rational.hpp 13 KB

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  1. // (C) Copyright John Maddock 2006.
  2. // Use, modification and distribution are subject to the
  3. // Boost Software License, Version 1.0. (See accompanying file
  4. // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  5. #ifndef BOOST_MATH_TOOLS_RATIONAL_HPP
  6. #define BOOST_MATH_TOOLS_RATIONAL_HPP
  7. #ifdef _MSC_VER
  8. #pragma once
  9. #endif
  10. #include <boost/array.hpp>
  11. #include <boost/math/tools/config.hpp>
  12. #include <boost/mpl/int.hpp>
  13. #if BOOST_MATH_POLY_METHOD == 1
  14. # define BOOST_HEADER() <BOOST_JOIN(boost/math/tools/detail/polynomial_horner1_, BOOST_MATH_MAX_POLY_ORDER).hpp>
  15. # include BOOST_HEADER()
  16. # undef BOOST_HEADER
  17. #elif BOOST_MATH_POLY_METHOD == 2
  18. # define BOOST_HEADER() <BOOST_JOIN(boost/math/tools/detail/polynomial_horner2_, BOOST_MATH_MAX_POLY_ORDER).hpp>
  19. # include BOOST_HEADER()
  20. # undef BOOST_HEADER
  21. #elif BOOST_MATH_POLY_METHOD == 3
  22. # define BOOST_HEADER() <BOOST_JOIN(boost/math/tools/detail/polynomial_horner3_, BOOST_MATH_MAX_POLY_ORDER).hpp>
  23. # include BOOST_HEADER()
  24. # undef BOOST_HEADER
  25. #endif
  26. #if BOOST_MATH_RATIONAL_METHOD == 1
  27. # define BOOST_HEADER() <BOOST_JOIN(boost/math/tools/detail/rational_horner1_, BOOST_MATH_MAX_POLY_ORDER).hpp>
  28. # include BOOST_HEADER()
  29. # undef BOOST_HEADER
  30. #elif BOOST_MATH_RATIONAL_METHOD == 2
  31. # define BOOST_HEADER() <BOOST_JOIN(boost/math/tools/detail/rational_horner2_, BOOST_MATH_MAX_POLY_ORDER).hpp>
  32. # include BOOST_HEADER()
  33. # undef BOOST_HEADER
  34. #elif BOOST_MATH_RATIONAL_METHOD == 3
  35. # define BOOST_HEADER() <BOOST_JOIN(boost/math/tools/detail/rational_horner3_, BOOST_MATH_MAX_POLY_ORDER).hpp>
  36. # include BOOST_HEADER()
  37. # undef BOOST_HEADER
  38. #endif
  39. #if 0
  40. //
  41. // This just allows dependency trackers to find the headers
  42. // used in the above PP-magic.
  43. //
  44. #include <boost/math/tools/detail/polynomial_horner1_2.hpp>
  45. #include <boost/math/tools/detail/polynomial_horner1_3.hpp>
  46. #include <boost/math/tools/detail/polynomial_horner1_4.hpp>
  47. #include <boost/math/tools/detail/polynomial_horner1_5.hpp>
  48. #include <boost/math/tools/detail/polynomial_horner1_6.hpp>
  49. #include <boost/math/tools/detail/polynomial_horner1_7.hpp>
  50. #include <boost/math/tools/detail/polynomial_horner1_8.hpp>
  51. #include <boost/math/tools/detail/polynomial_horner1_9.hpp>
  52. #include <boost/math/tools/detail/polynomial_horner1_10.hpp>
  53. #include <boost/math/tools/detail/polynomial_horner1_11.hpp>
  54. #include <boost/math/tools/detail/polynomial_horner1_12.hpp>
  55. #include <boost/math/tools/detail/polynomial_horner1_13.hpp>
  56. #include <boost/math/tools/detail/polynomial_horner1_14.hpp>
  57. #include <boost/math/tools/detail/polynomial_horner1_15.hpp>
  58. #include <boost/math/tools/detail/polynomial_horner1_16.hpp>
  59. #include <boost/math/tools/detail/polynomial_horner1_17.hpp>
  60. #include <boost/math/tools/detail/polynomial_horner1_18.hpp>
  61. #include <boost/math/tools/detail/polynomial_horner1_19.hpp>
  62. #include <boost/math/tools/detail/polynomial_horner1_20.hpp>
  63. #include <boost/math/tools/detail/polynomial_horner2_2.hpp>
  64. #include <boost/math/tools/detail/polynomial_horner2_3.hpp>
  65. #include <boost/math/tools/detail/polynomial_horner2_4.hpp>
  66. #include <boost/math/tools/detail/polynomial_horner2_5.hpp>
  67. #include <boost/math/tools/detail/polynomial_horner2_6.hpp>
  68. #include <boost/math/tools/detail/polynomial_horner2_7.hpp>
  69. #include <boost/math/tools/detail/polynomial_horner2_8.hpp>
  70. #include <boost/math/tools/detail/polynomial_horner2_9.hpp>
