zeta_three<T, policies::policy<policies::digits2<N> > >() | |
767 / pi_cubed<T, policies::policy<policies::digits2<N> > >() ); | |
768 | |
769 //T ev( | |
770 //"1.1395470994046486574927930193898461120875997958365518247216557100852480077060706857071875468869385150" | |
771 //"1894272048688553376986765366075828644841024041679714157616857834895702411080704529137366329462558680" | |
772 //"2015498788776135705587959418756809080074611906006528647805347822929577145038743873949415294942796280" | |
773 //"0895597703063466053535550338267721294164578901640163603544404938283861127819804918174973533694090594" | |
774 //"3094963822672055237678432023017824416203652657301470473548274848068762500300316769691474974950757965" | |
775 //"8640779777748741897542093874605477776538884083378029488863880220988107155275203245233994097178778984" | |
776 //"3488995668362387892097897322246698071290011857605809901090220903955815127463328974447572119951192970" | |
777 //"3684453635456559086126406960279692862247058250100678008419431185138019869693206366891639436908462809" | |
778 //"9756051372711251054914491837034685476095423926553367264355374652153595857163724698198860485357368964" | |
779 //"3807049634423621246870868566707915720704996296083373077647528285782964567312903914752617978405994377" | |
780 //"9064157147206717895272199736902453130842229559980076472936976287378945035706933650987259357729800315"); | |
781 | |
782 return ev; | |
783 } | |
784 | |
785 namespace detail{ | |
786 // | |
787 // Calculation of the Glaisher constant depends upon calculating the | |
788 // derivative of the zeta function at 2, we can then use the relation: | |
789 // zeta'(2) = 1/6 pi^2 [euler + ln(2pi)-12ln(A)] | |
790 // To get the constant A. | |
791 // See equation 45 at http://mathworld.wolfram.com/RiemannZetaFunction.html. | |
792 // | |
793 // The derivative of the zeta function is computed by direct differentiation | |
794 // of the relation: | |
795 // (1-2^(1-s))zeta(s) = SUM(n=0, INF){ (-n)^n / (n+1)^s } | |
796 // Which gives us 2 slowly converging but alternating sums to compute, | |
797 // for this we use Algorithm 1 from "Convergent Acceleration of Alternating Series", | |
798 // Henri Cohen, Fernando Rodriguez Villegas and Don Zagier, Experimental Mathematics 9:1 (1999). | |
799 // See http://www.math.utexas.edu/users/villegas/publications/conv-accel.pdf | |
800 // | |
801 template <class T> | |
802 T zeta_series_derivative_2(unsigned digits) | |
803 { | |
804 // Derivative of the series part, evaluated at 2: | |
805 BOOST_MATH_STD_USING | |
806 int n = digits * 301 * 13 / 10000; | |
807 boost::math::itrunc((std::numeric_limits<T>::digits10 + 1) * 1.3); | |
808 T d = pow(3 + sqrt(T(8)), n); | |
809 d = (d + 1 / d) / 2; | |
810 T b = -1; | |
811 T c = -d; | |
812 T s = 0; | |
813 for(int k = 0; k < n; ++k) | |
814 { | |
815 T a = -log(T(k+1)) / ((k+1) * (k+1)); | |
816 c = b - c; | |
817 s = s + c * a; | |
818 b = (k + n) * (k - n) * b / ((k + T(0.5f)) * (k + 1)); | |
819 } | |
820 return s / d; | |
821 } | |
822 | |
823 template <class T> | |
824 T zeta_series_2(unsigned digits) | |
825 { | |
826 // Series part of zeta at 2: | |
827 BOOST_MATH_STD_USING | |
828 int n = digits * 301 * 13 / 10000; | |
829 T d = pow(3 + sqrt(T(8)), n); | |
830 d = (d + 1 / d) / 2; | |
831 T b = -1; | |
832 T c = -d; | |
833 T s = 0; | |
834 for(int k = 0; k < n; ++k) | |
835 { | |
