series_expansion.hpp 25 KB

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  1. // Boost.Geometry
  2. // Copyright (c) 2018 Adeel Ahmad, Islamabad, Pakistan.
  3. // Contributed and/or modified by Adeel Ahmad, as part of Google Summer of Code 2018 program.
  4. // This file was modified by Oracle on 2019.
  5. // Modifications copyright (c) 2019 Oracle and/or its affiliates.
  6. // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
  7. // Use, modification and distribution is subject to the Boost Software License,
  8. // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  9. // http://www.boost.org/LICENSE_1_0.txt)
  10. // This file is converted from GeographicLib, https://geographiclib.sourceforge.io
  11. // GeographicLib is originally written by Charles Karney.
  12. // Author: Charles Karney (2008-2017)
  13. // Last updated version of GeographicLib: 1.49
  14. // Original copyright notice:
  15. // Copyright (c) Charles Karney (2008-2017) <charles@karney.com> and licensed
  16. // under the MIT/X11 License. For more information, see
  17. // https://geographiclib.sourceforge.io
  18. #ifndef BOOST_GEOMETRY_UTIL_SERIES_EXPANSION_HPP
  19. #define BOOST_GEOMETRY_UTIL_SERIES_EXPANSION_HPP
  20. #include <boost/geometry/core/assert.hpp>
  21. #include <boost/geometry/util/math.hpp>
  22. namespace boost { namespace geometry { namespace series_expansion {
  23. /*
  24. Generate and evaluate the series expansion of the following integral
  25. I1 = integrate( sqrt(1+k2*sin(sigma1)^2), sigma1, 0, sigma )
  26. which is valid for k2 small. We substitute k2 = 4 * eps / (1 - eps)^2
  27. and expand (1 - eps) * I1 retaining terms up to order eps^maxpow
  28. in A1 and C1[l].
  29. The resulting series is of the form
  30. A1 * ( sigma + sum(C1[l] * sin(2*l*sigma), l, 1, maxpow) ).
  31. The scale factor A1-1 = mean value of (d/dsigma)I1 - 1
  32. The expansion above is performed in Maxima, a Computer Algebra System.
  33. The C++ code (that yields the function evaluate_A1 below) is
  34. generated by the following Maxima script:
  35. geometry/doc/other/maxima/geod.mac
  36. To replace each number x by CT(x) the following
  37. script can be used:
  38. sed -e 's/[0-9]\+/CT(&)/g; s/\[CT/\[/g; s/)\]/\]/g;
  39. s/case\sCT(/case /g; s/):/:/g; s/epsCT(2)/eps2/g;'
  40. */
  41. template <size_t SeriesOrder, typename CT>
  42. inline CT evaluate_A1(CT eps)
  43. {
  44. CT eps2 = math::sqr(eps);
  45. CT t;
  46. switch (SeriesOrder/2)
  47. {
  48. case 0:
  49. t = CT(0);
  50. break;
  51. case 1:
  52. t = eps2/CT(4);
  53. break;
  54. case 2:
  55. t = eps2*(eps2+CT(16))/CT(64);
  56. break;
  57. case 3:
  58. t = eps2*(eps2*(eps2+CT(4))+CT(64))/CT(256);
  59. break;
  60. case 4:
  61. t = eps2*(eps2*(eps2*(CT(25)*eps2+CT(64))+CT(256))+CT(4096))/CT(16384);
  62. break;
  63. }
  64. return (t + eps) / (CT(1) - eps);
  65. }
  66. /*
  67. Generate and evaluate the series expansion of the following integral
  68. I2 = integrate( 1/sqrt(1+k2*sin(sigma1)^2), sigma1, 0, sigma )
  69. which is valid for k2 small. We substitute k2 = 4 * eps / (1 - eps)^2
  70. and expand (1 - eps) * I2 retaining terms up to order eps^maxpow
  71. in A2 and C2[l].
