14 typedef long long BLASLONG;
15 typedef unsigned long long BLASULONG;
17 typedef long BLASLONG;
18 typedef unsigned long BLASULONG;
22 typedef BLASLONG blasint;
24 #define blasabs(x) llabs(x)
26 #define blasabs(x) labs(x)
30 #define blasabs(x) abs(x)
33 typedef blasint integer;
35 typedef unsigned int uinteger;
36 typedef char *address;
37 typedef short int shortint;
39 typedef double doublereal;
40 typedef struct { real r, i; } complex;
41 typedef struct { doublereal r, i; } doublecomplex;
43 static inline _Fcomplex Cf(complex *z) {_Fcomplex zz={z->r , z->i}; return zz;}
44 static inline _Dcomplex Cd(doublecomplex *z) {_Dcomplex zz={z->r , z->i};return zz;}
45 static inline _Fcomplex * _pCf(complex *z) {return (_Fcomplex*)z;}
46 static inline _Dcomplex * _pCd(doublecomplex *z) {return (_Dcomplex*)z;}
48 static inline _Complex float Cf(complex *z) {return z->r + z->i*_Complex_I;}
49 static inline _Complex double Cd(doublecomplex *z) {return z->r + z->i*_Complex_I;}
50 static inline _Complex float * _pCf(complex *z) {return (_Complex float*)z;}
51 static inline _Complex double * _pCd(doublecomplex *z) {return (_Complex double*)z;}
53 #define pCf(z) (*_pCf(z))
54 #define pCd(z) (*_pCd(z))
56 typedef short int shortlogical;
57 typedef char logical1;
58 typedef char integer1;
63 /* Extern is for use with -E */
74 /*external read, write*/
83 /*internal read, write*/
113 /*rewind, backspace, endfile*/
125 ftnint *inex; /*parameters in standard's order*/
151 union Multitype { /* for multiple entry points */
162 typedef union Multitype Multitype;
164 struct Vardesc { /* for Namelist */
170 typedef struct Vardesc Vardesc;
177 typedef struct Namelist Namelist;
179 #define abs(x) ((x) >= 0 ? (x) : -(x))
180 #define dabs(x) (fabs(x))
181 #define f2cmin(a,b) ((a) <= (b) ? (a) : (b))
182 #define f2cmax(a,b) ((a) >= (b) ? (a) : (b))
183 #define dmin(a,b) (f2cmin(a,b))
184 #define dmax(a,b) (f2cmax(a,b))
185 #define bit_test(a,b) ((a) >> (b) & 1)
186 #define bit_clear(a,b) ((a) & ~((uinteger)1 << (b)))
187 #define bit_set(a,b) ((a) | ((uinteger)1 << (b)))
189 #define abort_() { sig_die("Fortran abort routine called", 1); }
190 #define c_abs(z) (cabsf(Cf(z)))
191 #define c_cos(R,Z) { pCf(R)=ccos(Cf(Z)); }
193 #define c_div(c, a, b) {Cf(c)._Val[0] = (Cf(a)._Val[0]/Cf(b)._Val[0]); Cf(c)._Val[1]=(Cf(a)._Val[1]/Cf(b)._Val[1]);}
194 #define z_div(c, a, b) {Cd(c)._Val[0] = (Cd(a)._Val[0]/Cd(b)._Val[0]); Cd(c)._Val[1]=(Cd(a)._Val[1]/df(b)._Val[1]);}
196 #define c_div(c, a, b) {pCf(c) = Cf(a)/Cf(b);}
197 #define z_div(c, a, b) {pCd(c) = Cd(a)/Cd(b);}
199 #define c_exp(R, Z) {pCf(R) = cexpf(Cf(Z));}
200 #define c_log(R, Z) {pCf(R) = clogf(Cf(Z));}
201 #define c_sin(R, Z) {pCf(R) = csinf(Cf(Z));}
202 //#define c_sqrt(R, Z) {*(R) = csqrtf(Cf(Z));}
203 #define c_sqrt(R, Z) {pCf(R) = csqrtf(Cf(Z));}
204 #define d_abs(x) (fabs(*(x)))
205 #define d_acos(x) (acos(*(x)))
206 #define d_asin(x) (asin(*(x)))
207 #define d_atan(x) (atan(*(x)))
208 #define d_atn2(x, y) (atan2(*(x),*(y)))
209 #define d_cnjg(R, Z) { pCd(R) = conj(Cd(Z)); }
210 #define r_cnjg(R, Z) { pCf(R) = conjf(Cf(Z)); }
211 #define d_cos(x) (cos(*(x)))
212 #define d_cosh(x) (cosh(*(x)))
213 #define d_dim(__a, __b) ( *(__a) > *(__b) ? *(__a) - *(__b) : 0.0 )
214 #define d_exp(x) (exp(*(x)))
215 #define d_imag(z) (cimag(Cd(z)))
216 #define r_imag(z) (cimagf(Cf(z)))
217 #define d_int(__x) (*(__x)>0 ? floor(*(__x)) : -floor(- *(__x)))
218 #define r_int(__x) (*(__x)>0 ? floor(*(__x)) : -floor(- *(__x)))
219 #define d_lg10(x) ( 0.43429448190325182765 * log(*(x)) )
220 #define r_lg10(x) ( 0.43429448190325182765 * log(*(x)) )
221 #define d_log(x) (log(*(x)))
222 #define d_mod(x, y) (fmod(*(x), *(y)))
223 #define u_nint(__x) ((__x)>=0 ? floor((__x) + .5) : -floor(.5 - (__x)))
224 #define d_nint(x) u_nint(*(x))
225 #define u_sign(__a,__b) ((__b) >= 0 ? ((__a) >= 0 ? (__a) : -(__a)) : -((__a) >= 0 ? (__a) : -(__a)))
226 #define d_sign(a,b) u_sign(*(a),*(b))
227 #define r_sign(a,b) u_sign(*(a),*(b))
228 #define d_sin(x) (sin(*(x)))
229 #define d_sinh(x) (sinh(*(x)))
230 #define d_sqrt(x) (sqrt(*(x)))
231 #define d_tan(x) (tan(*(x)))
232 #define d_tanh(x) (tanh(*(x)))
233 #define i_abs(x) abs(*(x))
234 #define i_dnnt(x) ((integer)u_nint(*(x)))
235 #define i_len(s, n) (n)
236 #define i_nint(x) ((integer)u_nint(*(x)))
237 #define i_sign(a,b) ((integer)u_sign((integer)*(a),(integer)*(b)))
238 #define pow_dd(ap, bp) ( pow(*(ap), *(bp)))
239 #define pow_si(B,E) spow_ui(*(B),*(E))
240 #define pow_ri(B,E) spow_ui(*(B),*(E))
241 #define pow_di(B,E) dpow_ui(*(B),*(E))
242 #define pow_zi(p, a, b) {pCd(p) = zpow_ui(Cd(a), *(b));}
243 #define pow_ci(p, a, b) {pCf(p) = cpow_ui(Cf(a), *(b));}
244 #define pow_zz(R,A,B) {pCd(R) = cpow(Cd(A),*(B));}
245 #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++ = ' '; }
246 #define s_cmp(a,b,c,d) ((integer)strncmp((a),(b),f2cmin((c),(d))))
247 #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]; }
248 #define sig_die(s, kill) { exit(1); }
249 #define s_stop(s, n) {exit(0);}
250 static char junk[] = "\n@(#)LIBF77 VERSION 19990503\n";
251 #define z_abs(z) (cabs(Cd(z)))
252 #define z_exp(R, Z) {pCd(R) = cexp(Cd(Z));}
253 #define z_sqrt(R, Z) {pCd(R) = csqrt(Cd(Z));}
254 #define myexit_() break;
255 #define mycycle() continue;
256 #define myceiling(w) {ceil(w)}
257 #define myhuge(w) {HUGE_VAL}
258 //#define mymaxloc_(w,s,e,n) {if (sizeof(*(w)) == sizeof(double)) dmaxloc_((w),*(s),*(e),n); else dmaxloc_((w),*(s),*(e),n);}
259 #define mymaxloc(w,s,e,n) {dmaxloc_(w,*(s),*(e),n)}
