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_n1 = -1;
517 /* > \brief \b DTRSEN */
519 /* =========== DOCUMENTATION =========== */
521 /* Online html documentation available at */
522 /* http://www.netlib.org/lapack/explore-html/ */
525 /* > Download DTRSEN + dependencies */
526 /* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dtrsen.
529 /* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dtrsen.
532 /* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dtrsen.
540 /* SUBROUTINE DTRSEN( JOB, COMPQ, SELECT, N, T, LDT, Q, LDQ, WR, WI, */
541 /* M, S, SEP, WORK, LWORK, IWORK, LIWORK, INFO ) */
543 /* CHARACTER COMPQ, JOB */
544 /* INTEGER INFO, LDQ, LDT, LIWORK, LWORK, M, N */
545 /* DOUBLE PRECISION S, SEP */
546 /* LOGICAL SELECT( * ) */
547 /* INTEGER IWORK( * ) */
548 /* DOUBLE PRECISION Q( LDQ, * ), T( LDT, * ), WI( * ), WORK( * ), */
552 /* > \par Purpose: */
557 /* > DTRSEN reorders the real Schur factorization of a real matrix */
558 /* > A = Q*T*Q**T, so that a selected cluster of eigenvalues appears in */
559 /* > the leading diagonal blocks of the upper quasi-triangular matrix T, */
560 /* > and the leading columns of Q form an orthonormal basis of the */
561 /* > corresponding right invariant subspace. */
563 /* > Optionally the routine computes the reciprocal condition numbers of */
564 /* > the cluster of eigenvalues and/or the invariant subspace. */
566 /* > T must be in Schur canonical form (as returned by DHSEQR), that is, */
567 /* > block upper triangular with 1-by-1 and 2-by-2 diagonal blocks; each */
568 /* > 2-by-2 diagonal block has its diagonal elements equal and its */
569 /* > off-diagonal elements of opposite sign. */
575 /* > \param[in] JOB */
577 /* > JOB is CHARACTER*1 */
578 /* > Specifies whether condition numbers are required for the */
579 /* > cluster of eigenvalues (S) or the invariant subspace (SEP): */
581 /* > = 'E': for eigenvalues only (S); */
582 /* > = 'V': for invariant subspace only (SEP); */
583 /* > = 'B': for both eigenvalues and invariant subspace (S and */
587 /* > \param[in] COMPQ */
589 /* > COMPQ is CHARACTER*1 */
590 /* > = 'V': update the matrix Q of Schur vectors; */
591 /* > = 'N': do not update Q. */
594 /* > \param[in] SELECT */
596 /* > SELECT is LOGICAL array, dimension (N) */
597 /* > SELECT specifies the eigenvalues in the selected cluster. To */
598 /* > select a real eigenvalue w(j), SELECT(j) must be set to */
599 /* > .TRUE.. To select a complex conjugate pair of eigenvalues */
600 /* > w(j) and w(j+1), corresponding to a 2-by-2 diagonal block, */
601 /* > either SELECT(j) or SELECT(j+1) or both must be set to */
602 /* > .TRUE.; a complex conjugate pair of eigenvalues must be */
603 /* > either both included in the cluster or both excluded. */
609 /* > The order of the matrix T. N >= 0. */
612 /* > \param[in,out] T */
614 /* > T is DOUBLE PRECISION array, dimension (LDT,N) */
615 /* > On entry, the upper quasi-triangular matrix T, in Schur */
616 /* > canonical form. */
617 /* > On exit, T is overwritten by the reordered matrix T, again in */
618 /* > Schur canonical form, with the selected eigenvalues in the */
619 /* > leading diagonal blocks. */
622 /* > \param[in] LDT */
624 /* > LDT is INTEGER */
625 /* > The leading dimension of the array T. LDT >= f2cmax(1,N). */
628 /* > \param[in,out] Q */
630 /* > Q is DOUBLE PRECISION array, dimension (LDQ,N) */
631 /* > On entry, if COMPQ = 'V', the matrix Q of Schur vectors. */
632 /* > On exit, if COMPQ = 'V', Q has been postmultiplied by the */
633 /* > orthogonal transformation matrix which reorders T; the */
634 /* > leading M columns of Q form an orthonormal basis for the */
635 /* > specified invariant subspace. */
