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;
516 static integer c_n1 = -1;
517 static integer c__2 = 2;
518 static real c_b17 = 0.f;
519 static logical c_false = FALSE_;
520 static real c_b29 = 1.f;
521 static logical c_true = TRUE_;
523 /* > \brief \b STREVC3 */
525 /* =========== DOCUMENTATION =========== */
527 /* Online html documentation available at */
528 /* http://www.netlib.org/lapack/explore-html/ */
531 /* > Download STREVC3 + dependencies */
532 /* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/strevc3
535 /* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/strevc3
538 /* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/strevc3
546 /* SUBROUTINE STREVC3( SIDE, HOWMNY, SELECT, N, T, LDT, VL, LDVL, */
547 /* VR, LDVR, MM, M, WORK, LWORK, INFO ) */
549 /* CHARACTER HOWMNY, SIDE */
550 /* INTEGER INFO, LDT, LDVL, LDVR, LWORK, M, MM, N */
551 /* LOGICAL SELECT( * ) */
552 /* REAL T( LDT, * ), VL( LDVL, * ), VR( LDVR, * ), */
556 /* > \par Purpose: */
561 /* > STREVC3 computes some or all of the right and/or left eigenvectors of */
562 /* > a real upper quasi-triangular matrix T. */
563 /* > Matrices of this type are produced by the Schur factorization of */
564 /* > a real general matrix: A = Q*T*Q**T, as computed by SHSEQR. */
566 /* > The right eigenvector x and the left eigenvector y of T corresponding */
567 /* > to an eigenvalue w are defined by: */
569 /* > T*x = w*x, (y**T)*T = w*(y**T) */
571 /* > where y**T denotes the transpose of the vector y. */
572 /* > The eigenvalues are not input to this routine, but are read directly */
573 /* > from the diagonal blocks of T. */
575 /* > This routine returns the matrices X and/or Y of right and left */
576 /* > eigenvectors of T, or the products Q*X and/or Q*Y, where Q is an */
577 /* > input matrix. If Q is the orthogonal factor that reduces a matrix */
578 /* > A to Schur form T, then Q*X and Q*Y are the matrices of right and */
579 /* > left eigenvectors of A. */
581 /* > This uses a Level 3 BLAS version of the back transformation. */
587 /* > \param[in] SIDE */
589 /* > SIDE is CHARACTER*1 */
590 /* > = 'R': compute right eigenvectors only; */
591 /* > = 'L': compute left eigenvectors only; */
592 /* > = 'B': compute both right and left eigenvectors. */
595 /* > \param[in] HOWMNY */
597 /* > HOWMNY is CHARACTER*1 */
598 /* > = 'A': compute all right and/or left eigenvectors; */
599 /* > = 'B': compute all right and/or left eigenvectors, */
600 /* > backtransformed by the matrices in VR and/or VL; */
601 /* > = 'S': compute selected right and/or left eigenvectors, */
602 /* > as indicated by the logical array SELECT. */
605 /* > \param[in,out] SELECT */
607 /* > SELECT is LOGICAL array, dimension (N) */
608 /* > If HOWMNY = 'S', SELECT specifies the eigenvectors to be */
610 /* > If w(j) is a real eigenvalue, the corresponding real */
611 /* > eigenvector is computed if SELECT(j) is .TRUE.. */
612 /* > If w(j) and w(j+1) are the real and imaginary parts of a */
613 /* > complex eigenvalue, the corresponding complex eigenvector is */
614 /* > computed if either SELECT(j) or SELECT(j+1) is .TRUE., and */
615 /* > on exit SELECT(j) is set to .TRUE. and SELECT(j+1) is set to */
617 /* > Not referenced if HOWMNY = 'A' or 'B'. */
623 /* > The order of the matrix T. N >= 0. */
628 /* > T is REAL array, dimension (LDT,N) */
629 /* > The upper quasi-triangular matrix T in Schur canonical form. */
632 /* > \param[in] LDT */
634 /* > LDT is INTEGER */
635 /* > The leading dimension of the array T. LDT >= f2cmax(1,N). */