261 /* procedure parameter types for -A and -C++ */
263 #define F2C_proc_par_types 1
265 typedef logical (*L_fp)(...);
267 typedef logical (*L_fp)();
270 static float spow_ui(float x, integer n) {
271 float pow=1.0; unsigned long int u;
273 if(n < 0) n = -n, x = 1/x;
282 static double dpow_ui(double x, integer n) {
283 double pow=1.0; unsigned long int u;
285 if(n < 0) n = -n, x = 1/x;
295 static _Fcomplex cpow_ui(complex x, integer n) {
296 complex pow={1.0,0.0}; unsigned long int u;
298 if(n < 0) n = -n, x.r = 1/x.r, x.i=1/x.i;
300 if(u & 01) pow.r *= x.r, pow.i *= x.i;
301 if(u >>= 1) x.r *= x.r, x.i *= x.i;
305 _Fcomplex p={pow.r, pow.i};
309 static _Complex float cpow_ui(_Complex float x, integer n) {
310 _Complex float pow=1.0; unsigned long int u;
312 if(n < 0) n = -n, x = 1/x;
323 static _Dcomplex zpow_ui(_Dcomplex x, integer n) {
324 _Dcomplex pow={1.0,0.0}; unsigned long int u;
326 if(n < 0) n = -n, x._Val[0] = 1/x._Val[0], x._Val[1] =1/x._Val[1];
328 if(u & 01) pow._Val[0] *= x._Val[0], pow._Val[1] *= x._Val[1];
329 if(u >>= 1) x._Val[0] *= x._Val[0], x._Val[1] *= x._Val[1];
333 _Dcomplex p = {pow._Val[0], pow._Val[1]};
337 static _Complex double zpow_ui(_Complex double x, integer n) {
338 _Complex double pow=1.0; unsigned long int u;
340 if(n < 0) n = -n, x = 1/x;
350 static integer pow_ii(integer x, integer n) {
351 integer pow; unsigned long int u;
353 if (n == 0 || x == 1) pow = 1;
354 else if (x != -1) pow = x == 0 ? 1/x : 0;
357 if ((n > 0) || !(n == 0 || x == 1 || x != -1)) {
367 static integer dmaxloc_(double *w, integer s, integer e, integer *n)
369 double m; integer i, mi;
370 for(m=w[s-1], mi=s, i=s+1; i<=e; i++)
371 if (w[i-1]>m) mi=i ,m=w[i-1];
374 static integer smaxloc_(float *w, integer s, integer e, integer *n)
376 float m; integer i, mi;
377 for(m=w[s-1], mi=s, i=s+1; i<=e; i++)
378 if (w[i-1]>m) mi=i ,m=w[i-1];
381 static inline void cdotc_(complex *z, integer *n_, complex *x, integer *incx_, complex *y, integer *incy_) {
382 integer n = *n_, incx = *incx_, incy = *incy_, i;
384 _Fcomplex zdotc = {0.0, 0.0};
385 if (incx == 1 && incy == 1) {
386 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
387 zdotc._Val[0] += conjf(Cf(&x[i]))._Val[0] * Cf(&y[i])._Val[0];
388 zdotc._Val[1] += conjf(Cf(&x[i]))._Val[1] * Cf(&y[i])._Val[1];
391 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
392 zdotc._Val[0] += conjf(Cf(&x[i*incx]))._Val[0] * Cf(&y[i*incy])._Val[0];
393 zdotc._Val[1] += conjf(Cf(&x[i*incx]))._Val[1] * Cf(&y[i*incy])._Val[1];
399 _Complex float zdotc = 0.0;
400 if (incx == 1 && incy == 1) {
401 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
402 zdotc += conjf(Cf(&x[i])) * Cf(&y[i]);
405 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
406 zdotc += conjf(Cf(&x[i*incx])) * Cf(&y[i*incy]);
412 static inline void zdotc_(doublecomplex *z, integer *n_, doublecomplex *x, integer *incx_, doublecomplex *y, integer *incy_) {
413 integer n = *n_, incx = *incx_, incy = *incy_, i;
415 _Dcomplex zdotc = {0.0, 0.0};
416 if (incx == 1 && incy == 1) {
417 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
418 zdotc._Val[0] += conj(Cd(&x[i]))._Val[0] * Cd(&y[i])._Val[0];
419 zdotc._Val[1] += conj(Cd(&x[i]))._Val[1] * Cd(&y[i])._Val[1];
422 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
423 zdotc._Val[0] += conj(Cd(&x[i*incx]))._Val[0] * Cd(&y[i*incy])._Val[0];
424 zdotc._Val[1] += conj(Cd(&x[i*incx]))._Val[1] * Cd(&y[i*incy])._Val[1];
430 _Complex double zdotc = 0.0;
431 if (incx == 1 && incy == 1) {
432 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
433 zdotc += conj(Cd(&x[i])) * Cd(&y[i]);
436 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
437 zdotc += conj(Cd(&x[i*incx])) * Cd(&y[i*incy]);
443 static inline void cdotu_(complex *z, integer *n_, complex *x, integer *incx_, complex *y, integer *incy_) {
444 integer n = *n_, incx = *incx_, incy = *incy_, i;
446 _Fcomplex zdotc = {0.0, 0.0};
447 if (incx == 1 && incy == 1) {
448 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
449 zdotc._Val[0] += Cf(&x[i])._Val[0] * Cf(&y[i])._Val[0];
450 zdotc._Val[1] += Cf(&x[i])._Val[1] * Cf(&y[i])._Val[1];
453 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
454 zdotc._Val[0] += Cf(&x[i*incx])._Val[0] * Cf(&y[i*incy])._Val[0];
455 zdotc._Val[1] += Cf(&x[i*incx])._Val[1] * Cf(&y[i*incy])._Val[1];
461 _Complex float zdotc = 0.0;
462 if (incx == 1 && incy == 1) {
463 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
464 zdotc += Cf(&x[i]) * Cf(&y[i]);
467 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
468 zdotc += Cf(&x[i*incx]) * Cf(&y[i*incy]);
474 static inline void zdotu_(doublecomplex *z, integer *n_, doublecomplex *x, integer *incx_, doublecomplex *y, integer *incy_) {
475 integer n = *n_, incx = *incx_, incy = *incy_, i;
477 _Dcomplex zdotc = {0.0, 0.0};
478 if (incx == 1 && incy == 1) {
479 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
480 zdotc._Val[0] += Cd(&x[i])._Val[0] * Cd(&y[i])._Val[0];
481 zdotc._Val[1] += Cd(&x[i])._Val[1] * Cd(&y[i])._Val[1];
484 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
485 zdotc._Val[0] += Cd(&x[i*incx])._Val[0] * Cd(&y[i*incy])._Val[0];
486 zdotc._Val[1] += Cd(&x[i*incx])._Val[1] * Cd(&y[i*incy])._Val[1];
492 _Complex double zdotc = 0.0;
493 if (incx == 1 && incy == 1) {
494 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
495 zdotc += Cd(&x[i]) * Cd(&y[i]);
498 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
499 zdotc += Cd(&x[i*incx]) * Cd(&y[i*incy]);
505 /* -- translated by f2c (version 20000121).