636 /* > If COMPQ = 'N', Q is not referenced. */
639 /* > \param[in] LDQ */
641 /* > LDQ is INTEGER */
642 /* > The leading dimension of the array Q. */
643 /* > LDQ >= 1; and if COMPQ = 'V', LDQ >= N. */
646 /* > \param[out] WR */
648 /* > WR is DOUBLE PRECISION array, dimension (N) */
650 /* > \param[out] WI */
652 /* > WI is DOUBLE PRECISION array, dimension (N) */
654 /* > The real and imaginary parts, respectively, of the reordered */
655 /* > eigenvalues of T. The eigenvalues are stored in the same */
656 /* > order as on the diagonal of T, with WR(i) = T(i,i) and, if */
657 /* > T(i:i+1,i:i+1) is a 2-by-2 diagonal block, WI(i) > 0 and */
658 /* > WI(i+1) = -WI(i). Note that if a complex eigenvalue is */
659 /* > sufficiently ill-conditioned, then its value may differ */
660 /* > significantly from its value before reordering. */
663 /* > \param[out] M */
666 /* > The dimension of the specified invariant subspace. */
667 /* > 0 < = M <= N. */
670 /* > \param[out] S */
672 /* > S is DOUBLE PRECISION */
673 /* > If JOB = 'E' or 'B', S is a lower bound on the reciprocal */
674 /* > condition number for the selected cluster of eigenvalues. */
675 /* > S cannot underestimate the true reciprocal condition number */
676 /* > by more than a factor of sqrt(N). If M = 0 or N, S = 1. */
677 /* > If JOB = 'N' or 'V', S is not referenced. */
680 /* > \param[out] SEP */
682 /* > SEP is DOUBLE PRECISION */
683 /* > If JOB = 'V' or 'B', SEP is the estimated reciprocal */
684 /* > condition number of the specified invariant subspace. If */
685 /* > M = 0 or N, SEP = norm(T). */
686 /* > If JOB = 'N' or 'E', SEP is not referenced. */
689 /* > \param[out] WORK */
691 /* > WORK is DOUBLE PRECISION array, dimension (MAX(1,LWORK)) */
692 /* > On exit, if INFO = 0, WORK(1) returns the optimal LWORK. */
695 /* > \param[in] LWORK */
697 /* > LWORK is INTEGER */
698 /* > The dimension of the array WORK. */
699 /* > If JOB = 'N', LWORK >= f2cmax(1,N); */
700 /* > if JOB = 'E', LWORK >= f2cmax(1,M*(N-M)); */
701 /* > if JOB = 'V' or 'B', LWORK >= f2cmax(1,2*M*(N-M)). */
703 /* > If LWORK = -1, then a workspace query is assumed; the routine */
704 /* > only calculates the optimal size of the WORK array, returns */
705 /* > this value as the first entry of the WORK array, and no error */
706 /* > message related to LWORK is issued by XERBLA. */
709 /* > \param[out] IWORK */
711 /* > IWORK is INTEGER array, dimension (MAX(1,LIWORK)) */
712 /* > On exit, if INFO = 0, IWORK(1) returns the optimal LIWORK. */
715 /* > \param[in] LIWORK */
717 /* > LIWORK is INTEGER */
718 /* > The dimension of the array IWORK. */
719 /* > If JOB = 'N' or 'E', LIWORK >= 1; */
720 /* > if JOB = 'V' or 'B', LIWORK >= f2cmax(1,M*(N-M)). */
722 /* > If LIWORK = -1, then a workspace query is assumed; the */
723 /* > routine only calculates the optimal size of the IWORK array, */
724 /* > returns this value as the first entry of the IWORK array, and */
725 /* > no error message related to LIWORK is issued by XERBLA. */
728 /* > \param[out] INFO */
730 /* > INFO is INTEGER */
731 /* > = 0: successful exit */
732 /* > < 0: if INFO = -i, the i-th argument had an illegal value */
733 /* > = 1: reordering of T failed because some eigenvalues are too */
734 /* > close to separate (the problem is very ill-conditioned); */
735 /* > T may have been partially reordered, and WR and WI */
736 /* > contain the eigenvalues in the same order as in T; S and */
737 /* > SEP (if requested) are set to zero. */
743 /* > \author Univ. of Tennessee */
744 /* > \author Univ. of California Berkeley */
745 /* > \author Univ. of Colorado Denver */
746 /* > \author NAG Ltd. */
748 /* > \date April 2012 */
750 /* > \ingroup doubleOTHERcomputational */