638 /* > \param[in,out] VL */
640 /* > VL is REAL array, dimension (LDVL,MM) */
641 /* > On entry, if SIDE = 'L' or 'B' and HOWMNY = 'B', VL must */
642 /* > contain an N-by-N matrix Q (usually the orthogonal matrix Q */
643 /* > of Schur vectors returned by SHSEQR). */
644 /* > On exit, if SIDE = 'L' or 'B', VL contains: */
645 /* > if HOWMNY = 'A', the matrix Y of left eigenvectors of T; */
646 /* > if HOWMNY = 'B', the matrix Q*Y; */
647 /* > if HOWMNY = 'S', the left eigenvectors of T specified by */
648 /* > SELECT, stored consecutively in the columns */
649 /* > of VL, in the same order as their */
651 /* > A complex eigenvector corresponding to a complex eigenvalue */
652 /* > is stored in two consecutive columns, the first holding the */
653 /* > real part, and the second the imaginary part. */
654 /* > Not referenced if SIDE = 'R'. */
657 /* > \param[in] LDVL */
659 /* > LDVL is INTEGER */
660 /* > The leading dimension of the array VL. */
661 /* > LDVL >= 1, and if SIDE = 'L' or 'B', LDVL >= N. */
664 /* > \param[in,out] VR */
666 /* > VR is REAL array, dimension (LDVR,MM) */
667 /* > On entry, if SIDE = 'R' or 'B' and HOWMNY = 'B', VR must */
668 /* > contain an N-by-N matrix Q (usually the orthogonal matrix Q */
669 /* > of Schur vectors returned by SHSEQR). */
670 /* > On exit, if SIDE = 'R' or 'B', VR contains: */
671 /* > if HOWMNY = 'A', the matrix X of right eigenvectors of T; */
672 /* > if HOWMNY = 'B', the matrix Q*X; */
673 /* > if HOWMNY = 'S', the right eigenvectors of T specified by */
674 /* > SELECT, stored consecutively in the columns */
675 /* > of VR, in the same order as their */
677 /* > A complex eigenvector corresponding to a complex eigenvalue */
678 /* > is stored in two consecutive columns, the first holding the */
679 /* > real part and the second the imaginary part. */
680 /* > Not referenced if SIDE = 'L'. */
683 /* > \param[in] LDVR */
685 /* > LDVR is INTEGER */
686 /* > The leading dimension of the array VR. */
687 /* > LDVR >= 1, and if SIDE = 'R' or 'B', LDVR >= N. */
690 /* > \param[in] MM */
692 /* > MM is INTEGER */
693 /* > The number of columns in the arrays VL and/or VR. MM >= M. */
696 /* > \param[out] M */
699 /* > The number of columns in the arrays VL and/or VR actually */
700 /* > used to store the eigenvectors. */
701 /* > If HOWMNY = 'A' or 'B', M is set to N. */
702 /* > Each selected real eigenvector occupies one column and each */
703 /* > selected complex eigenvector occupies two columns. */
706 /* > \param[out] WORK */
708 /* > WORK is REAL array, dimension (MAX(1,LWORK)) */
711 /* > \param[in] LWORK */
713 /* > LWORK is INTEGER */
714 /* > The dimension of array WORK. LWORK >= f2cmax(1,3*N). */
715 /* > For optimum performance, LWORK >= N + 2*N*NB, where NB is */
716 /* > the optimal blocksize. */
718 /* > If LWORK = -1, then a workspace query is assumed; the routine */
719 /* > only calculates the optimal size of the WORK array, returns */
720 /* > this value as the first entry of the WORK array, and no error */
721 /* > message related to LWORK is issued by XERBLA. */
724 /* > \param[out] INFO */
726 /* > INFO is INTEGER */
727 /* > = 0: successful exit */
728 /* > < 0: if INFO = -i, the i-th argument had an illegal value */
734 /* > \author Univ. of Tennessee */
735 /* > \author Univ. of California Berkeley */
736 /* > \author Univ. of Colorado Denver */
737 /* > \author NAG Ltd. */
739 /* > \date November 2017 */
741 /* @generated from dtrevc3.f, fortran d -> s, Tue Apr 19 01:47:44 2016 */
