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dgeqpf.c 20 kB

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  1. /* f2c.h -- Standard Fortran to C header file */
  2. /** barf [ba:rf] 2. "He suggested using FORTRAN, and everybody barfed."
  3. - From The Shogakukan DICTIONARY OF NEW ENGLISH (Second edition) */
  4. #ifndef F2C_INCLUDE
  5. #define F2C_INCLUDE
  6. #include <math.h>
  7. #include <stdlib.h>
  8. #include <string.h>
  9. #include <stdio.h>
  10. #include <complex.h>
  11. #ifdef complex
  12. #undef complex
  13. #endif
  14. #ifdef I
  15. #undef I
  16. #endif
  17. #if defined(_WIN64)
  18. typedef long long BLASLONG;
  19. typedef unsigned long long BLASULONG;
  20. #else
  21. typedef long BLASLONG;
  22. typedef unsigned long BLASULONG;
  23. #endif
  24. #ifdef LAPACK_ILP64
  25. typedef BLASLONG blasint;
  26. #if defined(_WIN64)
  27. #define blasabs(x) llabs(x)
  28. #else
  29. #define blasabs(x) labs(x)
  30. #endif
  31. #else
  32. typedef int blasint;
  33. #define blasabs(x) abs(x)
  34. #endif
  35. typedef blasint integer;
  36. typedef unsigned int uinteger;
  37. typedef char *address;
  38. typedef short int shortint;
  39. typedef float real;
  40. typedef double doublereal;
  41. typedef struct { real r, i; } complex;
  42. typedef struct { doublereal r, i; } doublecomplex;
  43. static inline _Complex float Cf(complex *z) {return z->r + z->i*_Complex_I;}
  44. static inline _Complex double Cd(doublecomplex *z) {return z->r + z->i*_Complex_I;}
  45. static inline _Complex float * _pCf(complex *z) {return (_Complex float*)z;}
  46. static inline _Complex double * _pCd(doublecomplex *z) {return (_Complex double*)z;}
  47. #define pCf(z) (*_pCf(z))
  48. #define pCd(z) (*_pCd(z))
  49. typedef int logical;
  50. typedef short int shortlogical;
  51. typedef char logical1;
  52. typedef char integer1;
  53. #define TRUE_ (1)
  54. #define FALSE_ (0)
  55. /* Extern is for use with -E */
  56. #ifndef Extern
  57. #define Extern extern
  58. #endif
  59. /* I/O stuff */
  60. typedef int flag;
  61. typedef int ftnlen;
  62. typedef int ftnint;
  63. /*external read, write*/
  64. typedef struct
  65. { flag cierr;
  66. ftnint ciunit;
  67. flag ciend;
  68. char *cifmt;
  69. ftnint cirec;
  70. } cilist;
  71. /*internal read, write*/
  72. typedef struct
  73. { flag icierr;
  74. char *iciunit;
  75. flag iciend;
  76. char *icifmt;
  77. ftnint icirlen;
  78. ftnint icirnum;
  79. } icilist;
  80. /*open*/
  81. typedef struct
  82. { flag oerr;
  83. ftnint ounit;
  84. char *ofnm;
  85. ftnlen ofnmlen;
  86. char *osta;
  87. char *oacc;
  88. char *ofm;
  89. ftnint orl;
  90. char *oblnk;
  91. } olist;
  92. /*close*/
  93. typedef struct
  94. { flag cerr;
  95. ftnint cunit;
  96. char *csta;
  97. } cllist;
  98. /*rewind, backspace, endfile*/
  99. typedef struct
  100. { flag aerr;
  101. ftnint aunit;
  102. } alist;
  103. /* inquire */
  104. typedef struct
  105. { flag inerr;
  106. ftnint inunit;
  107. char *infile;
  108. ftnlen infilen;
  109. ftnint *inex; /*parameters in standard's order*/
  110. ftnint *inopen;
  111. ftnint *innum;
  112. ftnint *innamed;
  113. char *inname;
  114. ftnlen innamlen;
  115. char *inacc;
  116. ftnlen inacclen;