  72. The resulting series is of the form
  73. A2 * ( sigma + sum(C2[l] * sin(2*l*sigma), l, 1, maxpow) )
  74. The scale factor A2-1 = mean value of (d/dsigma)2 - 1
  75. The expansion above is performed in Maxima, a Computer Algebra System.
  76. The C++ code (that yields the function evaluate_A2 below) is
  77. generated by the following Maxima script:
  78. geometry/doc/other/maxima/geod.mac
  79. */
  80. template <size_t SeriesOrder, typename CT>
  81. inline CT evaluate_A2(CT const& eps)
  82. {
  83. CT const eps2 = math::sqr(eps);
  84. CT t;
  85. switch (SeriesOrder/2)
  86. {
  87. case 0:
  88. t = CT(0);
  89. break;
  90. case 1:
  91. t = -CT(3)*eps2/CT(4);
  92. break;
  93. case 2:
  94. t = (-CT(7)*eps2-CT(48))*eps2/CT(64);
  95. break;
  96. case 3:
  97. t = eps2*((-CT(11)*eps2-CT(28))*eps2-CT(192))/CT(256);
  98. break;
  99. default:
  100. t = eps2*(eps2*((-CT(375)*eps2-CT(704))*eps2-CT(1792))-CT(12288))/CT(16384);
  101. break;
  102. }
  103. return (t - eps) / (CT(1) + eps);
  104. }
  105. /*
  106. Express
  107. I3 = integrate( (2-f)/(1+(1-f)*sqrt(1+k2*sin(sigma1)^2)), sigma1, 0, sigma )
  108. as a series
  109. A3 * ( sigma + sum(C3[l] * sin(2*l*sigma), l, 1, maxpow-1) )
  110. valid for f and k2 small. It is convenient to write k2 = 4 * eps / (1 -
  111. eps)^2 and f = 2*n/(1+n) and expand in eps and n. This procedure leads
  112. to a series where the coefficients of eps^j are terminating series in n.
  113. The scale factor A3 = mean value of (d/dsigma)I3
  114. The expansion above is performed in Maxima, a Computer Algebra System.
  115. The C++ code (that yields the function evaluate_coeffs_A3 below) is
  116. generated by the following Maxima script:
  117. geometry/doc/other/maxima/geod.mac
  118. */
  119. template <typename Coeffs, typename CT>
  120. inline void evaluate_coeffs_A3(Coeffs &c, CT const& n)
  121. {
  122. switch (int(Coeffs::static_size))
  123. {
  124. case 0:
  125. break;
  126. case 1:
  127. c[0] = CT(1);
  128. break;
  129. case 2:
  130. c[0] = CT(1);
  131. c[1] = -CT(1)/CT(2);
  132. break;
  133. case 3:
  134. c[0] = CT(1);
  135. c[1] = (n-CT(1))/CT(2);
  136. c[2] = -CT(1)/CT(4);
  137. break;
  138. case 4:
  139. c[0] = CT(1);
  140. c[1] = (n-CT(1))/CT(2);
  141. c[2] = (-n-CT(2))/CT(8);
  142. c[3] = -CT(1)/CT(16);
  143. break;
  144. case 5:
  145. c[0] = CT(1);
  146. c[1] = (n-CT(1))/CT(2);
  147. c[2] = (n*(CT(3)*n-CT(1))-CT(2))/CT(8);
  148. c[3] = (-CT(3)*n-CT(1))/CT(16);
  149. c[4] = -CT(3)/CT(64);
  150. break;
  151. case 6:
  152. c[0] = CT(1);
  153. c[1] = (n-CT(1))/CT(2);
  154. c[2] = (n*(CT(3)*n-CT(1))-CT(2))/CT(8);
  155. c[3] = ((-n-CT(3))*n-CT(1))/CT(16);
  156. c[4] = (-CT(2)*n-CT(3))/CT(64);
  157. c[5] = -CT(3)/CT(128);
  158. break;
  159. case 7:
  160. c[0] = CT(1);
  161. c[1] = (n-CT(1))/CT(2);
  162. c[2] = (n*(CT(3)*n-CT(1))-CT(2))/CT(8);
  163. c[3] = (n*(n*(CT(5)*n-CT(1))-CT(3))-CT(1))/CT(16);
  164. c[4] = ((-CT(10)*n-CT(2))*n-CT(3))/CT(64);
  165. c[5] = (-CT(5)*n-CT(3))/CT(128);
  166. c[6] = -CT(5)/CT(256);
  167. break;
  168. default:
  169. c[0] = CT(1);
  170. c[1] = (n-CT(1))/CT(2);
  171. c[2] = (n*(CT(3)*n-CT(1))-CT(2))/CT(8);
  172. c[3] = (n*(n*(CT(5)*n-CT(1))-CT(3))-CT(1))/CT(16);
  173. c[4] = (n*((-CT(5)*n-CT(20))*n-CT(4))-CT(6))/CT(128);
  174. c[5] = ((-CT(5)*n-CT(10))*n-CT(6))/CT(256);
  175. c[6] = (-CT(15)*n-CT(20))/CT(1024);
  176. c[7] = -CT(25)/CT(2048);
  177. break;