836 T a = T(1) / ((k + 1) * (k + 1)); | |
837 c = b - c; | |
838 s = s + c * a; | |
839 b = (k + n) * (k - n) * b / ((k + T(0.5f)) * (k + 1)); | |
840 } | |
841 return s / d; | |
842 } | |
843 | |
844 template <class T> | |
845 inline T zeta_series_lead_2() | |
846 { | |
847 // lead part at 2: | |
848 return 2; | |
849 } | |
850 | |
851 template <class T> | |
852 inline T zeta_series_derivative_lead_2() | |
853 { | |
854 // derivative of lead part at 2: | |
855 return -2 * boost::math::constants::ln_two<T>(); | |
856 } | |
857 | |
858 template <class T> | |
859 inline T zeta_derivative_2(unsigned n) | |
860 { | |
861 // zeta derivative at 2: | |
862 return zeta_series_derivative_2<T>(n) * zeta_series_lead_2<T>() | |
863 + zeta_series_derivative_lead_2<T>() * zeta_series_2<T>(n); | |
864 } | |
865 | |
866 } // namespace detail | |
867 | |
868 template <class T> | |
869 template<int N> | |
870 inline T constant_glaisher<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
871 { | |
872 | |
873 BOOST_MATH_STD_USING | |
874 typedef policies::policy<policies::digits2<N> > forwarding_policy; | |
875 int n = N ? (std::min)(N, tools::digits<T>()) : tools::digits<T>(); | |
876 T v = detail::zeta_derivative_2<T>(n); | |
877 v *= 6; | |
878 v /= boost::math::constants::pi<T, forwarding_policy>() * boost::math::constants::pi<T, forwarding_policy>(); | |
879 v -= boost::math::constants::euler<T, forwarding_policy>(); | |
880 v -= log(2 * boost::math::constants::pi<T, forwarding_policy>()); | |
881 v /= -12; | |
882 return exp(v); | |
883 | |
884 /* | |
885 // from http://mpmath.googlecode.com/svn/data/glaisher.txt | |
886 // 20,000 digits of the Glaisher-Kinkelin constant A = exp(1/2 - zeta'(-1)) | |
887 // Computed using A = exp((6 (-zeta'(2))/pi^2 + log 2 pi + gamma)/12) | |
888 // with Euler-Maclaurin summation for zeta'(2). | |
889 T g( | |
890 "1.282427129100622636875342568869791727767688927325001192063740021740406308858826" | |
891 "46112973649195820237439420646120399000748933157791362775280404159072573861727522" | |
892 "14334327143439787335067915257366856907876561146686449997784962754518174312394652" | |
893 "76128213808180219264516851546143919901083573730703504903888123418813674978133050" | |
894 "93770833682222494115874837348064399978830070125567001286994157705432053927585405" | |
895 "81731588155481762970384743250467775147374600031616023046613296342991558095879293" | |
896 "36343887288701988953460725233184702489001091776941712153569193674967261270398013" | |
897 "52652668868978218897401729375840750167472114895288815996668743164513890306962645" | |
898 "59870469543740253099606800842447417554061490189444139386196089129682173528798629" | |
899 "88434220366989900606980888785849587494085307347117090132667567503310523405221054" | |
900 "14176776156308191919997185237047761312315374135304725819814797451761027540834943" | |
901 "14384965234139453373065832325673954957601692256427736926358821692159870775858274" | |
902 "69575162841550648585890834128227556209547002918593263079373376942077522290940187"); | |
903 | |
904 return g; | |
905 */ | |
906 } | |
907 | |
908 template <class T> | |
909 template<int N> | |
910 inline T constant_rayleigh_skewness<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
911 { // From e_float | |
912 // 1100 digits of the Rayleigh distribution skewness | |
913 // Mathematica: N[2 Sqrt[Pi] (Pi - 3)/((4 - Pi)^(3/2)), 1100] | |