  117. char *inseq;
  118. ftnlen inseqlen;
  119. char *indir;
  120. ftnlen indirlen;
  121. char *infmt;
  122. ftnlen infmtlen;
  123. char *inform;
  124. ftnint informlen;
  125. char *inunf;
  126. ftnlen inunflen;
  127. ftnint *inrecl;
  128. ftnint *innrec;
  129. char *inblank;
  130. ftnlen inblanklen;
  131. } inlist;
  132. #define VOID void
  133. union Multitype { /* for multiple entry points */
  134. integer1 g;
  135. shortint h;
  136. integer i;
  137. /* longint j; */
  138. real r;
  139. doublereal d;
  140. complex c;
  141. doublecomplex z;
  142. };
  143. typedef union Multitype Multitype;
  144. struct Vardesc { /* for Namelist */
  145. char *name;
  146. char *addr;
  147. ftnlen *dims;
  148. int type;
  149. };
  150. typedef struct Vardesc Vardesc;
  151. struct Namelist {
  152. char *name;
  153. Vardesc **vars;
  154. int nvars;
  155. };
  156. typedef struct Namelist Namelist;
  157. #define abs(x) ((x) >= 0 ? (x) : -(x))
  158. #define dabs(x) (fabs(x))
  159. #define f2cmin(a,b) ((a) <= (b) ? (a) : (b))
  160. #define f2cmax(a,b) ((a) >= (b) ? (a) : (b))
  161. #define dmin(a,b) (f2cmin(a,b))
  162. #define dmax(a,b) (f2cmax(a,b))
  163. #define bit_test(a,b) ((a) >> (b) & 1)
  164. #define bit_clear(a,b) ((a) & ~((uinteger)1 << (b)))
  165. #define bit_set(a,b) ((a) | ((uinteger)1 << (b)))
  166. #define abort_() { sig_die("Fortran abort routine called", 1); }
  167. #define c_abs(z) (cabsf(Cf(z)))
  168. #define c_cos(R,Z) { pCf(R)=ccos(Cf(Z)); }
  169. #define c_div(c, a, b) {pCf(c) = Cf(a)/Cf(b);}
  170. #define z_div(c, a, b) {pCd(c) = Cd(a)/Cd(b);}
  171. #define c_exp(R, Z) {pCf(R) = cexpf(Cf(Z));}
  172. #define c_log(R, Z) {pCf(R) = clogf(Cf(Z));}
  173. #define c_sin(R, Z) {pCf(R) = csinf(Cf(Z));}
  174. //#define c_sqrt(R, Z) {*(R) = csqrtf(Cf(Z));}
  175. #define c_sqrt(R, Z) {pCf(R) = csqrtf(Cf(Z));}
  176. #define d_abs(x) (fabs(*(x)))
  177. #define d_acos(x) (acos(*(x)))
  178. #define d_asin(x) (asin(*(x)))
  179. #define d_atan(x) (atan(*(x)))
  180. #define d_atn2(x, y) (atan2(*(x),*(y)))
  181. #define d_cnjg(R, Z) { pCd(R) = conj(Cd(Z)); }
  182. #define r_cnjg(R, Z) { pCf(R) = conj(Cf(Z)); }
  183. #define d_cos(x) (cos(*(x)))
  184. #define d_cosh(x) (cosh(*(x)))
  185. #define d_dim(__a, __b) ( *(__a) > *(__b) ? *(__a) - *(__b) : 0.0 )
  186. #define d_exp(x) (exp(*(x)))
  187. #define d_imag(z) (cimag(Cd(z)))
  188. #define r_imag(z) (cimag(Cf(z)))
  189. #define d_int(__x) (*(__x)>0 ? floor(*(__x)) : -floor(- *(__x)))
  190. #define d_lg10(x) ( 0.43429448190325182765 * log(*(x)) )
  191. #define d_log(x) (log(*(x)))
  192. #define d_mod(x, y) (fmod(*(x), *(y)))
  193. #define u_nint(__x) ((__x)>=0 ? floor((__x) + .5) : -floor(.5 - (__x)))
  194. #define d_nint(x) u_nint(*(x))
  195. #define u_sign(__a,__b) ((__b) >= 0 ? ((__a) >= 0 ? (__a) : -(__a)) : -((__a) >= 0 ? (__a) : -(__a)))
  196. #define d_sign(a,b) u_sign(*(a),*(b))
  197. #define d_sin(x) (sin(*(x)))
  198. #define d_sinh(x) (sinh(*(x)))
  199. #define d_sqrt(x) (sqrt(*(x)))
  200. #define d_tan(x) (tan(*(x)))
  201. #define d_tanh(x) (tanh(*(x)))
  202. #define i_abs(x) abs(*(x))
  203. #define i_dnnt(x) ((integer)u_nint(*(x)))
  204. #define i_len(s, n) (n)