  178. }
  179. }
  180. /*
  181. The coefficients C1[l] in the Fourier expansion of B1.
  182. The expansion below is performed in Maxima, a Computer Algebra System.
  183. The C++ code (that yields the function evaluate_coeffs_C1 below) is
  184. generated by the following Maxima script:
  185. geometry/doc/other/maxima/geod.mac
  186. */
  187. template <typename Coeffs, typename CT>
  188. inline void evaluate_coeffs_C1(Coeffs &c, CT const& eps)
  189. {
  190. CT eps2 = math::sqr(eps);
  191. CT d = eps;
  192. switch (int(Coeffs::static_size) - 1)
  193. {
  194. case 0:
  195. break;
  196. case 1:
  197. c[1] = -d/CT(2);
  198. break;
  199. case 2:
  200. c[1] = -d/CT(2);
  201. d *= eps;
  202. c[2] = -d/CT(16);
  203. break;
  204. case 3:
  205. c[1] = d*(CT(3)*eps2-CT(8))/CT(16);
  206. d *= eps;
  207. c[2] = -d/CT(16);
  208. d *= eps;
  209. c[3] = -d/CT(48);
  210. break;
  211. case 4:
  212. c[1] = d*(CT(3)*eps2-CT(8))/CT(16);
  213. d *= eps;
  214. c[2] = d*(eps2-CT(2))/CT(32);
  215. d *= eps;
  216. c[3] = -d/CT(48);
  217. d *= eps;
  218. c[4] = -CT(5)*d/CT(512);
  219. break;
  220. case 5:
  221. c[1] = d*((CT(6)-eps2)*eps2-CT(16))/CT(32);
  222. d *= eps;
  223. c[2] = d*(eps2-CT(2))/CT(32);
  224. d *= eps;
  225. c[3] = d*(CT(9)*eps2-CT(16))/CT(768);
  226. d *= eps;
  227. c[4] = -CT(5)*d/CT(512);
  228. d *= eps;
  229. c[5] = -CT(7)*d/CT(1280);
  230. break;
  231. case 6:
  232. c[1] = d*((CT(6)-eps2)*eps2-CT(16))/CT(32);
  233. d *= eps;
  234. c[2] = d*((CT(64)-CT(9)*eps2)*eps2-CT(128))/CT(2048);
  235. d *= eps;
  236. c[3] = d*(CT(9)*eps2-CT(16))/CT(768);
  237. d *= eps;
  238. c[4] = d*(CT(3)*eps2-CT(5))/CT(512);
  239. d *= eps;
  240. c[5] = -CT(7)*d/CT(1280);
  241. d *= eps;
  242. c[6] = -CT(7)*d/CT(2048);
  243. break;
  244. case 7:
  245. c[1] = d*(eps2*(eps2*(CT(19)*eps2-CT(64))+CT(384))-CT(1024))/CT(2048);
  246. d *= eps;
  247. c[2] = d*((CT(64)-CT(9)*eps2)*eps2-CT(128))/CT(2048);
  248. d *= eps;
  249. c[3] = d*((CT(72)-CT(9)*eps2)*eps2-CT(128))/CT(6144);
  250. d *= eps;
  251. c[4] = d*(CT(3)*eps2-CT(5))/CT(512);
  252. d *= eps;
  253. c[5] = d*(CT(35)*eps2-CT(56))/CT(10240);
  254. d *= eps;
  255. c[6] = -CT(7)*d/CT(2048);
  256. d *= eps;
  257. c[7] = -CT(33)*d/CT(14336);
  258. break;
  259. default:
  260. c[1] = d*(eps2*(eps2*(CT(19)*eps2-CT(64))+CT(384))-CT(1024))/CT(2048);
  261. d *= eps;
  262. c[2] = d*(eps2*(eps2*(CT(7)*eps2-CT(18))+CT(128))-CT(256))/CT(4096);
  263. d *= eps;
  264. c[3] = d*((CT(72)-CT(9)*eps2)*eps2-CT(128))/CT(6144);
  265. d *= eps;
  266. c[4] = d*((CT(96)-CT(11)*eps2)*eps2-CT(160))/CT(16384);
  267. d *= eps;
  268. c[5] = d*(CT(35)*eps2-CT(56))/CT(10240);
  269. d *= eps;
  270. c[6] = d*(CT(9)*eps2-CT(14))/CT(4096);
  271. d *= eps;
  272. c[7] = -CT(33)*d/CT(14336);
  273. d *= eps;
  274. c[8] = -CT(429)*d/CT(262144);
  275. break;
