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  1. #include "GMath.h"
  2. GVector3::GVector3(float x, float y, float z)
  3. {
  4. v[0] = x;
  5. v[1] = y;
  6. v[2] = z;
  7. }
  8. GVector3::GVector3(const GVector3 & copy)
  9. {
  10. v[0] = copy.v[0];
  11. v[1] = copy.v[1];
  12. v[2] = copy.v[2];
  13. }
  14. GVector3 & GVector3::operator=(const GVector3 & rhs)
  15. {
  16. v[0] = rhs.v[0];
  17. v[1] = rhs.v[1];
  18. v[2] = rhs.v[2];
  19. return *this;
  20. }
  21. GVector3 GVector3::operator+(const GVector3 & rhs) const
  22. {
  23. GVector3 ret;
  24. ret.v[0] = v[0] + rhs.v[0];
  25. ret.v[1] = v[1] + rhs.v[1];
  26. ret.v[2] = v[2] + rhs.v[2];
  27. return ret;
  28. }
  29. GVector3 GVector3::operator-(const GVector3 & rhs) const
  30. {
  31. GVector3 ret;
  32. ret.v[0] = v[0] - rhs.v[0];
  33. ret.v[1] = v[1] - rhs.v[1];
  34. ret.v[2] = v[2] - rhs.v[2];
  35. return ret;
  36. }
  37. GVector3 operator*(const GVector3 & lhs, const float & k)
  38. {
  39. GVector3 ret;
  40. ret.v[0] = lhs.v[0] * k;
  41. ret.v[1] = lhs.v[1] * k;
  42. ret.v[2] = lhs.v[2] * k;
  43. return ret;
  44. }
  45. GVector3 operator*(const float & k, const GVector3& rhs)
  46. {
  47. GVector3 ret;
  48. ret.v[0] = rhs.v[0] * k;
  49. ret.v[1] = rhs.v[1] * k;
  50. ret.v[2] = rhs.v[2] * k;
  51. return ret;
  52. }
  53. GVector3 operator/(const GVector3 & lhs, const float & k)
  54. {
  55. GVector3 ret;
  56. assert(k != 0);
  57. ret.v[0] = lhs.v[0] / k;
  58. ret.v[1] = lhs.v[1] / k;
  59. ret.v[2] = lhs.v[2] / k;
  60. return ret;
  61. }
  62. float norm(const GVector3 & v)
  63. {
  64. return SQRT(v.v[0] * v.v[0] + v.v[1] * v.v[1] + v.v[2] * v.v[2]);
  65. }
  66. GVector3 & GVector3::normalize()
  67. {
  68. float len = norm(*this);
  69. if (len > PRECISION) {
  70. v[0] /= len;
  71. v[1] /= len;
  72. v[2] /= len;
  73. }
  74. return *this;
  75. }
  76. float GVector3::operator*(const GVector3 & rhs) const
  77. {
  78. float ret;
  79. ret = v[0] * rhs.v[0] + v[1] * rhs.v[1] +v[2] * rhs.v[2];
  80. return ret;
  81. }
  82. GVector3 proj(const GVector3 & p, const GVector3 & q)
  83. {
  84. return (p*q) / SQR(norm(q)) * q;
  85. }
  86. GVector3 perp(const GVector3 & p, const GVector3 & q)
  87. {
  88. return p - proj(p,q);
  89. }
  90. GVector3 GVector3::operator^(const GVector3 & rhs) const
  91. {
  92. GVector3 ret;
  93. ret.v[0] = v[1] * rhs.v[2] - v[2] * rhs.v[1];
  94. ret.v[1] = v[2] * rhs.v[0] - v[0] * rhs.v[2];
  95. ret.v[2] = v[0] * rhs.v[1] - v[1] * rhs.v[0];
  96. return ret;
  97. }
  98. GVector3 & GVector3::Set(const float & x, const float & y, const float & z)
  99. {
  100. v[0] = x;
  101. v[1] = y;
  102. v[2] = z;
  103. return *this;
  104. }
  105. float distance(const GVector3 & v, const GVector3 u)