  205. #define i_nint(x) ((integer)u_nint(*(x)))
  206. #define i_sign(a,b) ((integer)u_sign((integer)*(a),(integer)*(b)))
  207. #define pow_dd(ap, bp) ( pow(*(ap), *(bp)))
  208. #define pow_si(B,E) spow_ui(*(B),*(E))
  209. #define pow_di(B,E) dpow_ui(*(B),*(E))
  210. #define pow_zi(p, a, b) {pCd(p) = zpow_ui(Cd(a), *(b));}
  211. #define pow_zz(R,A,B) {pCd(R) = cpow(Cd(A),*(B));}
  212. #define s_cat(lpp, rpp, rnp, np, llp) { ftnlen i, nc, ll; char *f__rp, *lp; ll = (llp); lp = (lpp); for(i=0; i < (int)*(np); ++i) { nc = ll; if((rnp)[i] < nc) nc = (rnp)[i]; ll -= nc; f__rp = (rpp)[i]; while(--nc >= 0) *lp++ = *(f__rp)++; } while(--ll >= 0) *lp++ = ' '; }
  213. #define s_cmp(a,b,c,d) ((integer)strncmp((a),(b),f2cmin((c),(d))))
  214. #define s_copy(A,B,C,D) { int __i,__m; for (__i=0, __m=f2cmin((C),(D)); __i<__m && (B)[__i] != 0; ++__i) (A)[__i] = (B)[__i]; }
  215. #define sig_die(s, kill) { exit(1); }
  216. #define s_stop(s, n) {exit(0);}
  217. static char junk[] = "\n@(#)LIBF77 VERSION 19990503\n";
  218. #define z_abs(z) (cabs(Cd(z)))
  219. #define z_exp(R, Z) {pCd(R) = cexp(Cd(Z));}
  220. #define z_sqrt(R, Z) {pCd(R) = csqrt(Cd(Z));}
  221. #define myexit_() break;
  222. #define mycycle() continue;
  223. #define myceiling(w) {ceil(w)}
  224. #define myhuge(w) {HUGE_VAL}
  225. #define mymaxloc_(w,s,e,n) {if (sizeof(*(w)) == sizeof(double)) dmaxloc_((w),*(s),*(e),n); else dmaxloc_((w),*(s),*(e),n);}
  226. /* procedure parameter types for -A and -C++ */
  227. #define F2C_proc_par_types 1
  228. #ifdef __cplusplus
  229. typedef logical (*L_fp)(...);
  230. #else
  231. typedef logical (*L_fp)();
  232. #endif
  233. static float spow_ui(float x, integer n) {
  234. float pow=1.0; unsigned long int u;
  235. if(n != 0) {
  236. if(n < 0) n = -n, x = 1/x;
  237. for(u = n; ; ) {
  238. if(u & 01) pow *= x;
  239. if(u >>= 1) x *= x;
  240. else break;
  241. }
  242. }
  243. return pow;
  244. }
  245. static double dpow_ui(double x, integer n) {
  246. double pow=1.0; unsigned long int u;
  247. if(n != 0) {
  248. if(n < 0) n = -n, x = 1/x;
  249. for(u = n; ; ) {
  250. if(u & 01) pow *= x;
  251. if(u >>= 1) x *= x;
  252. else break;
  253. }
  254. }
  255. return pow;
  256. }
  257. static _Complex float cpow_ui(_Complex float x, integer n) {
  258. _Complex float pow=1.0; unsigned long int u;
  259. if(n != 0) {
  260. if(n < 0) n = -n, x = 1/x;
  261. for(u = n; ; ) {
  262. if(u & 01) pow *= x;
  263. if(u >>= 1) x *= x;
  264. else break;
  265. }
  266. }
  267. return pow;
  268. }
  269. static _Complex double zpow_ui(_Complex double x, integer n) {
  270. _Complex double pow=1.0; unsigned long int u;
  271. if(n != 0) {
  272. if(n < 0) n = -n, x = 1/x;
  273. for(u = n; ; ) {
  274. if(u & 01) pow *= x;
  275. if(u >>= 1) x *= x;
  276. else break;
  277. }
  278. }
  279. return pow;
  280. }
  281. static integer pow_ii(integer x, integer n) {
  282. integer pow; unsigned long int u;
  283. if (n <= 0) {
  284. if (n == 0 || x == 1) pow = 1;
  285. else if (x != -1) pow = x == 0 ? 1/x : 0;
  286. else n = -n;
  287. }
  288. if ((n > 0) || !(n == 0 || x == 1 || x != -1)) {
  289. u = n;
  290. for(pow = 1; ; ) {
  291. if(u & 01) pow *= x;
  292. if(u >>= 1) x *= x;
  293. else break;
  294. }
  295. }