  276. }
  277. }
  278. /*
  279. The coefficients C1p[l] in the Fourier expansion of B1p.
  280. The expansion below is performed in Maxima, a Computer Algebra System.
  281. The C++ code (that yields the function evaluate_coeffs_C1p below) is
  282. generated by the following Maxima script:
  283. geometry/doc/other/maxima/geod.mac
  284. */
  285. template <typename Coeffs, typename CT>
  286. inline void evaluate_coeffs_C1p(Coeffs& c, CT const& eps)
  287. {
  288. CT const eps2 = math::sqr(eps);
  289. CT d = eps;
  290. switch (int(Coeffs::static_size) - 1)
  291. {
  292. case 0:
  293. break;
  294. case 1:
  295. c[1] = d/CT(2);
  296. break;
  297. case 2:
  298. c[1] = d/CT(2);
  299. d *= eps;
  300. c[2] = CT(5)*d/CT(16);
  301. break;
  302. case 3:
  303. c[1] = d*(CT(16)-CT(9)*eps2)/CT(32);
  304. d *= eps;
  305. c[2] = CT(5)*d/CT(16);
  306. d *= eps;
  307. c[3] = CT(29)*d/CT(96);
  308. break;
  309. case 4:
  310. c[1] = d*(CT(16)-CT(9)*eps2)/CT(32);
  311. d *= eps;
  312. c[2] = d*(CT(30)-CT(37)*eps2)/CT(96);
  313. d *= eps;
  314. c[3] = CT(29)*d/CT(96);
  315. d *= eps;
  316. c[4] = CT(539)*d/CT(1536);
  317. break;
  318. case 5:
  319. c[1] = d*(eps2*(CT(205)*eps2-CT(432))+CT(768))/CT(1536);
  320. d *= eps;
  321. c[2] = d*(CT(30)-CT(37)*eps2)/CT(96);
  322. d *= eps;
  323. c[3] = d*(CT(116)-CT(225)*eps2)/CT(384);
  324. d *= eps;
  325. c[4] = CT(539)*d/CT(1536);
  326. d *= eps;
  327. c[5] = CT(3467)*d/CT(7680);
  328. break;
  329. case 6:
  330. c[1] = d*(eps2*(CT(205)*eps2-CT(432))+CT(768))/CT(1536);
  331. d *= eps;
  332. c[2] = d*(eps2*(CT(4005)*eps2-CT(4736))+CT(3840))/CT(12288);
  333. d *= eps;
  334. c[3] = d*(CT(116)-CT(225)*eps2)/CT(384);
  335. d *= eps;
  336. c[4] = d*(CT(2695)-CT(7173)*eps2)/CT(7680);
  337. d *= eps;
  338. c[5] = CT(3467)*d/CT(7680);
  339. d *= eps;
  340. c[6] = CT(38081)*d/CT(61440);
  341. break;
  342. case 7:
  343. c[1] = d*(eps2*((CT(9840)-CT(4879)*eps2)*eps2-CT(20736))+CT(36864))/CT(73728);
  344. d *= eps;
  345. c[2] = d*(eps2*(CT(4005)*eps2-CT(4736))+CT(3840))/CT(12288);
  346. d *= eps;
  347. c[3] = d*(eps2*(CT(8703)*eps2-CT(7200))+CT(3712))/CT(12288);
  348. d *= eps;
  349. c[4] = d*(CT(2695)-CT(7173)*eps2)/CT(7680);
  350. d *= eps;
  351. c[5] = d*(CT(41604)-CT(141115)*eps2)/CT(92160);
  352. d *= eps;
  353. c[6] = CT(38081)*d/CT(61440);
  354. d *= eps;
  355. c[7] = CT(459485)*d/CT(516096);
  356. break;
  357. default:
  358. c[1] = d*(eps2*((CT(9840)-CT(4879)*eps2)*eps2-CT(20736))+CT(36864))/CT(73728);
  359. d *= eps;
  360. c[2] = d*(eps2*((CT(120150)-CT(86171)*eps2)*eps2-CT(142080))+CT(115200))/CT(368640);
  361. d *= eps;
  362. c[3] = d*(eps2*(CT(8703)*eps2-CT(7200))+CT(3712))/CT(12288);
  363. d *= eps;
  364. c[4] = d*(eps2*(CT(1082857)*eps2-CT(688608))+CT(258720))/CT(737280);
  365. d *= eps;
  366. c[5] = d*(CT(41604)-CT(141115)*eps2)/CT(92160);
  367. d *= eps;
  368. c[6] = d*(CT(533134)-CT(2200311)*eps2)/CT(860160);
  369. d *= eps;
  370. c[7] = CT(459485)*d/CT(516096);
  371. d *= eps;
  372. c[8] = CT(109167851)*d/CT(82575360);
  373. break;