506 You must link the resulting object file with the libraries:
507 -lf2c -lm (in that order)
513 /* Table of constant values */
515 static integer c__1 = 1;
517 /* > \brief \b CHETF2_RK computes the factorization of a complex Hermitian indefinite matrix using the bounded
518 Bunch-Kaufman (rook) diagonal pivoting method (BLAS2 unblocked algorithm). */
520 /* =========== DOCUMENTATION =========== */
522 /* Online html documentation available at */
523 /* http://www.netlib.org/lapack/explore-html/ */
526 /* > Download CHETF2_RK + dependencies */
527 /* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/chetf2_
530 /* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/chetf2_
533 /* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/chetf2_
541 /* SUBROUTINE CHETF2_RK( UPLO, N, A, LDA, E, IPIV, INFO ) */
544 /* INTEGER INFO, LDA, N */
545 /* INTEGER IPIV( * ) */
546 /* COMPLEX A( LDA, * ), E ( * ) */
549 /* > \par Purpose: */
553 /* > CHETF2_RK computes the factorization of a complex Hermitian matrix A */
554 /* > using the bounded Bunch-Kaufman (rook) diagonal pivoting method: */
556 /* > A = P*U*D*(U**H)*(P**T) or A = P*L*D*(L**H)*(P**T), */
558 /* > where U (or L) is unit upper (or lower) triangular matrix, */
559 /* > U**H (or L**H) is the conjugate of U (or L), P is a permutation */
560 /* > matrix, P**T is the transpose of P, and D is Hermitian and block */
561 /* > diagonal with 1-by-1 and 2-by-2 diagonal blocks. */
563 /* > This is the unblocked version of the algorithm, calling Level 2 BLAS. */
564 /* > For more information see Further Details section. */
570 /* > \param[in] UPLO */
572 /* > UPLO is CHARACTER*1 */
573 /* > Specifies whether the upper or lower triangular part of the */
574 /* > Hermitian matrix A is stored: */
575 /* > = 'U': Upper triangular */
576 /* > = 'L': Lower triangular */
582 /* > The order of the matrix A. N >= 0. */
585 /* > \param[in,out] A */
587 /* > A is COMPLEX array, dimension (LDA,N) */
588 /* > On entry, the Hermitian matrix A. */
589 /* > If UPLO = 'U': the leading N-by-N upper triangular part */
590 /* > of A contains the upper triangular part of the matrix A, */
591 /* > and the strictly lower triangular part of A is not */
594 /* > If UPLO = 'L': the leading N-by-N lower triangular part */
595 /* > of A contains the lower triangular part of the matrix A, */
596 /* > and the strictly upper triangular part of A is not */
599 /* > On exit, contains: */
600 /* > a) ONLY diagonal elements of the Hermitian block diagonal */
601 /* > matrix D on the diagonal of A, i.e. D(k,k) = A(k,k); */
602 /* > (superdiagonal (or subdiagonal) elements of D */
603 /* > are stored on exit in array E), and */
604 /* > b) If UPLO = 'U': factor U in the superdiagonal part of A. */
605 /* > If UPLO = 'L': factor L in the subdiagonal part of A. */
608 /* > \param[in] LDA */
610 /* > LDA is INTEGER */
611 /* > The leading dimension of the array A. LDA >= f2cmax(1,N). */
614 /* > \param[out] E */
616 /* > E is COMPLEX array, dimension (N) */
617 /* > On exit, contains the superdiagonal (or subdiagonal) */
618 /* > elements of the Hermitian block diagonal matrix D */
619 /* > with 1-by-1 or 2-by-2 diagonal blocks, where */
620 /* > If UPLO = 'U': E(i) = D(i-1,i), i=2:N, E(1) is set to 0; */
621 /* > If UPLO = 'L': E(i) = D(i+1,i), i=1:N-1, E(N) is set to 0. */
623 /* > NOTE: For 1-by-1 diagonal block D(k), where */
624 /* > 1 <= k <= N, the element E(k) is set to 0 in both */
625 /* > UPLO = 'U' or UPLO = 'L' cases. */
628 /* > \param[out] IPIV */
630 /* > IPIV is INTEGER array, dimension (N) */
631 /* > IPIV describes the permutation matrix P in the factorization */
632 /* > of matrix A as follows. The absolute value of IPIV(k) */
633 /* > represents the index of row and column that were */
634 /* > interchanged with the k-th row and column. The value of UPLO */
635 /* > describes the order in which the interchanges were applied. */
636 /* > Also, the sign of IPIV represents the block structure of */
637 /* > the Hermitian block diagonal matrix D with 1-by-1 or 2-by-2 */
638 /* > diagonal blocks which correspond to 1 or 2 interchanges */
639 /* > at each factorization step. For more info see Further */
640 /* > Details section. */
642 /* > If UPLO = 'U', */
643 /* > ( in factorization order, k decreases from N to 1 ): */
644 /* > a) A single positive entry IPIV(k) > 0 means: */
645 /* > D(k,k) is a 1-by-1 diagonal block. */
646 /* > If IPIV(k) != k, rows and columns k and IPIV(k) were */
647 /* > interchanged in the matrix A(1:N,1:N); */
648 /* > If IPIV(k) = k, no interchange occurred. */
650 /* > b) A pair of consecutive negative entries */
651 /* > IPIV(k) < 0 and IPIV(k-1) < 0 means: */
652 /* > D(k-1:k,k-1:k) is a 2-by-2 diagonal block. */
653 /* > (NOTE: negative entries in IPIV appear ONLY in pairs). */
654 /* > 1) If -IPIV(k) != k, rows and columns */
655 /* > k and -IPIV(k) were interchanged */
656 /* > in the matrix A(1:N,1:N). */
657 /* > If -IPIV(k) = k, no interchange occurred. */
658 /* > 2) If -IPIV(k-1) != k-1, rows and columns */
659 /* > k-1 and -IPIV(k-1) were interchanged */
660 /* > in the matrix A(1:N,1:N). */
661 /* > If -IPIV(k-1) = k-1, no interchange occurred. */