  296. return pow;
  297. }
  298. static integer dmaxloc_(double *w, integer s, integer e, integer *n)
  299. {
  300. double m; integer i, mi;
  301. for(m=w[s-1], mi=s, i=s+1; i<=e; i++)
  302. if (w[i-1]>m) mi=i ,m=w[i-1];
  303. return mi-s+1;
  304. }
  305. static integer smaxloc_(float *w, integer s, integer e, integer *n)
  306. {
  307. float m; integer i, mi;
  308. for(m=w[s-1], mi=s, i=s+1; i<=e; i++)
  309. if (w[i-1]>m) mi=i ,m=w[i-1];
  310. return mi-s+1;
  311. }
  312. static inline void cdotc_(complex *z, integer *n_, complex *x, integer *incx_, complex *y, integer *incy_) {
  313. integer n = *n_, incx = *incx_, incy = *incy_, i;
  314. _Complex float zdotc = 0.0;
  315. if (incx == 1 && incy == 1) {
  316. for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
  317. zdotc += conjf(Cf(&x[i])) * Cf(&y[i]);
  318. }
  319. } else {
  320. for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
  321. zdotc += conjf(Cf(&x[i*incx])) * Cf(&y[i*incy]);
  322. }
  323. }
  324. pCf(z) = zdotc;
  325. }
  326. static inline void zdotc_(doublecomplex *z, integer *n_, doublecomplex *x, integer *incx_, doublecomplex *y, integer *incy_) {
  327. integer n = *n_, incx = *incx_, incy = *incy_, i;
  328. _Complex double zdotc = 0.0;
  329. if (incx == 1 && incy == 1) {
  330. for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
  331. zdotc += conj(Cd(&x[i])) * Cd(&y[i]);
  332. }
  333. } else {
  334. for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
  335. zdotc += conj(Cd(&x[i*incx])) * Cd(&y[i*incy]);
  336. }
  337. }
  338. pCd(z) = zdotc;
  339. }
  340. static inline void cdotu_(complex *z, integer *n_, complex *x, integer *incx_, complex *y, integer *incy_) {
  341. integer n = *n_, incx = *incx_, incy = *incy_, i;
  342. _Complex float zdotc = 0.0;
  343. if (incx == 1 && incy == 1) {
  344. for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
  345. zdotc += Cf(&x[i]) * Cf(&y[i]);
  346. }
  347. } else {
  348. for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
  349. zdotc += Cf(&x[i*incx]) * Cf(&y[i*incy]);
  350. }
  351. }
  352. pCf(z) = zdotc;
  353. }
  354. static inline void zdotu_(doublecomplex *z, integer *n_, doublecomplex *x, integer *incx_, doublecomplex *y, integer *incy_) {
  355. integer n = *n_, incx = *incx_, incy = *incy_, i;
  356. _Complex double zdotc = 0.0;
  357. if (incx == 1 && incy == 1) {
  358. for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
  359. zdotc += Cd(&x[i]) * Cd(&y[i]);
  360. }
  361. } else {
  362. for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
  363. zdotc += Cd(&x[i*incx]) * Cd(&y[i*incy]);
  364. }
  365. }
  366. pCd(z) = zdotc;
  367. }
  368. #endif
  369. /* -- translated by f2c (version 20000121).
  370. You must link the resulting object file with the libraries:
  371. -lf2c -lm (in that order)
  372. */
  373. /* Table of constant values */
  374. static integer c__1 = 1;
  375. /* > \brief \b DGEQPF */
  376. /* =========== DOCUMENTATION =========== */
  377. /* Online html documentation available at */
  378. /* http://www.netlib.org/lapack/explore-html/ */
  379. /* > \htmlonly */
  380. /* > Download DGEQPF + dependencies */
  381. /* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dgeqpf.