  106. {
  107. float ret = 0.0;
  108. float a = v.v[0] - u.v[0];
  109. float b = v.v[1] - u.v[1];
  110. float c = v.v[2] - u.v[2];
  111. ret = SQRT(SQR(a) + SQR(b) + SQR(c));
  112. return ret;
  113. }
  114. GVector3 & GVector3::operator+=(const GVector3 & rhs)
  115. {
  116. v[0] += rhs.v[0];
  117. v[1] += rhs.v[1];
  118. v[2] += rhs.v[2];
  119. return *this;
  120. }
  121. GVector3 & GVector3::operator-=(const GVector3 & rhs)
  122. {
  123. v[0] -= rhs.v[0];
  124. v[1] -= rhs.v[1];
  125. v[2] -= rhs.v[2];
  126. return *this;
  127. }
  128. ostream & operator<<(ostream & os, const GVector3 & v)
  129. {
  130. os << "[" << setw(2) << v.v[0] << ", " << setw(2) << v.v[1] << ", " << setw(2) << v.v[2] << "]";
  131. return os;
  132. }
  133. GVector3 & GVector3::operator*=(const float & k)
  134. {
  135. v[0] *= k;
  136. v[1] *= k;
  137. v[2] *= k;
  138. return *this;
  139. }
  140. GVector3 & GVector3::operator/=(const float & k)
  141. {
  142. v[0] /= k;
  143. v[1] /= k;
  144. v[2] /= k;
  145. return *this;
  146. }
  147. GVector3 & GVector3::operator^=(const GVector3 & rhs)
  148. {
  149. v[0] = v[1] * rhs.v[2] - v[2] * rhs.v[1];
  150. v[1] = v[2] * rhs.v[0] - v[0] * rhs.v[2];
  151. v[2] = v[0] * rhs.v[1] - v[1] * rhs.v[0];
  152. return *this;
  153. }
  154. bool GVector3::operator==(const GVector3 rhs) const
  155. {
  156. return !((*this) != rhs);
  157. }
  158. bool GVector3::operator!=(const GVector3 rhs) const
  159. {
  160. return (!EQ(v[0], rhs.v[0], PRECISION) || !EQ(v[1], rhs.v[1], PRECISION) || !EQ(v[2], rhs.v[2], PRECISION));
  161. }
  162. GVector3 GVector3::operator+() const
  163. {
  164. return *this;
  165. }
  166. GVector3 GVector3::operator-() const
  167. {
  168. return *this * -1;
  169. }
  170. float & GVector3::operator[](const int & idx)
  171. {
  172. return v[idx];
  173. }
  174. const float GVector3::operator[](const int & idx) const
  175. {
  176. return v[idx];
  177. }
  178. //----GVector----//
  179. GVector::GVector(int dim)
  180. {
  181. n = dim;
  182. v = new float[n];
  183. ARR_ZERO(v, n);
  184. }
  185. GVector::GVector(int dim, double x, ...)
  186. {
  187. n = dim;
  188. v = new float[n];
  189. va_list ap;
  190. va_start(ap, dim);
  191. for (int i = 0; i < n; i++) {
  192. v[i] = (float)va_arg(ap, double);
  193. }
  194. va_end(ap);
  195. }
  196. GVector::GVector(const GVector3 & copy)
  197. {
  198. n = 3;
  199. v = new float[3];
  200. v[0] = copy[0];
  201. v[1] = copy[1];
  202. v[2] = copy[2];
  203. }
  204. GVector::GVector(const GVector & copy)
  205. {
  206. n = copy.n;
  207. v = new float[n];
  208. memcpy(v, copy.v, n * sizeof(float));
  209. }
  210. GVector::~GVector()
  211. {
  212. if (v) {
  213. delete[] v;
  214. }
  215. v = NULL;