752 /* > \par Further Details: */
753 /* ===================== */
757 /* > DTRSEN first collects the selected eigenvalues by computing an */
758 /* > orthogonal transformation Z to move them to the top left corner of T. */
759 /* > In other words, the selected eigenvalues are the eigenvalues of T11 */
762 /* > Z**T * T * Z = ( T11 T12 ) n1 */
766 /* > where N = n1+n2 and Z**T means the transpose of Z. The first n1 columns */
767 /* > of Z span the specified invariant subspace of T. */
769 /* > If T has been obtained from the real Schur factorization of a matrix */
770 /* > A = Q*T*Q**T, then the reordered real Schur factorization of A is given */
771 /* > by A = (Q*Z)*(Z**T*T*Z)*(Q*Z)**T, and the first n1 columns of Q*Z span */
772 /* > the corresponding invariant subspace of A. */
774 /* > The reciprocal condition number of the average of the eigenvalues of */
775 /* > T11 may be returned in S. S lies between 0 (very badly conditioned) */
776 /* > and 1 (very well conditioned). It is computed as follows. First we */
777 /* > compute R so that */
779 /* > P = ( I R ) n1 */
783 /* > is the projector on the invariant subspace associated with T11. */
784 /* > R is the solution of the Sylvester equation: */
786 /* > T11*R - R*T22 = T12. */
788 /* > Let F-norm(M) denote the Frobenius-norm of M and 2-norm(M) denote */
789 /* > the two-norm of M. Then S is computed as the lower bound */
791 /* > (1 + F-norm(R)**2)**(-1/2) */
793 /* > on the reciprocal of 2-norm(P), the true reciprocal condition number. */
794 /* > S cannot underestimate 1 / 2-norm(P) by more than a factor of */
797 /* > An approximate error bound for the computed average of the */
798 /* > eigenvalues of T11 is */
800 /* > EPS * norm(T) / S */
802 /* > where EPS is the machine precision. */
804 /* > The reciprocal condition number of the right invariant subspace */
805 /* > spanned by the first n1 columns of Z (or of Q*Z) is returned in SEP. */
806 /* > SEP is defined as the separation of T11 and T22: */
808 /* > sep( T11, T22 ) = sigma-f2cmin( C ) */
810 /* > where sigma-f2cmin(C) is the smallest singular value of the */
811 /* > n1*n2-by-n1*n2 matrix */
813 /* > C = kprod( I(n2), T11 ) - kprod( transpose(T22), I(n1) ) */
815 /* > I(m) is an m by m identity matrix, and kprod denotes the Kronecker */
816 /* > product. We estimate sigma-f2cmin(C) by the reciprocal of an estimate of */
817 /* > the 1-norm of inverse(C). The true reciprocal 1-norm of inverse(C) */
818 /* > cannot differ from sigma-f2cmin(C) by more than a factor of sqrt(n1*n2). */
820 /* > When SEP is small, small changes in T can cause large changes in */
821 /* > the invariant subspace. An approximate bound on the maximum angular */
822 /* > error in the computed right invariant subspace is */
824 /* > EPS * norm(T) / SEP */
827 /* ===================================================================== */
828 /* Subroutine */ int dtrsen_(char *job, char *compq, logical *select, integer
829 *n, doublereal *t, integer *ldt, doublereal *q, integer *ldq,
830 doublereal *wr, doublereal *wi, integer *m, doublereal *s, doublereal
831 *sep, doublereal *work, integer *lwork, integer *iwork, integer *
832 liwork, integer *info)
834 /* System generated locals */
835 integer q_dim1, q_offset, t_dim1, t_offset, i__1, i__2;
836 doublereal d__1, d__2;
838 /* Local variables */
845 extern logical lsame_(char *, char *);
846 integer isave[3], lwmin;
847 logical wantq, wants;
850 extern /* Subroutine */ int dlacn2_(integer *, doublereal *, doublereal *,
851 integer *, doublereal *, integer *, integer *);
853 extern doublereal dlange_(char *, integer *, integer *, doublereal *,
854 integer *, doublereal *);