  382. f"> */
  383. /* > [TGZ]</a> */
  384. /* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dgeqpf.
  385. f"> */
  386. /* > [ZIP]</a> */
  387. /* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dgeqpf.
  388. f"> */
  389. /* > [TXT]</a> */
  390. /* > \endhtmlonly */
  391. /* Definition: */
  392. /* =========== */
  393. /* SUBROUTINE DGEQPF( M, N, A, LDA, JPVT, TAU, WORK, INFO ) */
  394. /* INTEGER INFO, LDA, M, N */
  395. /* INTEGER JPVT( * ) */
  396. /* DOUBLE PRECISION A( LDA, * ), TAU( * ), WORK( * ) */
  397. /* > \par Purpose: */
  398. /* ============= */
  399. /* > */
  400. /* > \verbatim */
  401. /* > */
  402. /* > This routine is deprecated and has been replaced by routine DGEQP3. */
  403. /* > */
  404. /* > DGEQPF computes a QR factorization with column pivoting of a */
  405. /* > real M-by-N matrix A: A*P = Q*R. */
  406. /* > \endverbatim */
  407. /* Arguments: */
  408. /* ========== */
  409. /* > \param[in] M */
  410. /* > \verbatim */
  411. /* > M is INTEGER */
  412. /* > The number of rows of the matrix A. M >= 0. */
  413. /* > \endverbatim */
  414. /* > */
  415. /* > \param[in] N */
  416. /* > \verbatim */
  417. /* > N is INTEGER */
  418. /* > The number of columns of the matrix A. N >= 0 */
  419. /* > \endverbatim */
  420. /* > */
  421. /* > \param[in,out] A */
  422. /* > \verbatim */
  423. /* > A is DOUBLE PRECISION array, dimension (LDA,N) */
  424. /* > On entry, the M-by-N matrix A. */
  425. /* > On exit, the upper triangle of the array contains the */
  426. /* > f2cmin(M,N)-by-N upper triangular matrix R; the elements */
  427. /* > below the diagonal, together with the array TAU, */
  428. /* > represent the orthogonal matrix Q as a product of */
  429. /* > f2cmin(m,n) elementary reflectors. */
  430. /* > \endverbatim */
  431. /* > */
  432. /* > \param[in] LDA */
  433. /* > \verbatim */
  434. /* > LDA is INTEGER */
  435. /* > The leading dimension of the array A. LDA >= f2cmax(1,M). */
  436. /* > \endverbatim */
  437. /* > */
  438. /* > \param[in,out] JPVT */
  439. /* > \verbatim */
  440. /* > JPVT is INTEGER array, dimension (N) */
  441. /* > On entry, if JPVT(i) .ne. 0, the i-th column of A is permuted */
  442. /* > to the front of A*P (a leading column); if JPVT(i) = 0, */
  443. /* > the i-th column of A is a free column. */
  444. /* > On exit, if JPVT(i) = k, then the i-th column of A*P */
  445. /* > was the k-th column of A. */
  446. /* > \endverbatim */
  447. /* > */
  448. /* > \param[out] TAU */
  449. /* > \verbatim */
  450. /* > TAU is DOUBLE PRECISION array, dimension (f2cmin(M,N)) */
  451. /* > The scalar factors of the elementary reflectors. */
  452. /* > \endverbatim */
  453. /* > */
  454. /* > \param[out] WORK */
  455. /* > \verbatim */
  456. /* > WORK is DOUBLE PRECISION array, dimension (3*N) */
  457. /* > \endverbatim */
  458. /* > */
  459. /* > \param[out] INFO */
  460. /* > \verbatim */
  461. /* > INFO is INTEGER */
  462. /* > = 0: successful exit */
  463. /* > < 0: if INFO = -i, the i-th argument had an illegal value */
  464. /* > \endverbatim */
  465. /* Authors: */
  466. /* ======== */
  467. /* > \author Univ. of Tennessee */
  468. /* > \author Univ. of California Berkeley */
  469. /* > \author Univ. of Colorado Denver */
  470. /* > \author NAG Ltd. */
  471. /* > \date December 2016 */
  472. /* > \ingroup doubleGEcomputational */