  216. }
  217. GVector & GVector::Set(double x, ...)
  218. {
  219. v[0] = (float)x;
  220. va_list ap;
  221. va_start(ap, x);
  222. for (int i = 1; i < n; i++) {
  223. v[i] = (float)va_arg(ap, double);
  224. }
  225. va_end(ap);
  226. return *this;
  227. }
  228. GVector & GVector::Set(float * p)
  229. {
  230. memcpy(v, p, sizeof(float) * n);
  231. return *this;
  232. }
  233. GVector & GVector::operator=(const GVector & rhs)
  234. {
  235. if (v) {
  236. delete[] v;
  237. }
  238. n = rhs.n;
  239. v = new float[n];
  240. memcpy(v, rhs.v, n * sizeof(float));
  241. return *this;
  242. }
  243. GVector & GVector::operator+=(const GVector & rhs)
  244. {
  245. assert(n = rhs.n);
  246. for (int i = 0; i < n; i++) {
  247. v[i] += rhs.v[i];
  248. }
  249. return *this;
  250. }
  251. GVector & GVector::operator-=(const GVector & rhs)
  252. {
  253. assert(n = rhs.n);
  254. for (int i = 0; i < n; i++) {
  255. v[i] -= rhs.v[i];
  256. }
  257. return *this;
  258. }
  259. GVector & GVector::operator+=(const float & k)
  260. {
  261. for (int i = 0; i < n; i++) {
  262. v[i] += k;
  263. }
  264. return *this;
  265. }
  266. GVector & GVector::operator-=(const float & k)
  267. {
  268. for (int i = 0; i < n; i++) {
  269. v[i] -= k;
  270. }
  271. return *this;
  272. }
  273. GVector & GVector::operator*=(const float & k)
  274. {
  275. for (int i = 0; i < n; i++) {
  276. v[i] *= k;
  277. }
  278. return *this;
  279. }
  280. GVector & GVector::operator/=(const float & k)
  281. {
  282. for (int i = 0; i < n; i++) {
  283. v[i] /= k;
  284. }
  285. return *this;
  286. }
  287. bool GVector::operator==(const GVector & rhs) const
  288. {
  289. return ((*this) == rhs);
  290. }
  291. bool GVector::operator!=(const GVector & rhs) const
  292. {
  293. assert(n == rhs.n);
  294. for (int i = 0; i < n; i++) {
  295. if (!EQ(v[i], rhs.v[i], PRECISION)) {
  296. return true;
  297. }
  298. }
  299. return false;
  300. }
  301. GVector GVector::operator+() const
  302. {
  303. return *this;
  304. }
  305. GVector GVector::operator-() const
  306. {
  307. return *this * -1;
  308. }
  309. GVector GVector::operator+(const GVector & rhs) const
  310. {
  311. assert(n == rhs.n);
  312. GVector ret = GVector(n);
  313. for (int i = 0; i < n; i++) {
  314. ret.v[i] = v[i] + rhs.v[i];
  315. }
  316. return ret;
  317. }
  318. GVector GVector::operator-(const GVector & rhs) const
  319. {
  320. assert(n == rhs.n);
  321. GVector ret = GVector(n);
  322. for (int i = 0; i < n; i++) {
  323. ret.v[i] = v[i] - rhs.v[i];
  324. }
  325. return ret;
  326. }
  327. float GVector::operator*(const GVector & rhs) const
  328. {
  329. assert(n == rhs.n);
  330. float ret = 0;
  331. for (int i = 0; i < n; i++) {
  332. ret += v[i] * rhs.v[i];
  333. }
  334. return ret;
  335. }
  336. GVector GVector::operator/(const float & k) const
  337. {
  338. GVector ret = GVector(n);
  339. for (int i = 0; i < n; i++) {
  340. ret.v[i] = v[i]/k;
  341. }
  342. return ret;
  343. }
  344. float & GVector::operator[](const int & idx)
  345. {
  346. assert(idx >= 0 && idx <= n);
  347. return v[idx];