  374. }
  375. }
  376. /*
  377. The coefficients C2[l] in the Fourier expansion of B2.
  378. The expansion below is performed in Maxima, a Computer Algebra System.
  379. The C++ code (that yields the function evaluate_coeffs_C2 below) is
  380. generated by the following Maxima script:
  381. geometry/doc/other/maxima/geod.mac
  382. */
  383. template <typename Coeffs, typename CT>
  384. inline void evaluate_coeffs_C2(Coeffs& c, CT const& eps)
  385. {
  386. CT const eps2 = math::sqr(eps);
  387. CT d = eps;
  388. switch (int(Coeffs::static_size) - 1)
  389. {
  390. case 0:
  391. break;
  392. case 1:
  393. c[1] = d/CT(2);
  394. break;
  395. case 2:
  396. c[1] = d/CT(2);
  397. d *= eps;
  398. c[2] = CT(3)*d/CT(16);
  399. break;
  400. case 3:
  401. c[1] = d*(eps2+CT(8))/CT(16);
  402. d *= eps;
  403. c[2] = CT(3)*d/CT(16);
  404. d *= eps;
  405. c[3] = CT(5)*d/CT(48);
  406. break;
  407. case 4:
  408. c[1] = d*(eps2+CT(8))/CT(16);
  409. d *= eps;
  410. c[2] = d*(eps2+CT(6))/CT(32);
  411. d *= eps;
  412. c[3] = CT(5)*d/CT(48);
  413. d *= eps;
  414. c[4] = CT(35)*d/CT(512);
  415. break;
  416. case 5:
  417. c[1] = d*(eps2*(eps2+CT(2))+CT(16))/CT(32);
  418. d *= eps;
  419. c[2] = d*(eps2+CT(6))/CT(32);
  420. d *= eps;
  421. c[3] = d*(CT(15)*eps2+CT(80))/CT(768);
  422. d *= eps;
  423. c[4] = CT(35)*d/CT(512);
  424. d *= eps;
  425. c[5] = CT(63)*d/CT(1280);
  426. break;
  427. case 6:
  428. c[1] = d*(eps2*(eps2+CT(2))+CT(16))/CT(32);
  429. d *= eps;
  430. c[2] = d*(eps2*(CT(35)*eps2+CT(64))+CT(384))/CT(2048);
  431. d *= eps;
  432. c[3] = d*(CT(15)*eps2+CT(80))/CT(768);
  433. d *= eps;
  434. c[4] = d*(CT(7)*eps2+CT(35))/CT(512);
  435. d *= eps;
  436. c[5] = CT(63)*d/CT(1280);
  437. d *= eps;
  438. c[6] = CT(77)*d/CT(2048);
  439. break;
  440. case 7:
  441. c[1] = d*(eps2*(eps2*(CT(41)*eps2+CT(64))+CT(128))+CT(1024))/CT(2048);
  442. d *= eps;
  443. c[2] = d*(eps2*(CT(35)*eps2+CT(64))+CT(384))/CT(2048);
  444. d *= eps;
  445. c[3] = d*(eps2*(CT(69)*eps2+CT(120))+CT(640))/CT(6144);
  446. d *= eps;
  447. c[4] = d*(CT(7)*eps2+CT(35))/CT(512);
  448. d *= eps;
  449. c[5] = d*(CT(105)*eps2+CT(504))/CT(10240);
  450. d *= eps;
  451. c[6] = CT(77)*d/CT(2048);
  452. d *= eps;
  453. c[7] = CT(429)*d/CT(14336);
  454. break;
  455. default:
  456. c[1] = d*(eps2*(eps2*(CT(41)*eps2+CT(64))+CT(128))+CT(1024))/CT(2048);
  457. d *= eps;
  458. c[2] = d*(eps2*(eps2*(CT(47)*eps2+CT(70))+CT(128))+CT(768))/CT(4096);
  459. d *= eps;
  460. c[3] = d*(eps2*(CT(69)*eps2+CT(120))+CT(640))/CT(6144);
  461. d *= eps;
  462. c[4] = d*(eps2*(CT(133)*eps2+CT(224))+CT(1120))/CT(16384);
  463. d *= eps;
  464. c[5] = d*(CT(105)*eps2+CT(504))/CT(10240);
  465. d *= eps;
  466. c[6] = d*(CT(33)*eps2+CT(154))/CT(4096);
  467. d *= eps;
  468. c[7] = CT(429)*d/CT(14336);
  469. d *= eps;
  470. c[8] = CT(6435)*d/CT(262144);
  471. break;