856 extern /* Subroutine */ int dlacpy_(char *, integer *, integer *,
857 doublereal *, integer *, doublereal *, integer *),
858 xerbla_(char *, integer *, ftnlen);
860 extern /* Subroutine */ int dtrexc_(char *, integer *, doublereal *,
861 integer *, doublereal *, integer *, integer *, integer *,
862 doublereal *, integer *);
864 logical wantsp, lquery;
865 extern /* Subroutine */ int dtrsyl_(char *, char *, integer *, integer *,
866 integer *, doublereal *, integer *, doublereal *, integer *,
867 doublereal *, integer *, doublereal *, integer *);
871 /* -- LAPACK computational routine (version 3.7.0) -- */
872 /* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
873 /* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
877 /* ===================================================================== */
880 /* Decode and test the input parameters */
882 /* Parameter adjustments */
885 t_offset = 1 + t_dim1 * 1;
888 q_offset = 1 + q_dim1 * 1;
896 wantbh = lsame_(job, "B");
897 wants = lsame_(job, "E") || wantbh;
898 wantsp = lsame_(job, "V") || wantbh;
899 wantq = lsame_(compq, "V");
902 lquery = *lwork == -1;
903 if (! lsame_(job, "N") && ! wants && ! wantsp) {
905 } else if (! lsame_(compq, "N") && ! wantq) {
909 } else if (*ldt < f2cmax(1,*n)) {
911 } else if (*ldq < 1 || wantq && *ldq < *n) {
915 /* Set M to the dimension of the specified invariant subspace, */
916 /* and test LWORK and LIWORK. */
921 for (k = 1; k <= i__1; ++k) {
926 if (t[k + 1 + k * t_dim1] == 0.) {
932 if (select[k] || select[k + 1]) {
951 i__1 = 1, i__2 = nn << 1;
952 lwmin = f2cmax(i__1,i__2);
953 liwmin = f2cmax(1,nn);
954 } else if (lsame_(job, "N")) {
955 lwmin = f2cmax(1,*n);
957 } else if (lsame_(job, "E")) {
958 lwmin = f2cmax(1,nn);
962 if (*lwork < lwmin && ! lquery) {
964 } else if (*liwork < liwmin && ! lquery) {
970 work[1] = (doublereal) lwmin;
976 xerbla_("DTRSEN", &i__1, (ftnlen)6);
982 /* Quick return if possible. */
984 if (*m == *n || *m == 0) {
989 *sep = dlange_("1", n, n, &t[t_offset], ldt, &work[1]);
994 /* Collect the selected blocks at the top-left corner of T. */
999 for (k = 1; k <= i__1; ++k) {
1005 if (t[k + 1 + k * t_dim1] != 0.) {
1007 swap = swap || select[k + 1];
1013 /* Swap the K-th block to position KS. */
1018 dtrexc_(compq, n, &t[t_offset], ldt, &q[q_offset], ldq, &
1019 kk, &ks, &work[1], &ierr);
1021 if (ierr == 1 || ierr == 2) {
1023 /* Blocks too close to swap: exit. */
1044 /* Solve Sylvester equation for R: */
1046 /* T11*R - R*T22 = scale*T12 */
1048 dlacpy_("F", &n1, &n2, &t[(n1 + 1) * t_dim1 + 1], ldt, &work[1], &n1);
1049 dtrsyl_("N", "N", &c_n1, &n1, &n2, &t[t_offset], ldt, &t[n1 + 1 + (n1
1050 + 1) * t_dim1], ldt, &work[1], &n1, &scale, &ierr);
1052 /* Estimate the reciprocal of the condition number of the cluster */
1053 /* of eigenvalues. */
1055 rnorm = dlange_("F", &n1, &n2, &work[1], &n1, &work[1]);
1059 *s = scale / (sqrt(scale * scale / rnorm + rnorm) * sqrt(rnorm));
1065 /* Estimate sep(T11,T22). */
1070 dlacn2_(&nn, &work[nn + 1], &work[1], &iwork[1], &est, &kase, isave);
1074 /* Solve T11*R - R*T22 = scale*X. */
1076 dtrsyl_("N", "N", &c_n1, &n1, &n2, &t[t_offset], ldt, &t[n1 +
1077 1 + (n1 + 1) * t_dim1], ldt, &work[1], &n1, &scale, &
1081 /* Solve T11**T*R - R*T22**T = scale*X. */
1083 dtrsyl_("T", "T", &c_n1, &n1, &n2, &t[t_offset], ldt, &t[n1 +
1084 1 + (n1 + 1) * t_dim1], ldt, &work[1], &n1, &scale, &
1095 /* Store the output eigenvalues in WR and WI. */
1098 for (k = 1; k <= i__1; ++k) {
1099 wr[k] = t[k + k * t_dim1];
1104 for (k = 1; k <= i__1; ++k) {
1105 if (t[k + 1 + k * t_dim1] != 0.) {
1106 wi[k] = sqrt((d__1 = t[k + (k + 1) * t_dim1], abs(d__1))) * sqrt((
1107 d__2 = t[k + 1 + k * t_dim1], abs(d__2)));
1113 work[1] = (doublereal) lwmin;