  348. }
  349. const float & GVector::operator[](const int & idx) const
  350. {
  351. assert(idx >= 0 && idx <= n);
  352. return v[idx];
  353. }
  354. GVector & GVector::Nornalize()
  355. {
  356. float m = norm(*this);
  357. for (int i = 0; i < n; i++) {
  358. v[i] /= m;
  359. }
  360. return *this;
  361. }
  362. int GVector::GetDim() const
  363. {
  364. return n;
  365. }
  366. GVector operator*(const float & k, const GVector & rhs)
  367. {
  368. GVector ret(rhs.n);
  369. for (int i = 0; i < ret.n; i++) {
  370. ret.v[i] *= k;
  371. }
  372. return ret;
  373. }
  374. GVector operator*(const GVector & lhs, const float & k)
  375. {
  376. GVector ret(lhs.n);
  377. for (int i = 0; i < ret.n; i++) {
  378. ret.v[i] *= k;
  379. }
  380. return ret;
  381. }
  382. float norm(const GVector & v)
  383. {
  384. float ret = 0;
  385. for (int i = 0; i < v.n; i++) {
  386. ret += SQR(v.v[i]);
  387. }
  388. ret = SQRT(ret);
  389. return ret;
  390. }
  391. float distance(const GVector & v, const GVector & u)
  392. {
  393. return norm(v - u);
  394. }
  395. ostream & operator<<(ostream & os, const GVector & v)
  396. {
  397. os << "[ ";
  398. for (int i = 0; i < v.n; i++) {
  399. os << setw(5) << v.v[i];
  400. if (i != v.n - 1) {
  401. os << ", ";
  402. }
  403. }
  404. os << " ]" << endl;
  405. return os;
  406. }
  407. GMatrix::GMatrix(int row, int col, float * elem)
  408. {
  409. r = row;
  410. c = col;
  411. m = new float[r*c];
  412. if (elem) {
  413. memcpy(m, elem, sizeof(float)*r*c);
  414. }
  415. else {
  416. ARR_ZERO(m, r*c);
  417. }
  418. }
  419. GMatrix::GMatrix(const GMatrix & copy)
  420. {
  421. r = copy.r;
  422. c = copy.c;
  423. m = new float[r*c];
  424. memcpy(m, copy.m, sizeof(float)*r*c);
  425. }
  426. GMatrix::~GMatrix()
  427. {
  428. if (m) {
  429. delete[] m;
  430. }
  431. m = NULL;
  432. }
  433. GMatrix & GMatrix::operator=(const GMatrix & rhs)
  434. {
  435. if (m) {
  436. delete[] m;
  437. }
  438. r = rhs.r;
  439. c = rhs.c;
  440. m = new float[r*c];
  441. memcpy(m, rhs.m, sizeof(float)*r*c);
  442. return *this;
  443. }
  444. GMatrix & GMatrix::operator+=(const GMatrix & rhs)
  445. {
  446. assert(r == rhs.r && c == rhs.c);
  447. for (int i = 0; i < r*c; i++) {
  448. m[i] += rhs.m[i];
  449. }
  450. return *this;
  451. }
  452. GMatrix & GMatrix::operator-=(const GMatrix & rhs)
  453. {
  454. assert(r == rhs.r && c == rhs.c);
  455. for (int i = 0; i < r*c; i++) {
  456. m[i] -= rhs.m[i];
  457. }
  458. return *this;
  459. }
  460. GMatrix & GMatrix::operator*=(const float & k)
  461. {
  462. for (int i = 0; i < r*c; i++) {
  463. m[i] *= k;
  464. }
  465. return *this;
  466. }
  467. GMatrix & GMatrix::operator*=(const GMatrix & rhs)
  468. {
  469. assert(c == rhs.r);
  470. c = rhs.c;
  471. float* p = new float[r*c];
  472. ARR_ZERO(p, r*c)
  473. ;
  474. for (int i = 0; i < r; i++) {
  475. for (int j = 0; j < c; j++) {
  476. for (int k = 0; k < rhs.r; k++) {
  477. p[i*c + j] += m[i*rhs.r + k] * rhs.m[k*c + j];
  478. }
  479. }
  480. }
  481. delete[] m;
  482. m = p;
  483. return *this;
  484. }