  472. }
  473. }
  474. /*
  475. The coefficients C3[l] in the Fourier expansion of B3.
  476. The expansion below is performed in Maxima, a Computer Algebra System.
  477. The C++ code (that yields the function evaluate_coeffs_C3 below) is
  478. generated by the following Maxima script:
  479. geometry/doc/other/maxima/geod.mac
  480. */
  481. template <size_t SeriesOrder, typename Coeffs, typename CT>
  482. inline void evaluate_coeffs_C3x(Coeffs &c, CT const& n) {
  483. BOOST_GEOMETRY_ASSERT((Coeffs::static_size == (SeriesOrder * (SeriesOrder - 1)) / 2));
  484. CT const n2 = math::sqr(n);
  485. switch (SeriesOrder)
  486. {
  487. case 0:
  488. break;
  489. case 1:
  490. break;
  491. case 2:
  492. c[0] = (CT(1)-n)/CT(4);
  493. break;
  494. case 3:
  495. c[0] = (CT(1)-n)/CT(4);
  496. c[1] = (CT(1)-n2)/CT(8);
  497. c[2] = ((n-CT(3))*n+CT(2))/CT(32);
  498. break;
  499. case 4:
  500. c[0] = (CT(1)-n)/CT(4);
  501. c[1] = (CT(1)-n2)/CT(8);
  502. c[2] = (n*((-CT(5)*n-CT(1))*n+CT(3))+CT(3))/CT(64);
  503. c[3] = ((n-CT(3))*n+CT(2))/CT(32);
  504. c[4] = (n*(n*(CT(2)*n-CT(3))-CT(2))+CT(3))/CT(64);
  505. c[5] = (n*((CT(5)-n)*n-CT(9))+CT(5))/CT(192);
  506. break;
  507. case 5:
  508. c[0] = (CT(1)-n)/CT(4);
  509. c[1] = (CT(1)-n2)/CT(8);
  510. c[2] = (n*((-CT(5)*n-CT(1))*n+CT(3))+CT(3))/CT(64);
  511. c[3] = (n*((CT(2)-CT(2)*n)*n+CT(2))+CT(5))/CT(128);
  512. c[4] = ((n-CT(3))*n+CT(2))/CT(32);
  513. c[5] = (n*(n*(CT(2)*n-CT(3))-CT(2))+CT(3))/CT(64);
  514. c[6] = (n*((-CT(6)*n-CT(9))*n+CT(2))+CT(6))/CT(256);
  515. c[7] = (n*((CT(5)-n)*n-CT(9))+CT(5))/CT(192);
  516. c[8] = (n*(n*(CT(10)*n-CT(6))-CT(10))+CT(9))/CT(384);
  517. c[9] = (n*((CT(20)-CT(7)*n)*n-CT(28))+CT(14))/CT(1024);
  518. break;
  519. case 6:
  520. c[0] = (CT(1)-n)/CT(4);
  521. c[1] = (CT(1)-n2)/CT(8);
  522. c[2] = (n*((-CT(5)*n-CT(1))*n+CT(3))+CT(3))/CT(64);
  523. c[3] = (n*((CT(2)-CT(2)*n)*n+CT(2))+CT(5))/CT(128);
  524. c[4] = (n*(CT(3)*n+CT(11))+CT(12))/CT(512);
  525. c[5] = ((n-CT(3))*n+CT(2))/CT(32);
  526. c[6] = (n*(n*(CT(2)*n-CT(3))-CT(2))+CT(3))/CT(64);
  527. c[7] = (n*((-CT(6)*n-CT(9))*n+CT(2))+CT(6))/CT(256);
  528. c[8] = ((CT(1)-CT(2)*n)*n+CT(5))/CT(256);
  529. c[9] = (n*((CT(5)-n)*n-CT(9))+CT(5))/CT(192);
  530. c[10] = (n*(n*(CT(10)*n-CT(6))-CT(10))+CT(9))/CT(384);
  531. c[11] = ((-CT(77)*n-CT(8))*n+CT(42))/CT(3072);
  532. c[12] = (n*((CT(20)-CT(7)*n)*n-CT(28))+CT(14))/CT(1024);