663 /* > c) In both cases a) and b), always ABS( IPIV(k) ) <= k. */
665 /* > d) NOTE: Any entry IPIV(k) is always NONZERO on output. */
667 /* > If UPLO = 'L', */
668 /* > ( in factorization order, k increases from 1 to N ): */
669 /* > a) A single positive entry IPIV(k) > 0 means: */
670 /* > D(k,k) is a 1-by-1 diagonal block. */
671 /* > If IPIV(k) != k, rows and columns k and IPIV(k) were */
672 /* > interchanged in the matrix A(1:N,1:N). */
673 /* > If IPIV(k) = k, no interchange occurred. */
675 /* > b) A pair of consecutive negative entries */
676 /* > IPIV(k) < 0 and IPIV(k+1) < 0 means: */
677 /* > D(k:k+1,k:k+1) is a 2-by-2 diagonal block. */
678 /* > (NOTE: negative entries in IPIV appear ONLY in pairs). */
679 /* > 1) If -IPIV(k) != k, rows and columns */
680 /* > k and -IPIV(k) were interchanged */
681 /* > in the matrix A(1:N,1:N). */
682 /* > If -IPIV(k) = k, no interchange occurred. */
683 /* > 2) If -IPIV(k+1) != k+1, rows and columns */
684 /* > k-1 and -IPIV(k-1) were interchanged */
685 /* > in the matrix A(1:N,1:N). */
686 /* > If -IPIV(k+1) = k+1, no interchange occurred. */
688 /* > c) In both cases a) and b), always ABS( IPIV(k) ) >= k. */
690 /* > d) NOTE: Any entry IPIV(k) is always NONZERO on output. */
693 /* > \param[out] INFO */
695 /* > INFO is INTEGER */
696 /* > = 0: successful exit */
698 /* > < 0: If INFO = -k, the k-th argument had an illegal value */
700 /* > > 0: If INFO = k, the matrix A is singular, because: */
701 /* > If UPLO = 'U': column k in the upper */
702 /* > triangular part of A contains all zeros. */
703 /* > If UPLO = 'L': column k in the lower */
704 /* > triangular part of A contains all zeros. */
706 /* > Therefore D(k,k) is exactly zero, and superdiagonal */
707 /* > elements of column k of U (or subdiagonal elements of */
708 /* > column k of L ) are all zeros. The factorization has */
709 /* > been completed, but the block diagonal matrix D is */
710 /* > exactly singular, and division by zero will occur if */
711 /* > it is used to solve a system of equations. */
713 /* > NOTE: INFO only stores the first occurrence of */
714 /* > a singularity, any subsequent occurrence of singularity */
715 /* > is not stored in INFO even though the factorization */
716 /* > always completes. */
722 /* > \author Univ. of Tennessee */
723 /* > \author Univ. of California Berkeley */
724 /* > \author Univ. of Colorado Denver */
725 /* > \author NAG Ltd. */
727 /* > \date December 2016 */
729 /* > \ingroup complexHEcomputational */
731 /* > \par Further Details: */
732 /* ===================== */
735 /* > TODO: put further details */
738 /* > \par Contributors: */
739 /* ================== */
743 /* > December 2016, Igor Kozachenko, */
744 /* > Computer Science Division, */
745 /* > University of California, Berkeley */
747 /* > September 2007, Sven Hammarling, Nicholas J. Higham, Craig Lucas, */
748 /* > School of Mathematics, */
749 /* > University of Manchester */
751 /* > 01-01-96 - Based on modifications by */
752 /* > J. Lewis, Boeing Computer Services Company */
753 /* > A. Petitet, Computer Science Dept., */
754 /* > Univ. of Tenn., Knoxville abd , USA */
757 /* ===================================================================== */
758 /* Subroutine */ int chetf2_rk_(char *uplo, integer *n, complex *a, integer *
759 lda, complex *e, integer *ipiv, integer *info)
761 /* System generated locals */
762 integer a_dim1, a_offset, i__1, i__2, i__3, i__4, i__5, i__6;
764 complex q__1, q__2, q__3, q__4, q__5, q__6, q__7, q__8;
766 /* Local variables */
767 extern /* Subroutine */ int cher_(char *, integer *, real *, complex *,
768 integer *, complex *, integer *);
772 integer i__, j, k, p;
775 extern logical lsame_(char *, char *);
777 extern /* Subroutine */ int cswap_(integer *, complex *, integer *,
778 complex *, integer *);
779 integer itemp, kstep;
786 extern real slapy2_(real *, real *);
790 extern integer icamax_(integer *, complex *, integer *);
791 extern real slamch_(char *);
793 extern /* Subroutine */ int csscal_(integer *, real *, complex *, integer
794 *), xerbla_(char *, integer *, ftnlen);
799 /* -- LAPACK computational routine (version 3.7.0) -- */
800 /* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
801 /* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
805 /* ====================================================================== */
809 /* Test the input parameters. */
811 /* Parameter adjustments */
813 a_offset = 1 + a_dim1 * 1;
820 upper = lsame_(uplo, "U");
821 if (! upper && ! lsame_(uplo, "L")) {
825 } else if (*lda < f2cmax(1,*n)) {
830 xerbla_("CHETF2_RK", &i__1, (ftnlen)9);
834 /* Initialize ALPHA for use in choosing pivot block size. */
836 alpha = (sqrt(17.f) + 1.f) / 8.f;
838 /* Compute machine safe minimum */
840 sfmin = slamch_("S");
844 /* Factorize A as U*D*U**H using the upper triangle of A */
846 /* Initialize the first entry of array E, where superdiagonal */
847 /* elements of D are stored */
849 e[1].r = 0.f, e[1].i = 0.f;
851 /* K is the main loop index, decreasing from N to 1 in steps of */
857 /* If K < 1, exit from loop */
865 /* Determine rows and columns to be interchanged and whether */
866 /* a 1-by-1 or 2-by-2 pivot block will be used */
868 i__1 = k + k * a_dim1;