  485. GMatrix & GMatrix::operator/=(const float & k)
  486. {
  487. assert(k != 0);
  488. for (int i = 0; i < r*c; i++) {
  489. m[i] /= k;
  490. }
  491. return *this;
  492. }
  493. GMatrix GMatrix::operator+() const
  494. {
  495. return *this;
  496. }
  497. GMatrix GMatrix::operator-() const
  498. {
  499. return *this*-1;
  500. }
  501. GMatrix GMatrix::operator+(const GMatrix & rhs) const
  502. {
  503. assert(r == rhs.r && c == rhs.c);
  504. GMatrix ret(*this);
  505. ret += rhs;
  506. return ret;
  507. }
  508. GMatrix GMatrix::operator-(const GMatrix & rhs) const
  509. {
  510. assert(r == rhs.r && c == rhs.c);
  511. GMatrix ret(*this);
  512. ret -= rhs;
  513. return ret;
  514. }
  515. GMatrix GMatrix::operator*(const GMatrix & rhs) const
  516. {
  517. assert(c == rhs.r);
  518. GMatrix ret(*this);
  519. ret *= rhs;
  520. return ret;
  521. }
  522. GMatrix GMatrix::operator/(const float & k) const
  523. {
  524. GMatrix ret(*this);
  525. ret /= k;
  526. return ret;
  527. }
  528. GMatrix operator*(const GMatrix & lhs, const float & k)
  529. {
  530. GMatrix ret(lhs);
  531. ret *= k;
  532. return ret;
  533. }
  534. GMatrix operator*(const float& k, const GMatrix & rhs)
  535. {
  536. GMatrix ret(rhs);
  537. ret *= k;
  538. return ret;
  539. }
  540. GVector operator*(const GMatrix & m, const GVector & v)
  541. {
  542. assert(m.c == v.n);
  543. GVector ret(m.r);
  544. for (int i = 0; i < m.r; i++) {
  545. for (int j = 0; j < m.c; j++) {
  546. ret.v[i] += m.m[i*m.c + j] * v.v[j];
  547. }
  548. }
  549. return ret;
  550. }
  551. GMatrix operator*(const GVector & v, const GMatrix & m)
  552. {
  553. assert(m.r == 1);
  554. GMatrix ret(v.n, m.c);
  555. for (int i = 0; i < v.n; i++) {
  556. for (int j = 0; j < m.c; j++) {
  557. ret.m[i*m.c + j] = v.v[i] * m.m[j];
  558. }
  559. }
  560. return ret;
  561. }
  562. bool GMatrix::operator==(const GMatrix & rhs) const
  563. {
  564. if (r != rhs.r || c != rhs.c) {
  565. return false;
  566. }
  567. for (int i = 0; i < r*c; i++) {
  568. if (abs(m[i] - rhs.m[i]) > PRECISION) {
  569. return false;
  570. }
  571. }
  572. return true;
  573. }
  574. bool GMatrix::operator!=(const GMatrix & rhs) const
  575. {
  576. if (r != rhs.r || c != rhs.c) {
  577. return true;
  578. }
  579. for (int i = 0; i < r*c; i++) {
  580. if (abs(m[i] - rhs.m[i]) > PRECISION) {
  581. return true;
  582. }
  583. }
  584. return false;
  585. }
  586. float * GMatrix::operator[](const int idx)
  587. {
  588. assert(idx >= 0 && idx < r);
  589. return &m[idx*c];
  590. }
  591. const float * GMatrix::operator[](const int idx) const
  592. {
  593. assert(idx >= 0 && idx < r);
  594. return &m[idx*c];
  595. }
  596. GMatrix & GMatrix::SetTranspose()
  597. {
  598. int i, j;
  599. if (r == c) { //Spuare matrix
  600. for (i = 0; i < r; i++) {
  601. for (j = i+1; j < c; j++) {
  602. SWAP(float, m[i*c + j], m[j* r + i])
  603. }
  604. }
  605. }
  606. else {
  607. float *p = new float[r*c];
  608. memcpy(p, m, sizeof(float)*r*c);
  609. SWAP(int, r, c);
  610. for (i = 0; i < r; i++) {
  611. for (j = 0; j < c; j++) {