  71. #include <boost/math/tools/detail/polynomial_horner2_10.hpp>
  72. #include <boost/math/tools/detail/polynomial_horner2_11.hpp>
  73. #include <boost/math/tools/detail/polynomial_horner2_12.hpp>
  74. #include <boost/math/tools/detail/polynomial_horner2_13.hpp>
  75. #include <boost/math/tools/detail/polynomial_horner2_14.hpp>
  76. #include <boost/math/tools/detail/polynomial_horner2_15.hpp>
  77. #include <boost/math/tools/detail/polynomial_horner2_16.hpp>
  78. #include <boost/math/tools/detail/polynomial_horner2_17.hpp>
  79. #include <boost/math/tools/detail/polynomial_horner2_18.hpp>
  80. #include <boost/math/tools/detail/polynomial_horner2_19.hpp>
  81. #include <boost/math/tools/detail/polynomial_horner2_20.hpp>
  82. #include <boost/math/tools/detail/polynomial_horner3_2.hpp>
  83. #include <boost/math/tools/detail/polynomial_horner3_3.hpp>
  84. #include <boost/math/tools/detail/polynomial_horner3_4.hpp>
  85. #include <boost/math/tools/detail/polynomial_horner3_5.hpp>
  86. #include <boost/math/tools/detail/polynomial_horner3_6.hpp>
  87. #include <boost/math/tools/detail/polynomial_horner3_7.hpp>
  88. #include <boost/math/tools/detail/polynomial_horner3_8.hpp>
  89. #include <boost/math/tools/detail/polynomial_horner3_9.hpp>
  90. #include <boost/math/tools/detail/polynomial_horner3_10.hpp>
  91. #include <boost/math/tools/detail/polynomial_horner3_11.hpp>
  92. #include <boost/math/tools/detail/polynomial_horner3_12.hpp>
  93. #include <boost/math/tools/detail/polynomial_horner3_13.hpp>
  94. #include <boost/math/tools/detail/polynomial_horner3_14.hpp>
  95. #include <boost/math/tools/detail/polynomial_horner3_15.hpp>
  96. #include <boost/math/tools/detail/polynomial_horner3_16.hpp>
  97. #include <boost/math/tools/detail/polynomial_horner3_17.hpp>
  98. #include <boost/math/tools/detail/polynomial_horner3_18.hpp>
  99. #include <boost/math/tools/detail/polynomial_horner3_19.hpp>
  100. #include <boost/math/tools/detail/polynomial_horner3_20.hpp>
  101. #include <boost/math/tools/detail/rational_horner1_2.hpp>
  102. #include <boost/math/tools/detail/rational_horner1_3.hpp>
  103. #include <boost/math/tools/detail/rational_horner1_4.hpp>
  104. #include <boost/math/tools/detail/rational_horner1_5.hpp>
  105. #include <boost/math/tools/detail/rational_horner1_6.hpp>
  106. #include <boost/math/tools/detail/rational_horner1_7.hpp>
  107. #include <boost/math/tools/detail/rational_horner1_8.hpp>
  108. #include <boost/math/tools/detail/rational_horner1_9.hpp>
  109. #include <boost/math/tools/detail/rational_horner1_10.hpp>
  110. #include <boost/math/tools/detail/rational_horner1_11.hpp>
  111. #include <boost/math/tools/detail/rational_horner1_12.hpp>
  112. #include <boost/math/tools/detail/rational_horner1_13.hpp>
  113. #include <boost/math/tools/detail/rational_horner1_14.hpp>
  114. #include <boost/math/tools/detail/rational_horner1_15.hpp>
  115. #include <boost/math/tools/detail/rational_horner1_16.hpp>
  116. #include <boost/math/tools/detail/rational_horner1_17.hpp>
  117. #include <boost/math/tools/detail/rational_horner1_18.hpp>
  118. #include <boost/math/tools/detail/rational_horner1_19.hpp>
  119. #include <boost/math/tools/detail/rational_horner1_20.hpp>
  120. #include <boost/math/tools/detail/rational_horner2_2.hpp>
  121. #include <boost/math/tools/detail/rational_horner2_3.hpp>
  122. #include <boost/math/tools/detail/rational_horner2_4.hpp>
  123. #include <boost/math/tools/detail/rational_horner2_5.hpp>
  124. #include <boost/math/tools/detail/rational_horner2_6.hpp>
  125. #include <boost/math/tools/detail/rational_horner2_7.hpp>
  126. #include <boost/math/tools/detail/rational_horner2_8.hpp>
  127. #include <boost/math/tools/detail/rational_horner2_9.hpp>
  128. #include <boost/math/tools/detail/rational_horner2_10.hpp>
  129. #include <boost/math/tools/detail/rational_horner2_11.hpp>