  533. c[13] = ((-CT(7)*n-CT(40))*n+CT(28))/CT(2048);
  534. c[14] = (n*(CT(75)*n-CT(90))+CT(42))/CT(5120);
  535. break;
  536. case 7:
  537. c[0] = (CT(1)-n)/CT(4);
  538. c[1] = (CT(1)-n2)/CT(8);
  539. c[2] = (n*((-CT(5)*n-CT(1))*n+CT(3))+CT(3))/CT(64);
  540. c[3] = (n*((CT(2)-CT(2)*n)*n+CT(2))+CT(5))/CT(128);
  541. c[4] = (n*(CT(3)*n+CT(11))+CT(12))/CT(512);
  542. c[5] = (CT(10)*n+CT(21))/CT(1024);
  543. c[6] = ((n-CT(3))*n+CT(2))/CT(32);
  544. c[7] = (n*(n*(CT(2)*n-CT(3))-CT(2))+CT(3))/CT(64);
  545. c[8] = (n*((-CT(6)*n-CT(9))*n+CT(2))+CT(6))/CT(256);
  546. c[9] = ((CT(1)-CT(2)*n)*n+CT(5))/CT(256);
  547. c[10] = (CT(69)*n+CT(108))/CT(8192);
  548. c[11] = (n*((CT(5)-n)*n-CT(9))+CT(5))/CT(192);
  549. c[12] = (n*(n*(CT(10)*n-CT(6))-CT(10))+CT(9))/CT(384);
  550. c[13] = ((-CT(77)*n-CT(8))*n+CT(42))/CT(3072);
  551. c[14] = (CT(12)-n)/CT(1024);
  552. c[15] = (n*((CT(20)-CT(7)*n)*n-CT(28))+CT(14))/CT(1024);
  553. c[16] = ((-CT(7)*n-CT(40))*n+CT(28))/CT(2048);
  554. c[17] = (CT(72)-CT(43)*n)/CT(8192);
  555. c[18] = (n*(CT(75)*n-CT(90))+CT(42))/CT(5120);
  556. c[19] = (CT(9)-CT(15)*n)/CT(1024);
  557. c[20] = (CT(44)-CT(99)*n)/CT(8192);
  558. break;
  559. default:
  560. c[0] = (CT(1)-n)/CT(4);
  561. c[1] = (CT(1)-n2)/CT(8);
  562. c[2] = (n*((-CT(5)*n-CT(1))*n+CT(3))+CT(3))/CT(64);
  563. c[3] = (n*((CT(2)-CT(2)*n)*n+CT(2))+CT(5))/CT(128);
  564. c[4] = (n*(CT(3)*n+CT(11))+CT(12))/CT(512);
  565. c[5] = (CT(10)*n+CT(21))/CT(1024);
  566. c[6] = CT(243)/CT(16384);
  567. c[7] = ((n-CT(3))*n+CT(2))/CT(32);
  568. c[8] = (n*(n*(CT(2)*n-CT(3))-CT(2))+CT(3))/CT(64);
  569. c[9] = (n*((-CT(6)*n-CT(9))*n+CT(2))+CT(6))/CT(256);
  570. c[10] = ((CT(1)-CT(2)*n)*n+CT(5))/CT(256);
  571. c[11] = (CT(69)*n+CT(108))/CT(8192);
  572. c[12] = CT(187)/CT(16384);
  573. c[13] = (n*((CT(5)-n)*n-CT(9))+CT(5))/CT(192);
  574. c[14] = (n*(n*(CT(10)*n-CT(6))-CT(10))+CT(9))/CT(384);
  575. c[15] = ((-CT(77)*n-CT(8))*n+CT(42))/CT(3072);
  576. c[16] = (CT(12)-n)/CT(1024);
  577. c[17] = CT(139)/CT(16384);
  578. c[18] = (n*((CT(20)-CT(7)*n)*n-CT(28))+CT(14))/CT(1024);
  579. c[19] = ((-CT(7)*n-CT(40))*n+CT(28))/CT(2048);
  580. c[20] = (CT(72)-CT(43)*n)/CT(8192);
  581. c[21] = CT(127)/CT(16384);
  582. c[22] = (n*(CT(75)*n-CT(90))+CT(42))/CT(5120);
  583. c[23] = (CT(9)-CT(15)*n)/CT(1024);
  584. c[24] = CT(99)/CT(16384);
  585. c[25] = (CT(44)-CT(99)*n)/CT(8192);
  586. c[26] = CT(99)/CT(16384);
  587. c[27] = CT(429)/CT(114688);
  588. break;