869 absakk = (r__1 = a[i__1].r, abs(r__1));
871 /* IMAX is the row-index of the largest off-diagonal element in */
872 /* column K, and COLMAX is its absolute value. */
873 /* Determine both COLMAX and IMAX. */
877 imax = icamax_(&i__1, &a[k * a_dim1 + 1], &c__1);
878 i__1 = imax + k * a_dim1;
879 colmax = (r__1 = a[i__1].r, abs(r__1)) + (r__2 = r_imag(&a[imax +
880 k * a_dim1]), abs(r__2));
885 if (f2cmax(absakk,colmax) == 0.f) {
887 /* Column K is zero or underflow: set INFO and continue */
893 i__1 = k + k * a_dim1;
894 i__2 = k + k * a_dim1;
896 a[i__1].r = r__1, a[i__1].i = 0.f;
898 /* Set E( K ) to zero */
902 e[i__1].r = 0.f, e[i__1].i = 0.f;
907 /* ============================================================ */
909 /* BEGIN pivot search */
912 /* Equivalent to testing for ABSAKK.GE.ALPHA*COLMAX */
913 /* (used to handle NaN and Inf) */
915 if (! (absakk < alpha * colmax)) {
917 /* no interchange, use 1-by-1 pivot block */
925 /* Loop until pivot found */
929 /* BEGIN pivot search loop body */
932 /* JMAX is the column-index of the largest off-diagonal */
933 /* element in row IMAX, and ROWMAX is its absolute value. */
934 /* Determine both ROWMAX and JMAX. */
938 jmax = imax + icamax_(&i__1, &a[imax + (imax + 1) *
940 i__1 = imax + jmax * a_dim1;
941 rowmax = (r__1 = a[i__1].r, abs(r__1)) + (r__2 = r_imag(&
942 a[imax + jmax * a_dim1]), abs(r__2));
949 itemp = icamax_(&i__1, &a[imax * a_dim1 + 1], &c__1);
950 i__1 = itemp + imax * a_dim1;
951 stemp = (r__1 = a[i__1].r, abs(r__1)) + (r__2 = r_imag(&a[
952 itemp + imax * a_dim1]), abs(r__2));
953 if (stemp > rowmax) {
960 /* Equivalent to testing for */
961 /* ABS( REAL( W( IMAX,KW-1 ) ) ).GE.ALPHA*ROWMAX */
962 /* (used to handle NaN and Inf) */
964 i__1 = imax + imax * a_dim1;
965 if (! ((r__1 = a[i__1].r, abs(r__1)) < alpha * rowmax)) {
967 /* interchange rows and columns K and IMAX, */
968 /* use 1-by-1 pivot block */
974 /* Equivalent to testing for ROWMAX.EQ.COLMAX, */
975 /* (used to handle NaN and Inf) */
977 } else if (p == jmax || rowmax <= colmax) {
979 /* interchange rows and columns K-1 and IMAX, */
980 /* use 2-by-2 pivot block */
989 /* Pivot not found: set params and repeat */
996 /* END pivot search loop body */
1004 /* END pivot search */
1006 /* ============================================================ */
1008 /* KK is the column of A where pivoting step stopped */
1012 /* For only a 2x2 pivot, interchange rows and columns K and P */
1013 /* in the leading submatrix A(1:k,1:k) */
1015 if (kstep == 2 && p != k) {
1016 /* (1) Swap columnar parts */
1019 cswap_(&i__1, &a[k * a_dim1 + 1], &c__1, &a[p * a_dim1 +
1022 /* (2) Swap and conjugate middle parts */
1024 for (j = p + 1; j <= i__1; ++j) {
1025 r_cnjg(&q__1, &a[j + k * a_dim1]);
1026 t.r = q__1.r, t.i = q__1.i;
1027 i__2 = j + k * a_dim1;
1028 r_cnjg(&q__1, &a[p + j * a_dim1]);
1029 a[i__2].r = q__1.r, a[i__2].i = q__1.i;
1030 i__2 = p + j * a_dim1;
1031 a[i__2].r = t.r, a[i__2].i = t.i;
1034 /* (3) Swap and conjugate corner elements at row-col interserction */
1035 i__1 = p + k * a_dim1;
1036 r_cnjg(&q__1, &a[p + k * a_dim1]);
1037 a[i__1].r = q__1.r, a[i__1].i = q__1.i;
1038 /* (4) Swap diagonal elements at row-col intersection */
1039 i__1 = k + k * a_dim1;
1041 i__1 = k + k * a_dim1;
1042 i__2 = p + p * a_dim1;
1044 a[i__1].r = r__1, a[i__1].i = 0.f;
1045 i__1 = p + p * a_dim1;
1046 a[i__1].r = r1, a[i__1].i = 0.f;
1048 /* Convert upper triangle of A into U form by applying */
1049 /* the interchanges in columns k+1:N. */
1053 cswap_(&i__1, &a[k + (k + 1) * a_dim1], lda, &a[p + (k +
1059 /* For both 1x1 and 2x2 pivots, interchange rows and */
1060 /* columns KK and KP in the leading submatrix A(1:k,1:k) */
1063 /* (1) Swap columnar parts */
1066 cswap_(&i__1, &a[kk * a_dim1 + 1], &c__1, &a[kp * a_dim1
1069 /* (2) Swap and conjugate middle parts */
1071 for (j = kp + 1; j <= i__1; ++j) {
1072 r_cnjg(&q__1, &a[j + kk * a_dim1]);
1073 t.r = q__1.r, t.i = q__1.i;
1074 i__2 = j + kk * a_dim1;
1075 r_cnjg(&q__1, &a[kp + j * a_dim1]);
1076 a[i__2].r = q__1.r, a[i__2].i = q__1.i;
1077 i__2 = kp + j * a_dim1;
1078 a[i__2].r = t.r, a[i__2].i = t.i;
1081 /* (3) Swap and conjugate corner elements at row-col interserction */
1082 i__1 = kp + kk * a_dim1;
1083 r_cnjg(&q__1, &a[kp + kk * a_dim1]);
1084 a[i__1].r = q__1.r, a[i__1].i = q__1.i;
1085 /* (4) Swap diagonal elements at row-col intersection */
1086 i__1 = kk + kk * a_dim1;
1088 i__1 = kk + kk * a_dim1;
1089 i__2 = kp + kp * a_dim1;
1091 a[i__1].r = r__1, a[i__1].i = 0.f;
1092 i__1 = kp + kp * a_dim1;
1093 a[i__1].r = r1, a[i__1].i = 0.f;
1096 /* (*) Make sure that diagonal element of pivot is real */
1097 i__1 = k + k * a_dim1;
1098 i__2 = k + k * a_dim1;
1100 a[i__1].r = r__1, a[i__1].i = 0.f;
1101 /* (5) Swap row elements */
1102 i__1 = k - 1 + k * a_dim1;
1103 t.r = a[i__1].r, t.i = a[i__1].i;
1104 i__1 = k - 1 + k * a_dim1;
1105 i__2 = kp + k * a_dim1;
1106 a[i__1].r = a[i__2].r, a[i__1].i = a[i__2].i;
1107 i__1 = kp + k * a_dim1;
1108 a[i__1].r = t.r, a[i__1].i = t.i;
1111 /* Convert upper triangle of A into U form by applying */
1112 /* the interchanges in columns k+1:N. */
1116 cswap_(&i__1, &a[kk + (k + 1) * a_dim1], lda, &a[kp + (k
1117 + 1) * a_dim1], lda);