  473. /* > \par Further Details: */
  474. /* ===================== */
  475. /* > */
  476. /* > \verbatim */
  477. /* > */
  478. /* > The matrix Q is represented as a product of elementary reflectors */
  479. /* > */
  480. /* > Q = H(1) H(2) . . . H(n) */
  481. /* > */
  482. /* > Each H(i) has the form */
  483. /* > */
  484. /* > H = I - tau * v * v**T */
  485. /* > */
  486. /* > where tau is a real scalar, and v is a real vector with */
  487. /* > v(1:i-1) = 0 and v(i) = 1; v(i+1:m) is stored on exit in A(i+1:m,i). */
  488. /* > */
  489. /* > The matrix P is represented in jpvt as follows: If */
  490. /* > jpvt(j) = i */
  491. /* > then the jth column of P is the ith canonical unit vector. */
  492. /* > */
  493. /* > Partial column norm updating strategy modified by */
  494. /* > Z. Drmac and Z. Bujanovic, Dept. of Mathematics, */
  495. /* > University of Zagreb, Croatia. */
  496. /* > -- April 2011 -- */
  497. /* > For more details see LAPACK Working Note 176. */
  498. /* > \endverbatim */
  499. /* > */
  500. /* ===================================================================== */
  501. /* Subroutine */ int dgeqpf_(integer *m, integer *n, doublereal *a, integer *
  502. lda, integer *jpvt, doublereal *tau, doublereal *work, integer *info)
  503. {
  504. /* System generated locals */
  505. integer a_dim1, a_offset, i__1, i__2, i__3;
  506. doublereal d__1, d__2;
  507. /* Local variables */
  508. doublereal temp;
  509. extern doublereal dnrm2_(integer *, doublereal *, integer *);
  510. doublereal temp2;
  511. integer i__, j;
  512. doublereal tol3z;
  513. extern /* Subroutine */ int dlarf_(char *, integer *, integer *,
  514. doublereal *, integer *, doublereal *, doublereal *, integer *,
  515. doublereal *);
  516. integer itemp;
  517. extern /* Subroutine */ int dswap_(integer *, doublereal *, integer *,
  518. doublereal *, integer *), dgeqr2_(integer *, integer *,
  519. doublereal *, integer *, doublereal *, doublereal *, integer *),
  520. dorm2r_(char *, char *, integer *, integer *, integer *,
  521. doublereal *, integer *, doublereal *, doublereal *, integer *,
  522. doublereal *, integer *);
  523. integer ma;
  524. extern doublereal dlamch_(char *);
  525. integer mn;
  526. extern /* Subroutine */ int dlarfg_(integer *, doublereal *, doublereal *,
  527. integer *, doublereal *);
  528. extern integer idamax_(integer *, doublereal *, integer *);
  529. extern /* Subroutine */ int xerbla_(char *, integer *);
  530. doublereal aii;
  531. integer pvt;
  532. /* -- LAPACK computational routine (version 3.7.0) -- */
  533. /* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
  534. /* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
  535. /* December 2016 */
  536. /* ===================================================================== */
  537. /* Test the input arguments */
  538. /* Parameter adjustments */
  539. a_dim1 = *lda;
  540. a_offset = 1 + a_dim1 * 1;
  541. a -= a_offset;
  542. --jpvt;
  543. --tau;
  544. --work;
  545. /* Function Body */
  546. *info = 0;
  547. if (*m < 0) {
  548. *info = -1;
  549. } else if (*n < 0) {
  550. *info = -2;
  551. } else if (*lda < f2cmax(1,*m)) {
  552. *info = -4;
  553. }
  554. if (*info != 0) {
  555. i__1 = -(*info);
  556. xerbla_("DGEQPF", &i__1);
  557. return 0;
  558. }
  559. mn = f2cmin(*m,*n);
  560. tol3z = sqrt(dlamch_("Epsilon"));