  612. m[i*c + j] = p[j*r + i];
  613. }
  614. }
  615. delete[] p;
  616. p = NULL;
  617. }
  618. return *this;
  619. }
  620. GMatrix & GMatrix::SetIdentity()
  621. {
  622. int min = MIN(r, c);
  623. SetZeros();
  624. for (int i = 0; i < min; i++) {
  625. m[i*c + i] = 1.0f;
  626. }
  627. return *this;
  628. }
  629. GMatrix & GMatrix::SetZeros()
  630. {
  631. memset(m, 0, sizeof(float)*r*c);
  632. return *this;
  633. }
  634. ostream & operator<<(ostream & os, const GMatrix & m)
  635. {
  636. float r = 0.0f;
  637. for (int i = 0; i < m.r; i++) {
  638. os << "|";
  639. for (int j = 0; j < m.c; j++) {
  640. r = EQ_ZERO(m.m[i*m.c + j], PRECISION) ? 0 : m.m[i*m.c + j];
  641. os << setw(6) << r << " ";
  642. }
  643. os << " |" << endl;
  644. }
  645. return os;
  646. }
  647. GMatrix & GMatrix::SetRowVec(const int idx, const GVector & v)
  648. {
  649. assert(idx < r && v.n == c);
  650. for (int i = 0; i < c; i++) {
  651. m[idx*c + i] = v.v[i];
  652. }
  653. return *this;
  654. }
  655. GMatrix & GMatrix::SetColVec(const int idx, const GVector & v)
  656. {
  657. assert(idx < c && v.n == r);
  658. for (int i = 0; i < r; i++) {
  659. m[i*c + idx] = v.v[i];
  660. }
  661. return *this;
  662. }
  663. GVector GMatrix::GetRowVec(const int idx) const
  664. {
  665. assert(idx < r);
  666. GVector ret(c);
  667. for (int i = 0; i < c; i++) {
  668. ret.v[i] = m[idx*c + i];
  669. }
  670. return ret;
  671. }
  672. GVector GMatrix::GetColVec(const int idx) const
  673. {
  674. assert(idx < c);
  675. GVector ret(r);
  676. for (int i = 0; i < r; i++) {
  677. ret.v[i] = m[i*c + idx];
  678. }
  679. return ret;
  680. }
  681. GMatrix & GMatrix::ExchangeRows(const int idx0, const int idx1)
  682. {
  683. GVector tmp(c);
  684. tmp = GetRowVec(idx0);
  685. SetRowVec(idx0, GetRowVec(idx1));
  686. SetRowVec(idx1, tmp);
  687. return *this;
  688. }
  689. GMatrix & GMatrix::ExchangeCols(const int idx0, const int idx1)
  690. {
  691. GVector tmp(r);
  692. tmp = GetColVec(idx0);
  693. SetColVec(idx0, GetColVec(idx1));
  694. SetColVec(idx1, tmp);
  695. return *this;
  696. }
  697. int GMatrix::GetRowNum() const
  698. {
  699. return r;
  700. }
  701. int GMatrix::GetColNum() const
  702. {
  703. return c;
  704. }
  705. bool GMatrix::IsSquare() const
  706. {
  707. return (r == c) ? true : false;
  708. }
  709. GMatrix RowEchelonForm(const GMatrix & m)
  710. {
  711. int i, j, k;
  712. int r = m.GetRowNum();
  713. int c = m.GetColNum();
  714. int n = MIN(r, c);
  715. GMatrix t(m);
  716. int shift = 0;
  717. for (i = 0; i < n; i++) {
  718. float max = ABS(t[i][i + shift]);
  719. int privot_idx = i;//�к�
  720. //�ҳ� ����ֵ�����ĵ��� �� ��������
  721. for (j = i+1; j < n; j++) {
  722. if (max < ABS(t[j][i + shift])) {
  723. max = ABS(t[j][i + shift]);
  724. privot_idx = j;
  725. }
  726. }
  727. //��������ֵ��0�Ļ�����ôֱ��������һ��
  728. if (EQ_ZERO(max, PRECISION)) {
  729. shift++;
  730. i--; //�ǵ�Ҫ������һ��
  731. continue;
  732. }
  733. //��������ֵ�����в��������У��Ǿ�Ҫ����
  734. if (i != privot_idx) {
  735. t.ExchangeRows(i, privot_idx);
  736. }
  737. //ȡ������ֵ