1121 /* (*) Make sure that diagonal element of pivot is real */
1122 i__1 = k + k * a_dim1;
1123 i__2 = k + k * a_dim1;
1125 a[i__1].r = r__1, a[i__1].i = 0.f;
1127 i__1 = k - 1 + (k - 1) * a_dim1;
1128 i__2 = k - 1 + (k - 1) * a_dim1;
1130 a[i__1].r = r__1, a[i__1].i = 0.f;
1134 /* Update the leading submatrix */
1138 /* 1-by-1 pivot block D(k): column k now holds */
1140 /* W(k) = U(k)*D(k) */
1142 /* where U(k) is the k-th column of U */
1146 /* Perform a rank-1 update of A(1:k-1,1:k-1) and */
1147 /* store U(k) in column k */
1149 i__1 = k + k * a_dim1;
1150 if ((r__1 = a[i__1].r, abs(r__1)) >= sfmin) {
1152 /* Perform a rank-1 update of A(1:k-1,1:k-1) as */
1153 /* A := A - U(k)*D(k)*U(k)**T */
1154 /* = A - W(k)*1/D(k)*W(k)**T */
1156 i__1 = k + k * a_dim1;
1157 d11 = 1.f / a[i__1].r;
1160 cher_(uplo, &i__1, &r__1, &a[k * a_dim1 + 1], &c__1, &
1163 /* Store U(k) in column k */
1166 csscal_(&i__1, &d11, &a[k * a_dim1 + 1], &c__1);
1169 /* Store L(k) in column K */
1171 i__1 = k + k * a_dim1;
1174 for (ii = 1; ii <= i__1; ++ii) {
1175 i__2 = ii + k * a_dim1;
1176 i__3 = ii + k * a_dim1;
1177 q__1.r = a[i__3].r / d11, q__1.i = a[i__3].i /
1179 a[i__2].r = q__1.r, a[i__2].i = q__1.i;
1183 /* Perform a rank-1 update of A(k+1:n,k+1:n) as */
1184 /* A := A - U(k)*D(k)*U(k)**T */
1185 /* = A - W(k)*(1/D(k))*W(k)**T */
1186 /* = A - (W(k)/D(k))*(D(k))*(W(k)/D(K))**T */
1190 cher_(uplo, &i__1, &r__1, &a[k * a_dim1 + 1], &c__1, &
1194 /* Store the superdiagonal element of D in array E */
1197 e[i__1].r = 0.f, e[i__1].i = 0.f;
1203 /* 2-by-2 pivot block D(k): columns k and k-1 now hold */
1205 /* ( W(k-1) W(k) ) = ( U(k-1) U(k) )*D(k) */
1207 /* where U(k) and U(k-1) are the k-th and (k-1)-th columns */
1210 /* Perform a rank-2 update of A(1:k-2,1:k-2) as */
1212 /* A := A - ( U(k-1) U(k) )*D(k)*( U(k-1) U(k) )**T */
1213 /* = A - ( ( A(k-1)A(k) )*inv(D(k)) ) * ( A(k-1)A(k) )**T */
1215 /* and store L(k) and L(k+1) in columns k and k+1 */
1219 i__1 = k - 1 + k * a_dim1;
1221 r__2 = r_imag(&a[k - 1 + k * a_dim1]);
1222 d__ = slapy2_(&r__1, &r__2);
1223 i__1 = k + k * a_dim1;
1224 q__1.r = a[i__1].r / d__, q__1.i = a[i__1].i / d__;
1226 i__1 = k - 1 + (k - 1) * a_dim1;
1227 q__1.r = a[i__1].r / d__, q__1.i = a[i__1].i / d__;
1229 i__1 = k - 1 + k * a_dim1;
1230 q__1.r = a[i__1].r / d__, q__1.i = a[i__1].i / d__;
1231 d12.r = q__1.r, d12.i = q__1.i;
1232 tt = 1.f / (d11 * d22 - 1.f);
1234 for (j = k - 2; j >= 1; --j) {
1236 /* Compute D21 * ( W(k)W(k+1) ) * inv(D(k)) for row J */
1238 i__1 = j + (k - 1) * a_dim1;
1239 q__3.r = d11 * a[i__1].r, q__3.i = d11 * a[i__1].i;
1240 r_cnjg(&q__5, &d12);
1241 i__2 = j + k * a_dim1;
1242 q__4.r = q__5.r * a[i__2].r - q__5.i * a[i__2].i,
1243 q__4.i = q__5.r * a[i__2].i + q__5.i * a[i__2]
1245 q__2.r = q__3.r - q__4.r, q__2.i = q__3.i - q__4.i;
1246 q__1.r = tt * q__2.r, q__1.i = tt * q__2.i;
1247 wkm1.r = q__1.r, wkm1.i = q__1.i;
1248 i__1 = j + k * a_dim1;
1249 q__3.r = d22 * a[i__1].r, q__3.i = d22 * a[i__1].i;
1250 i__2 = j + (k - 1) * a_dim1;
1251 q__4.r = d12.r * a[i__2].r - d12.i * a[i__2].i,
1252 q__4.i = d12.r * a[i__2].i + d12.i * a[i__2]
1254 q__2.r = q__3.r - q__4.r, q__2.i = q__3.i - q__4.i;
1255 q__1.r = tt * q__2.r, q__1.i = tt * q__2.i;
1256 wk.r = q__1.r, wk.i = q__1.i;
1258 /* Perform a rank-2 update of A(1:k-2,1:k-2) */
1260 for (i__ = j; i__ >= 1; --i__) {
1261 i__1 = i__ + j * a_dim1;
1262 i__2 = i__ + j * a_dim1;
1263 i__3 = i__ + k * a_dim1;
1264 q__4.r = a[i__3].r / d__, q__4.i = a[i__3].i /
1267 q__3.r = q__4.r * q__5.r - q__4.i * q__5.i,
1268 q__3.i = q__4.r * q__5.i + q__4.i *
1270 q__2.r = a[i__2].r - q__3.r, q__2.i = a[i__2].i -
1272 i__4 = i__ + (k - 1) * a_dim1;
1273 q__7.r = a[i__4].r / d__, q__7.i = a[i__4].i /
1275 r_cnjg(&q__8, &wkm1);
1276 q__6.r = q__7.r * q__8.r - q__7.i * q__8.i,
1277 q__6.i = q__7.r * q__8.i + q__7.i *
1279 q__1.r = q__2.r - q__6.r, q__1.i = q__2.i -
1281 a[i__1].r = q__1.r, a[i__1].i = q__1.i;
1285 /* Store U(k) and U(k-1) in cols k and k-1 for row J */
1287 i__1 = j + k * a_dim1;
1288 q__1.r = wk.r / d__, q__1.i = wk.i / d__;
1289 a[i__1].r = q__1.r, a[i__1].i = q__1.i;
1290 i__1 = j + (k - 1) * a_dim1;
1291 q__1.r = wkm1.r / d__, q__1.i = wkm1.i / d__;
1292 a[i__1].r = q__1.r, a[i__1].i = q__1.i;
1293 /* (*) Make sure that diagonal element of pivot is real */
1294 i__1 = j + j * a_dim1;
1295 i__2 = j + j * a_dim1;
1297 q__1.r = r__1, q__1.i = 0.f;
1298 a[i__1].r = q__1.r, a[i__1].i = q__1.i;
1305 /* Copy superdiagonal elements of D(K) to E(K) and */
1306 /* ZERO out superdiagonal entry of A */
1309 i__2 = k - 1 + k * a_dim1;
1310 e[i__1].r = a[i__2].r, e[i__1].i = a[i__2].i;
1312 e[i__1].r = 0.f, e[i__1].i = 0.f;
1313 i__1 = k - 1 + k * a_dim1;
1314 a[i__1].r = 0.f, a[i__1].i = 0.f;
1318 /* End column K is nonsingular */
1322 /* Store details of the interchanges in IPIV */
1331 /* Decrease K and return to the start of the main loop */
1341 /* Factorize A as L*D*L**H using the lower triangle of A */
1343 /* Initialize the unused last entry of the subdiagonal array E. */
1346 e[i__1].r = 0.f, e[i__1].i = 0.f;
1348 /* K is the main loop index, increasing from 1 to N in steps of */
1354 /* If K > N, exit from loop */