  589. }
  590. }
  591. /*
  592. \brief Given the set of coefficients coeffs2[] evaluate on
  593. C3 and return the set of coefficients coeffs1[].
  594. Elements coeffs1[1] through coeffs1[SeriesOrder - 1] are set.
  595. */
  596. template <typename Coeffs1, typename Coeffs2, typename CT>
  597. inline void evaluate_coeffs_C3(Coeffs1 &coeffs1, Coeffs2 &coeffs2, CT const& eps)
  598. {
  599. CT mult = 1;
  600. size_t offset = 0;
  601. // i is the index of C3[i].
  602. for (size_t i = 1; i < Coeffs1::static_size; ++i)
  603. {
  604. // Order of polynomial in eps.
  605. size_t m = Coeffs1::static_size - i;
  606. mult *= eps;
  607. coeffs1[i] = mult * math::horner_evaluate(eps, coeffs2.begin() + offset,
  608. coeffs2.begin() + offset + m);
  609. offset += m;
  610. }
  611. // Post condition: offset == coeffs_C3_size
  612. }
  613. /*
  614. \brief Evaluate the following:
  615. y = sum(c[i] * sin(2*i * x), i, 1, n)
  616. using Clenshaw summation.
  617. */
  618. template <typename CT, typename Coeffs>
  619. inline CT sin_cos_series(CT const& sinx, CT const& cosx, Coeffs const& coeffs)
  620. {
  621. size_t n = Coeffs::static_size - 1;
  622. size_t index = 0;
  623. // Point to one beyond last element.
  624. index += (n + 1);
  625. CT ar = 2 * (cosx - sinx) * (cosx + sinx);
  626. // If n is odd, get the last element.
  627. CT k0 = n & 1 ? coeffs[--index] : 0;
  628. CT k1 = 0;
  629. // Make n even.
  630. n /= 2;
  631. while (n--) {
  632. // Unroll loop x 2, so accumulators return to their original role.
  633. k1 = ar * k0 - k1 + coeffs[--index];
  634. k0 = ar * k1 - k0 + coeffs[--index];
  635. }
  636. return 2 * sinx * cosx * k0;
  637. }
  638. /*
  639. The coefficient containers for the series expansions.
  640. These structs allow the caller to only know the series order.
  641. */
  642. template <size_t SeriesOrder, typename CT>
  643. struct coeffs_C1 : boost::array<CT, SeriesOrder + 1>
  644. {
  645. coeffs_C1(CT const& epsilon)
  646. {
  647. evaluate_coeffs_C1(*this, epsilon);
  648. }
  649. };
  650. template <size_t SeriesOrder, typename CT>
  651. struct coeffs_C1p : boost::array<CT, SeriesOrder + 1>
  652. {
  653. coeffs_C1p(CT const& epsilon)
  654. {
  655. evaluate_coeffs_C1p(*this, epsilon);
  656. }
  657. };
  658. template <size_t SeriesOrder, typename CT>
  659. struct coeffs_C2 : boost::array<CT, SeriesOrder + 1>
  660. {
  661. coeffs_C2(CT const& epsilon)
  662. {
  663. evaluate_coeffs_C2(*this, epsilon);
  664. }
  665. };
  666. template <size_t SeriesOrder, typename CT>
  667. struct coeffs_C3x : boost::array<CT, (SeriesOrder * (SeriesOrder - 1)) / 2>
  668. {
  669. coeffs_C3x(CT const& n)
  670. {
  671. evaluate_coeffs_C3x<SeriesOrder>(*this, n);
  672. }
  673. };
  674. template <size_t SeriesOrder, typename CT>
  675. struct coeffs_C3 : boost::array<CT, SeriesOrder>
  676. {
  677. coeffs_C3(CT const& n, CT const& epsilon)
  678. {
  679. coeffs_C3x<SeriesOrder, CT> coeffs_C3x(n);
  680. evaluate_coeffs_C3(*this, coeffs_C3x, epsilon);
  681. }
  682. };
  683. template <size_t SeriesOrder, typename CT>
  684. struct coeffs_A3 : boost::array<CT, SeriesOrder>
  685. {
  686. coeffs_A3(CT const& n)
  687. {
  688. evaluate_coeffs_A3(*this, n);
  689. }
  690. };
  691. }}} // namespace boost::geometry::series_expansion
  692. #endif // BOOST_GEOMETRY_UTIL_SERIES_EXPANSION_HPP