  130. #include <boost/math/tools/detail/rational_horner2_12.hpp>
  131. #include <boost/math/tools/detail/rational_horner2_13.hpp>
  132. #include <boost/math/tools/detail/rational_horner2_14.hpp>
  133. #include <boost/math/tools/detail/rational_horner2_15.hpp>
  134. #include <boost/math/tools/detail/rational_horner2_16.hpp>
  135. #include <boost/math/tools/detail/rational_horner2_17.hpp>
  136. #include <boost/math/tools/detail/rational_horner2_18.hpp>
  137. #include <boost/math/tools/detail/rational_horner2_19.hpp>
  138. #include <boost/math/tools/detail/rational_horner2_20.hpp>
  139. #include <boost/math/tools/detail/rational_horner3_2.hpp>
  140. #include <boost/math/tools/detail/rational_horner3_3.hpp>
  141. #include <boost/math/tools/detail/rational_horner3_4.hpp>
  142. #include <boost/math/tools/detail/rational_horner3_5.hpp>
  143. #include <boost/math/tools/detail/rational_horner3_6.hpp>
  144. #include <boost/math/tools/detail/rational_horner3_7.hpp>
  145. #include <boost/math/tools/detail/rational_horner3_8.hpp>
  146. #include <boost/math/tools/detail/rational_horner3_9.hpp>
  147. #include <boost/math/tools/detail/rational_horner3_10.hpp>
  148. #include <boost/math/tools/detail/rational_horner3_11.hpp>
  149. #include <boost/math/tools/detail/rational_horner3_12.hpp>
  150. #include <boost/math/tools/detail/rational_horner3_13.hpp>
  151. #include <boost/math/tools/detail/rational_horner3_14.hpp>
  152. #include <boost/math/tools/detail/rational_horner3_15.hpp>
  153. #include <boost/math/tools/detail/rational_horner3_16.hpp>
  154. #include <boost/math/tools/detail/rational_horner3_17.hpp>
  155. #include <boost/math/tools/detail/rational_horner3_18.hpp>
  156. #include <boost/math/tools/detail/rational_horner3_19.hpp>
  157. #include <boost/math/tools/detail/rational_horner3_20.hpp>
  158. #endif
  159. namespace boost{ namespace math{ namespace tools{
  160. //
  161. // Forward declaration to keep two phase lookup happy:
  162. //
  163. template <class T, class U>
  164. U evaluate_polynomial(const T* poly, U const& z, std::size_t count) BOOST_MATH_NOEXCEPT(U);
  165. namespace detail{
  166. template <class T, class V, class Tag>
  167. inline V evaluate_polynomial_c_imp(const T* a, const V& val, const Tag*) BOOST_MATH_NOEXCEPT(V)
  168. {
  169. return evaluate_polynomial(a, val, Tag::value);
  170. }
  171. } // namespace detail
  172. //
  173. // Polynomial evaluation with runtime size.
  174. // This requires a for-loop which may be more expensive than
  175. // the loop expanded versions above:
  176. //
  177. template <class T, class U>
  178. inline U evaluate_polynomial(const T* poly, U const& z, std::size_t count) BOOST_MATH_NOEXCEPT(U)
  179. {
  180. BOOST_ASSERT(count > 0);
  181. U sum = static_cast<U>(poly[count - 1]);
  182. for(int i = static_cast<int>(count) - 2; i >= 0; --i)
  183. {
  184. sum *= z;
  185. sum += static_cast<U>(poly[i]);
  186. }
  187. return sum;
  188. }
  189. //
  190. // Compile time sized polynomials, just inline forwarders to the
  191. // implementations above:
  192. //
  193. template <std::size_t N, class T, class V>
  194. inline V evaluate_polynomial(const T(&a)[N], const V& val) BOOST_MATH_NOEXCEPT(V)
  195. {
  196. typedef mpl::int_<N> tag_type;
  197. return detail::evaluate_polynomial_c_imp(static_cast<const T*>(a), val, static_cast<tag_type const*>(0));
  198. }
  199. template <std::size_t N, class T, class V>
  200. inline V evaluate_polynomial(const boost::array<T,N>& a, const V& val) BOOST_MATH_NOEXCEPT(V)
  201. {
  202. typedef mpl::int_<N> tag_type;
  203. return detail::evaluate_polynomial_c_imp(static_cast<const T*>(a.data()), val, static_cast<tag_type const*>(0));
  204. }
  205. //
  206. // Even polynomials are trivial: just square the argument!