  738. float s = t[i][i + shift];//������Ϊ��һ���Ѿ�������ֵ�н�������������
  739. //������1
  740. for (j = i + shift; j < c; j++) {
  741. t[i][j] = t[i][j] / s;
  742. }
  743. //�ѵ�ǰ�У�����1���µ�ֵ������0
  744. for (j = i + 1; j < r; j++) {
  745. s = t[j][i + shift];
  746. for (k = i + shift; k < c; k++) {
  747. t[j][k] = t[j][k] - s * t[i][k];
  748. }
  749. }
  750. }
  751. return t;
  752. }
  753. GMatrix ReduceRowEchelonForm(const GMatrix & m)
  754. {
  755. int i, j, k;
  756. int r = m.GetRowNum();
  757. int c = m.GetColNum();
  758. int n = MIN(r, c);
  759. GMatrix t(m);
  760. int shift = 0;
  761. for (i = 0; i < n; i++) {
  762. float max = ABS(t[i][i + shift]);
  763. int privot_idx = i;//�к�
  764. //�ҳ� ����ֵ�����ĵ��� �� ��������
  765. for (j = i + 1; j < n; j++) {
  766. if (max < ABS(t[j][i + shift])) {
  767. max = ABS(t[j][i + shift]);
  768. privot_idx = j;
  769. }
  770. }
  771. //��������ֵ��0�Ļ�����ôֱ��������һ��
  772. if (EQ_ZERO(max, PRECISION)) {
  773. shift++;
  774. i--; //�ǵ�Ҫ������һ��
  775. continue;
  776. }
  777. //��������ֵ�����в��������У��Ǿ�Ҫ����
  778. if (i != privot_idx) {
  779. t.ExchangeRows(i, privot_idx);
  780. }
  781. //ȡ������ֵ
  782. float s = t[i][i + shift];//������Ϊ��һ���Ѿ�������ֵ�н�������������
  783. //������1
  784. for (j = i + shift; j < c; j++) {
  785. t[i][j] = t[i][j] / s;
  786. }
  787. //�ѵ�ǰ�У�����1����ֵ������0
  788. for (j = 0; j < r; j++) {
  789. if (i == j)
  790. continue;
  791. s = t[j][i + shift];
  792. for (k = i + shift; k < c; k++) {
  793. t[j][k] = t[j][k] - s * t[i][k];
  794. }
  795. }
  796. }
  797. return t;
  798. }
  799. float * from_arr(const GMatrix & m)
  800. {
  801. return m.m;
  802. }
  803. int Rank(const GMatrix & m)
  804. {
  805. int i, r, rank = 0;
  806. r = m.GetRowNum();
  807. GMatrix t = RowEchelonForm(m);
  808. for (i = 0; i < r; i++) {
  809. GVector rVec = t.GetRowVec(i);
  810. if (!EQ_ZERO(norm(rVec), PRECISION)) {
  811. rank++;
  812. }
  813. }
  814. return rank;
  815. }
  816. int Nullity(const GMatrix & m)
  817. {
  818. int rank = Rank(m);
  819. return m.GetColNum() - rank;
  820. }
  821. GMatrix Mij(const GMatrix & m, int rom, int col)
  822. {
  823. int i,j = 0;
  824. int r = m.GetRowNum();
  825. int c = m.GetColNum();
  826. assert(r == c);//����
  827. assert(rom < r && col < c);
  828. //����ʽ������������
  829. int nR = r - 1;
  830. int nC = c - 1;
  831. GMatrix ret(nR, nC);
  832. nR = 0;
  833. for (i = 0; i < r; i++) {
  834. nC = 0;
  835. if (i == rom) {
  836. continue;
  837. }
  838. for (j = 0; j < c; j++) {
  839. if (j == col) {
  840. continue;
  841. }
  842. ret[nR][nC] = m[i][j];
  843. nC++;
  844. }
  845. nR++;
  846. }
  847. return ret;
  848. }
  849. float Det(const GMatrix & m)
  850. {
  851. int i = 0;
  852. int r = m.GetRowNum();
  853. int c = m.GetColNum();
  854. assert(r == c);//������������ʽ
  855. float ret = 0.0f;
  856. if (r == 1) {
  857. ret = m[0][0];
  858. }
  859. else {
  860. for (i = 0; i < c; i++) {
  861. GMatrix t = Mij(m, 0, i);
  862. ret += pow(-1, 0+ i) * m[0][i] * Det(t);
  863. }
  864. }
  865. return ret;
  866. }