1362 /* Determine rows and columns to be interchanged and whether */
1363 /* a 1-by-1 or 2-by-2 pivot block will be used */
1365 i__1 = k + k * a_dim1;
1366 absakk = (r__1 = a[i__1].r, abs(r__1));
1368 /* IMAX is the row-index of the largest off-diagonal element in */
1369 /* column K, and COLMAX is its absolute value. */
1370 /* Determine both COLMAX and IMAX. */
1374 imax = k + icamax_(&i__1, &a[k + 1 + k * a_dim1], &c__1);
1375 i__1 = imax + k * a_dim1;
1376 colmax = (r__1 = a[i__1].r, abs(r__1)) + (r__2 = r_imag(&a[imax +
1377 k * a_dim1]), abs(r__2));
1382 if (f2cmax(absakk,colmax) == 0.f) {
1384 /* Column K is zero or underflow: set INFO and continue */
1390 i__1 = k + k * a_dim1;
1391 i__2 = k + k * a_dim1;
1393 a[i__1].r = r__1, a[i__1].i = 0.f;
1395 /* Set E( K ) to zero */
1399 e[i__1].r = 0.f, e[i__1].i = 0.f;
1404 /* ============================================================ */
1406 /* BEGIN pivot search */
1409 /* Equivalent to testing for ABSAKK.GE.ALPHA*COLMAX */
1410 /* (used to handle NaN and Inf) */
1412 if (! (absakk < alpha * colmax)) {
1414 /* no interchange, use 1-by-1 pivot block */
1422 /* Loop until pivot found */
1426 /* BEGIN pivot search loop body */
1429 /* JMAX is the column-index of the largest off-diagonal */
1430 /* element in row IMAX, and ROWMAX is its absolute value. */
1431 /* Determine both ROWMAX and JMAX. */
1435 jmax = k - 1 + icamax_(&i__1, &a[imax + k * a_dim1], lda);
1436 i__1 = imax + jmax * a_dim1;
1437 rowmax = (r__1 = a[i__1].r, abs(r__1)) + (r__2 = r_imag(&
1438 a[imax + jmax * a_dim1]), abs(r__2));
1445 itemp = imax + icamax_(&i__1, &a[imax + 1 + imax * a_dim1]
1447 i__1 = itemp + imax * a_dim1;
1448 stemp = (r__1 = a[i__1].r, abs(r__1)) + (r__2 = r_imag(&a[
1449 itemp + imax * a_dim1]), abs(r__2));
1450 if (stemp > rowmax) {
1457 /* Equivalent to testing for */
1458 /* ABS( REAL( W( IMAX,KW-1 ) ) ).GE.ALPHA*ROWMAX */
1459 /* (used to handle NaN and Inf) */
1461 i__1 = imax + imax * a_dim1;
1462 if (! ((r__1 = a[i__1].r, abs(r__1)) < alpha * rowmax)) {
1464 /* interchange rows and columns K and IMAX, */
1465 /* use 1-by-1 pivot block */
1471 /* Equivalent to testing for ROWMAX.EQ.COLMAX, */
1472 /* (used to handle NaN and Inf) */
1474 } else if (p == jmax || rowmax <= colmax) {
1476 /* interchange rows and columns K+1 and IMAX, */
1477 /* use 2-by-2 pivot block */
1486 /* Pivot not found: set params and repeat */
1494 /* END pivot search loop body */
1502 /* END pivot search */
1504 /* ============================================================ */
1506 /* KK is the column of A where pivoting step stopped */
1510 /* For only a 2x2 pivot, interchange rows and columns K and P */
1511 /* in the trailing submatrix A(k:n,k:n) */
1513 if (kstep == 2 && p != k) {
1514 /* (1) Swap columnar parts */
1517 cswap_(&i__1, &a[p + 1 + k * a_dim1], &c__1, &a[p + 1 + p
1520 /* (2) Swap and conjugate middle parts */
1522 for (j = k + 1; j <= i__1; ++j) {
1523 r_cnjg(&q__1, &a[j + k * a_dim1]);
1524 t.r = q__1.r, t.i = q__1.i;
1525 i__2 = j + k * a_dim1;
1526 r_cnjg(&q__1, &a[p + j * a_dim1]);
1527 a[i__2].r = q__1.r, a[i__2].i = q__1.i;
1528 i__2 = p + j * a_dim1;
1529 a[i__2].r = t.r, a[i__2].i = t.i;
1532 /* (3) Swap and conjugate corner elements at row-col interserction */
1533 i__1 = p + k * a_dim1;
1534 r_cnjg(&q__1, &a[p + k * a_dim1]);
1535 a[i__1].r = q__1.r, a[i__1].i = q__1.i;
1536 /* (4) Swap diagonal elements at row-col intersection */
1537 i__1 = k + k * a_dim1;
1539 i__1 = k + k * a_dim1;
1540 i__2 = p + p * a_dim1;
1542 a[i__1].r = r__1, a[i__1].i = 0.f;
1543 i__1 = p + p * a_dim1;
1544 a[i__1].r = r1, a[i__1].i = 0.f;
1546 /* Convert lower triangle of A into L form by applying */
1547 /* the interchanges in columns 1:k-1. */
1551 cswap_(&i__1, &a[k + a_dim1], lda, &a[p + a_dim1], lda);
1556 /* For both 1x1 and 2x2 pivots, interchange rows and */
1557 /* columns KK and KP in the trailing submatrix A(k:n,k:n) */
1560 /* (1) Swap columnar parts */
1563 cswap_(&i__1, &a[kp + 1 + kk * a_dim1], &c__1, &a[kp + 1
1564 + kp * a_dim1], &c__1);
1566 /* (2) Swap and conjugate middle parts */
1568 for (j = kk + 1; j <= i__1; ++j) {
1569 r_cnjg(&q__1, &a[j + kk * a_dim1]);
1570 t.r = q__1.r, t.i = q__1.i;
1571 i__2 = j + kk * a_dim1;
1572 r_cnjg(&q__1, &a[kp + j * a_dim1]);
1573 a[i__2].r = q__1.r, a[i__2].i = q__1.i;
1574 i__2 = kp + j * a_dim1;
1575 a[i__2].r = t.r, a[i__2].i = t.i;
1578 /* (3) Swap and conjugate corner elements at row-col interserction */
1579 i__1 = kp + kk * a_dim1;
1580 r_cnjg(&q__1, &a[kp + kk * a_dim1]);
1581 a[i__1].r = q__1.r, a[i__1].i = q__1.i;
1582 /* (4) Swap diagonal elements at row-col intersection */
1583 i__1 = kk + kk * a_dim1;
1585 i__1 = kk + kk * a_dim1;
1586 i__2 = kp + kp * a_dim1;
1588 a[i__1].r = r__1, a[i__1].i = 0.f;
1589 i__1 = kp + kp * a_dim1;
1590 a[i__1].r = r1, a[i__1].i = 0.f;
1593 /* (*) Make sure that diagonal element of pivot is real */
1594 i__1 = k + k * a_dim1;
1595 i__2 = k + k * a_dim1;
1597 a[i__1].r = r__1, a[i__1].i = 0.f;
1598 /* (5) Swap row elements */
1599 i__1 = k + 1 + k * a_dim1;
1600 t.r = a[i__1].r, t.i = a[i__1].i;
1601 i__1 = k + 1 + k * a_dim1;
1602 i__2 = kp + k * a_dim1;
1603 a[i__1].r = a[i__2].r, a[i__1].i = a[i__2].i;
1604 i__1 = kp + k * a_dim1;