  207. //
  208. template <class T, class U>
  209. inline U evaluate_even_polynomial(const T* poly, U z, std::size_t count) BOOST_MATH_NOEXCEPT(U)
  210. {
  211. return evaluate_polynomial(poly, U(z*z), count);
  212. }
  213. template <std::size_t N, class T, class V>
  214. inline V evaluate_even_polynomial(const T(&a)[N], const V& z) BOOST_MATH_NOEXCEPT(V)
  215. {
  216. return evaluate_polynomial(a, V(z*z));
  217. }
  218. template <std::size_t N, class T, class V>
  219. inline V evaluate_even_polynomial(const boost::array<T,N>& a, const V& z) BOOST_MATH_NOEXCEPT(V)
  220. {
  221. return evaluate_polynomial(a, V(z*z));
  222. }
  223. //
  224. // Odd polynomials come next:
  225. //
  226. template <class T, class U>
  227. inline U evaluate_odd_polynomial(const T* poly, U z, std::size_t count) BOOST_MATH_NOEXCEPT(U)
  228. {
  229. return poly[0] + z * evaluate_polynomial(poly+1, U(z*z), count-1);
  230. }
  231. template <std::size_t N, class T, class V>
  232. inline V evaluate_odd_polynomial(const T(&a)[N], const V& z) BOOST_MATH_NOEXCEPT(V)
  233. {
  234. typedef mpl::int_<N-1> tag_type;
  235. return a[0] + z * detail::evaluate_polynomial_c_imp(static_cast<const T*>(a) + 1, V(z*z), static_cast<tag_type const*>(0));
  236. }
  237. template <std::size_t N, class T, class V>
  238. inline V evaluate_odd_polynomial(const boost::array<T,N>& a, const V& z) BOOST_MATH_NOEXCEPT(V)
  239. {
  240. typedef mpl::int_<N-1> tag_type;
  241. return a[0] + z * detail::evaluate_polynomial_c_imp(static_cast<const T*>(a.data()) + 1, V(z*z), static_cast<tag_type const*>(0));
  242. }
  243. template <class T, class U, class V>
  244. V evaluate_rational(const T* num, const U* denom, const V& z_, std::size_t count) BOOST_MATH_NOEXCEPT(V);
  245. namespace detail{
  246. template <class T, class U, class V, class Tag>
  247. inline V evaluate_rational_c_imp(const T* num, const U* denom, const V& z, const Tag*) BOOST_MATH_NOEXCEPT(V)
  248. {
  249. return boost::math::tools::evaluate_rational(num, denom, z, Tag::value);
  250. }
  251. }
  252. //
  253. // Rational functions: numerator and denominator must be
  254. // equal in size. These always have a for-loop and so may be less
  255. // efficient than evaluating a pair of polynomials. However, there
  256. // are some tricks we can use to prevent overflow that might otherwise
  257. // occur in polynomial evaluation, if z is large. This is important
  258. // in our Lanczos code for example.
  259. //
  260. template <class T, class U, class V>
  261. V evaluate_rational(const T* num, const U* denom, const V& z_, std::size_t count) BOOST_MATH_NOEXCEPT(V)
  262. {
  263. V z(z_);
  264. V s1, s2;
  265. if(z <= 1)
  266. {
  267. s1 = static_cast<V>(num[count-1]);
  268. s2 = static_cast<V>(denom[count-1]);
  269. for(int i = (int)count - 2; i >= 0; --i)
  270. {
  271. s1 *= z;
  272. s2 *= z;
  273. s1 += num[i];
  274. s2 += denom[i];
  275. }
  276. }
  277. else
  278. {
  279. z = 1 / z;
  280. s1 = static_cast<V>(num[0]);
  281. s2 = static_cast<V>(denom[0]);
  282. for(unsigned i = 1; i < count; ++i)
  283. {
  284. s1 *= z;
  285. s2 *= z;
  286. s1 += num[i];
  287. s2 += denom[i];
  288. }
  289. }
  290. return s1 / s2;
  291. }
  292. template <std::size_t N, class T, class U, class V>
  293. inline V evaluate_rational(const T(&a)[N], const U(&b)[N], const V& z) BOOST_MATH_NOEXCEPT(V)
  294. {
  295. return detail::evaluate_rational_c_imp(a, b, z, static_cast<const mpl::int_<N>*>(0));
  296. }
  297. template <std::size_t N, class T, class U, class V>
  298. inline V evaluate_rational(const boost::array<T,N>& a, const boost::array<U,N>& b, const V& z) BOOST_MATH_NOEXCEPT(V)
  299. {
  300. return detail::evaluate_rational_c_imp(a.data(), b.data(), z, static_cast<mpl::int_<N>*>(0));
  301. }
  302. } // namespace tools
  303. } // namespace math
  304. } // namespace boost
  305. #endif // BOOST_MATH_TOOLS_RATIONAL_HPP