914 | |
915 BOOST_MATH_STD_USING | |
916 T rs(2 * root_pi<T, policies::policy<policies::digits2<N> > >() | |
917 * pi_minus_three<T, policies::policy<policies::digits2<N> > >() | |
918 / pow(four_minus_pi<T, policies::policy<policies::digits2<N> > >(), static_cast<T>(3./2)) | |
919 ); | |
920 // 6.31110657818937138191899351544227779844042203134719497658094585692926819617473725459905027032537306794400047264, | |
921 | |
922 //"0.6311106578189371381918993515442277798440422031347194976580945856929268196174737254599050270325373067" | |
923 //"9440004726436754739597525250317640394102954301685809920213808351450851396781817932734836994829371322" | |
924 //"5797376021347531983451654130317032832308462278373358624120822253764532674177325950686466133508511968" | |
925 //"2389168716630349407238090652663422922072397393006683401992961569208109477307776249225072042971818671" | |
926 //"4058887072693437217879039875871765635655476241624825389439481561152126886932506682176611183750503553" | |
927 //"1218982627032068396407180216351425758181396562859085306247387212297187006230007438534686340210168288" | |
928 //"8956816965453815849613622117088096547521391672977226658826566757207615552041767516828171274858145957" | |
929 //"6137539156656005855905288420585194082284972984285863898582313048515484073396332610565441264220790791" | |
930 //"0194897267890422924599776483890102027823328602965235306539844007677157873140562950510028206251529523" | |
931 //"7428049693650605954398446899724157486062545281504433364675815915402937209673727753199567661561209251" | |
932 //"4695589950526053470201635372590001578503476490223746511106018091907936826431407434894024396366284848"); ; | |
933 return rs; | |
934 } | |
935 | |
936 template <class T> | |
937 template<int N> | |
938 inline T constant_rayleigh_kurtosis_excess<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
939 { // - (6 Pi^2 - 24 Pi + 16)/((Pi - 4)^2) | |
940 // Might provide and calculate this using pi_minus_four. | |
941 BOOST_MATH_STD_USING | |
942 return - (((static_cast<T>(6) * pi<T, policies::policy<policies::digits2<N> > >() | |
943 * pi<T, policies::policy<policies::digits2<N> > >()) | |
944 - (static_cast<T>(24) * pi<T, policies::policy<policies::digits2<N> > >()) + static_cast<T>(16) ) | |
945 / | |
946 ((pi<T, policies::policy<policies::digits2<N> > >() - static_cast<T>(4)) | |
947 * (pi<T, policies::policy<policies::digits2<N> > >() - static_cast<T>(4))) | |
948 ); | |
949 } | |
950 | |
951 template <class T> | |
952 template<int N> | |
953 inline T constant_rayleigh_kurtosis<T>::compute(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(mpl::int_<N>)) | |
954 { // 3 - (6 Pi^2 - 24 Pi + 16)/((Pi - 4)^2) | |
955 // Might provide and calculate this using pi_minus_four. | |
956 BOOST_MATH_STD_USING | |
957 return static_cast<T>(3) - (((static_cast<T>(6) * pi<T, policies::policy<policies::digits2<N> > >() | |
958 * pi<T, policies::policy<policies::digits2<N> > >()) | |
959 - (static_cast<T>(24) * pi<T, policies::policy<policies::digits2<N> > >()) + static_cast<T>(16) ) | |
960 / | |
961 ((pi<T, policies::policy<policies::digits2<N> > >() - static_cast<T>(4)) | |
962 * (pi<T, policies::policy<policies::digits2<N> > >() - static_cast<T>(4))) | |
963 ); | |
964 } | |
965 | |
966 }}}} // namespaces | |
967 | |
968 #endif // BOOST_MATH_CALCULATE_CONSTANTS_CONSTANTS_INCLUDED |