1605 a[i__1].r = t.r, a[i__1].i = t.i;
1608 /* Convert lower triangle of A into L form by applying */
1609 /* the interchanges in columns 1:k-1. */
1613 cswap_(&i__1, &a[kk + a_dim1], lda, &a[kp + a_dim1], lda);
1617 /* (*) Make sure that diagonal element of pivot is real */
1618 i__1 = k + k * a_dim1;
1619 i__2 = k + k * a_dim1;
1621 a[i__1].r = r__1, a[i__1].i = 0.f;
1623 i__1 = k + 1 + (k + 1) * a_dim1;
1624 i__2 = k + 1 + (k + 1) * a_dim1;
1626 a[i__1].r = r__1, a[i__1].i = 0.f;
1630 /* Update the trailing submatrix */
1634 /* 1-by-1 pivot block D(k): column k of A now holds */
1636 /* W(k) = L(k)*D(k), */
1638 /* where L(k) is the k-th column of L */
1642 /* Perform a rank-1 update of A(k+1:n,k+1:n) and */
1643 /* store L(k) in column k */
1645 /* Handle division by a small number */
1647 i__1 = k + k * a_dim1;
1648 if ((r__1 = a[i__1].r, abs(r__1)) >= sfmin) {
1650 /* Perform a rank-1 update of A(k+1:n,k+1:n) as */
1651 /* A := A - L(k)*D(k)*L(k)**T */
1652 /* = A - W(k)*(1/D(k))*W(k)**T */
1654 i__1 = k + k * a_dim1;
1655 d11 = 1.f / a[i__1].r;
1658 cher_(uplo, &i__1, &r__1, &a[k + 1 + k * a_dim1], &
1659 c__1, &a[k + 1 + (k + 1) * a_dim1], lda);
1661 /* Store L(k) in column k */
1664 csscal_(&i__1, &d11, &a[k + 1 + k * a_dim1], &c__1);
1667 /* Store L(k) in column k */
1669 i__1 = k + k * a_dim1;
1672 for (ii = k + 1; ii <= i__1; ++ii) {
1673 i__2 = ii + k * a_dim1;
1674 i__3 = ii + k * a_dim1;
1675 q__1.r = a[i__3].r / d11, q__1.i = a[i__3].i /
1677 a[i__2].r = q__1.r, a[i__2].i = q__1.i;
1681 /* Perform a rank-1 update of A(k+1:n,k+1:n) as */
1682 /* A := A - L(k)*D(k)*L(k)**T */
1683 /* = A - W(k)*(1/D(k))*W(k)**T */
1684 /* = A - (W(k)/D(k))*(D(k))*(W(k)/D(K))**T */
1688 cher_(uplo, &i__1, &r__1, &a[k + 1 + k * a_dim1], &
1689 c__1, &a[k + 1 + (k + 1) * a_dim1], lda);
1692 /* Store the subdiagonal element of D in array E */
1695 e[i__1].r = 0.f, e[i__1].i = 0.f;
1701 /* 2-by-2 pivot block D(k): columns k and k+1 now hold */
1703 /* ( W(k) W(k+1) ) = ( L(k) L(k+1) )*D(k) */
1705 /* where L(k) and L(k+1) are the k-th and (k+1)-th columns */
1709 /* Perform a rank-2 update of A(k+2:n,k+2:n) as */
1711 /* A := A - ( L(k) L(k+1) ) * D(k) * ( L(k) L(k+1) )**T */
1712 /* = A - ( ( A(k)A(k+1) )*inv(D(k) ) * ( A(k)A(k+1) )**T */
1714 /* and store L(k) and L(k+1) in columns k and k+1 */
1718 i__1 = k + 1 + k * a_dim1;
1720 r__2 = r_imag(&a[k + 1 + k * a_dim1]);
1721 d__ = slapy2_(&r__1, &r__2);
1722 i__1 = k + 1 + (k + 1) * a_dim1;
1723 d11 = a[i__1].r / d__;
1724 i__1 = k + k * a_dim1;
1725 d22 = a[i__1].r / d__;
1726 i__1 = k + 1 + k * a_dim1;
1727 q__1.r = a[i__1].r / d__, q__1.i = a[i__1].i / d__;
1728 d21.r = q__1.r, d21.i = q__1.i;
1729 tt = 1.f / (d11 * d22 - 1.f);
1732 for (j = k + 2; j <= i__1; ++j) {
1734 /* Compute D21 * ( W(k)W(k+1) ) * inv(D(k)) for row J */
1736 i__2 = j + k * a_dim1;
1737 q__3.r = d11 * a[i__2].r, q__3.i = d11 * a[i__2].i;
1738 i__3 = j + (k + 1) * a_dim1;
1739 q__4.r = d21.r * a[i__3].r - d21.i * a[i__3].i,
1740 q__4.i = d21.r * a[i__3].i + d21.i * a[i__3]
1742 q__2.r = q__3.r - q__4.r, q__2.i = q__3.i - q__4.i;
1743 q__1.r = tt * q__2.r, q__1.i = tt * q__2.i;
1744 wk.r = q__1.r, wk.i = q__1.i;
1745 i__2 = j + (k + 1) * a_dim1;
1746 q__3.r = d22 * a[i__2].r, q__3.i = d22 * a[i__2].i;
1747 r_cnjg(&q__5, &d21);
1748 i__3 = j + k * a_dim1;
1749 q__4.r = q__5.r * a[i__3].r - q__5.i * a[i__3].i,
1750 q__4.i = q__5.r * a[i__3].i + q__5.i * a[i__3]
1752 q__2.r = q__3.r - q__4.r, q__2.i = q__3.i - q__4.i;
1753 q__1.r = tt * q__2.r, q__1.i = tt * q__2.i;
1754 wkp1.r = q__1.r, wkp1.i = q__1.i;
1756 /* Perform a rank-2 update of A(k+2:n,k+2:n) */
1759 for (i__ = j; i__ <= i__2; ++i__) {
1760 i__3 = i__ + j * a_dim1;
1761 i__4 = i__ + j * a_dim1;
1762 i__5 = i__ + k * a_dim1;
1763 q__4.r = a[i__5].r / d__, q__4.i = a[i__5].i /
1766 q__3.r = q__4.r * q__5.r - q__4.i * q__5.i,
1767 q__3.i = q__4.r * q__5.i + q__4.i *
1769 q__2.r = a[i__4].r - q__3.r, q__2.i = a[i__4].i -
1771 i__6 = i__ + (k + 1) * a_dim1;
1772 q__7.r = a[i__6].r / d__, q__7.i = a[i__6].i /
1774 r_cnjg(&q__8, &wkp1);
1775 q__6.r = q__7.r * q__8.r - q__7.i * q__8.i,
1776 q__6.i = q__7.r * q__8.i + q__7.i *
1778 q__1.r = q__2.r - q__6.r, q__1.i = q__2.i -
1780 a[i__3].r = q__1.r, a[i__3].i = q__1.i;
1784 /* Store L(k) and L(k+1) in cols k and k+1 for row J */
1786 i__2 = j + k * a_dim1;
1787 q__1.r = wk.r / d__, q__1.i = wk.i / d__;
1788 a[i__2].r = q__1.r, a[i__2].i = q__1.i;
1789 i__2 = j + (k + 1) * a_dim1;
1790 q__1.r = wkp1.r / d__, q__1.i = wkp1.i / d__;
1791 a[i__2].r = q__1.r, a[i__2].i = q__1.i;
1792 /* (*) Make sure that diagonal element of pivot is real */
1793 i__2 = j + j * a_dim1;
1794 i__3 = j + j * a_dim1;
1796 q__1.r = r__1, q__1.i = 0.f;
1797 a[i__2].r = q__1.r, a[i__2].i = q__1.i;
1804 /* Copy subdiagonal elements of D(K) to E(K) and */
1805 /* ZERO out subdiagonal entry of A */
1808 i__2 = k + 1 + k * a_dim1;
1809 e[i__1].r = a[i__2].r, e[i__1].i = a[i__2].i;
1811 e[i__1].r = 0.f, e[i__1].i = 0.f;
1812 i__1 = k + 1 + k * a_dim1;
1813 a[i__1].r = 0.f, a[i__1].i = 0.f;
1817 /* End column K is nonsingular */
1821 /* Store details of the interchanges in IPIV */
1830 /* Increase K and return to the start of the main loop */
1842 /* End of CHETF2_RK */