  561. /* Move initial columns up front */
  562. itemp = 1;
  563. i__1 = *n;
  564. for (i__ = 1; i__ <= i__1; ++i__) {
  565. if (jpvt[i__] != 0) {
  566. if (i__ != itemp) {
  567. dswap_(m, &a[i__ * a_dim1 + 1], &c__1, &a[itemp * a_dim1 + 1],
  568. &c__1);
  569. jpvt[i__] = jpvt[itemp];
  570. jpvt[itemp] = i__;
  571. } else {
  572. jpvt[i__] = i__;
  573. }
  574. ++itemp;
  575. } else {
  576. jpvt[i__] = i__;
  577. }
  578. /* L10: */
  579. }
  580. --itemp;
  581. /* Compute the QR factorization and update remaining columns */
  582. if (itemp > 0) {
  583. ma = f2cmin(itemp,*m);
  584. dgeqr2_(m, &ma, &a[a_offset], lda, &tau[1], &work[1], info);
  585. if (ma < *n) {
  586. i__1 = *n - ma;
  587. dorm2r_("Left", "Transpose", m, &i__1, &ma, &a[a_offset], lda, &
  588. tau[1], &a[(ma + 1) * a_dim1 + 1], lda, &work[1], info);
  589. }
  590. }
  591. if (itemp < mn) {
  592. /* Initialize partial column norms. The first n elements of */
  593. /* work store the exact column norms. */
  594. i__1 = *n;
  595. for (i__ = itemp + 1; i__ <= i__1; ++i__) {
  596. i__2 = *m - itemp;
  597. work[i__] = dnrm2_(&i__2, &a[itemp + 1 + i__ * a_dim1], &c__1);
  598. work[*n + i__] = work[i__];
  599. /* L20: */
  600. }
  601. /* Compute factorization */
  602. i__1 = mn;
  603. for (i__ = itemp + 1; i__ <= i__1; ++i__) {
  604. /* Determine ith pivot column and swap if necessary */
  605. i__2 = *n - i__ + 1;
  606. pvt = i__ - 1 + idamax_(&i__2, &work[i__], &c__1);
  607. if (pvt != i__) {
  608. dswap_(m, &a[pvt * a_dim1 + 1], &c__1, &a[i__ * a_dim1 + 1], &
  609. c__1);
  610. itemp = jpvt[pvt];
  611. jpvt[pvt] = jpvt[i__];
  612. jpvt[i__] = itemp;
  613. work[pvt] = work[i__];
  614. work[*n + pvt] = work[*n + i__];
  615. }
  616. /* Generate elementary reflector H(i) */
  617. if (i__ < *m) {
  618. i__2 = *m - i__ + 1;
  619. dlarfg_(&i__2, &a[i__ + i__ * a_dim1], &a[i__ + 1 + i__ *
  620. a_dim1], &c__1, &tau[i__]);
  621. } else {
  622. dlarfg_(&c__1, &a[*m + *m * a_dim1], &a[*m + *m * a_dim1], &
  623. c__1, &tau[*m]);
  624. }
  625. if (i__ < *n) {
  626. /* Apply H(i) to A(i:m,i+1:n) from the left */
  627. aii = a[i__ + i__ * a_dim1];
  628. a[i__ + i__ * a_dim1] = 1.;
  629. i__2 = *m - i__ + 1;
  630. i__3 = *n - i__;
  631. dlarf_("LEFT", &i__2, &i__3, &a[i__ + i__ * a_dim1], &c__1, &
  632. tau[i__], &a[i__ + (i__ + 1) * a_dim1], lda, &work[(*
  633. n << 1) + 1]);
  634. a[i__ + i__ * a_dim1] = aii;
  635. }
  636. /* Update partial column norms */
  637. i__2 = *n;
  638. for (j = i__ + 1; j <= i__2; ++j) {
  639. if (work[j] != 0.) {
  640. /* NOTE: The following 4 lines follow from the analysis in */
  641. /* Lapack Working Note 176. */
  642. temp = (d__1 = a[i__ + j * a_dim1], abs(d__1)) / work[j];
  643. /* Computing MAX */
  644. d__1 = 0., d__2 = (temp + 1.) * (1. - temp);
  645. temp = f2cmax(d__1,d__2);
  646. /* Computing 2nd power */
  647. d__1 = work[j] / work[*n + j];
  648. temp2 = temp * (d__1 * d__1);
  649. if (temp2 <= tol3z) {
  650. if (*m - i__ > 0) {
  651. i__3 = *m - i__;
  652. work[j] = dnrm2_(&i__3, &a[i__ + 1 + j * a_dim1],
  653. &c__1);
  654. work[*n + j] = work[j];
  655. } else {
  656. work[j] = 0.;
  657. work[*n + j] = 0.;
  658. }
  659. } else {
  660. work[j] *= sqrt(temp);
  661. }
  662. }
  663. /* L30: */
  664. }
  665. /* L40: */
  666. }
  667. }
  668. return 0;
  669. /* End of DGEQPF */
  670. } /* dgeqpf_ */