743 /* > \ingroup realOTHERcomputational */
745 /* > \par Further Details: */
746 /* ===================== */
750 /* > The algorithm used in this program is basically backward (forward) */
751 /* > substitution, with scaling to make the the code robust against */
752 /* > possible overflow. */
754 /* > Each eigenvector is normalized so that the element of largest */
755 /* > magnitude has magnitude 1; here the magnitude of a complex number */
756 /* > (x,y) is taken to be |x| + |y|. */
759 /* ===================================================================== */
760 /* Subroutine */ int strevc3_(char *side, char *howmny, logical *select,
761 integer *n, real *t, integer *ldt, real *vl, integer *ldvl, real *vr,
762 integer *ldvr, integer *mm, integer *m, real *work, integer *lwork,
765 /* System generated locals */
767 integer t_dim1, t_offset, vl_dim1, vl_offset, vr_dim1, vr_offset, i__1[2],
769 real r__1, r__2, r__3, r__4;
772 /* Local variables */
776 real unfl, ovfl, smin;
777 extern real sdot_(integer *, real *, integer *, real *, integer *);
780 integer jnxt, i__, j, k;
781 real scale, x[4] /* was [2][2] */;
782 extern logical lsame_(char *, char *);
783 extern /* Subroutine */ int sscal_(integer *, real *, real *, integer *),
784 sgemm_(char *, char *, integer *, integer *, integer *, real *,
785 real *, integer *, real *, integer *, real *, real *, integer *);
788 extern /* Subroutine */ int sgemv_(char *, integer *, integer *, real *,
789 real *, integer *, real *, integer *, real *, real *, integer *);
794 extern /* Subroutine */ int scopy_(integer *, real *, integer *, real *,
797 extern /* Subroutine */ int saxpy_(integer *, real *, real *, integer *,
799 integer iscomplex[128];
800 extern /* Subroutine */ int slaln2_(logical *, integer *, integer *, real
801 *, real *, real *, integer *, real *, real *, real *, integer *,
802 real *, real *, real *, integer *, real *, real *, integer *);
804 extern /* Subroutine */ int slabad_(real *, real *);
807 extern real slamch_(char *);
809 extern /* Subroutine */ int xerbla_(char *, integer *, ftnlen);
810 extern integer ilaenv_(integer *, char *, char *, integer *, integer *,
811 integer *, integer *, ftnlen, ftnlen);
813 extern integer isamax_(integer *, real *, integer *);
814 extern /* Subroutine */ int slacpy_(char *, integer *, integer *, real *,
815 integer *, real *, integer *), slaset_(char *, integer *,
816 integer *, real *, real *, real *, integer *);
824 /* -- LAPACK computational routine (version 3.8.0) -- */
825 /* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
826 /* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
830 /* ===================================================================== */
833 /* Decode and test the input parameters */
835 /* Parameter adjustments */
838 t_offset = 1 + t_dim1 * 1;
841 vl_offset = 1 + vl_dim1 * 1;
844 vr_offset = 1 + vr_dim1 * 1;
849 bothv = lsame_(side, "B");
850 rightv = lsame_(side, "R") || bothv;
851 leftv = lsame_(side, "L") || bothv;
853 allv = lsame_(howmny, "A");
854 over = lsame_(howmny, "B");
855 somev = lsame_(howmny, "S");
858 /* Writing concatenation */
859 i__1[0] = 1, a__1[0] = side;
860 i__1[1] = 1, a__1[1] = howmny;
861 s_cat(ch__1, a__1, i__1, &c__2, (ftnlen)2);
862 nb = ilaenv_(&c__1, "STREVC", ch__1, n, &c_n1, &c_n1, &c_n1, (ftnlen)6, (
864 maxwrk = *n + (*n << 1) * nb;
865 work[1] = (real) maxwrk;
866 lquery = *lwork == -1;
867 if (! rightv && ! leftv) {
869 } else if (! allv && ! over && ! somev) {
873 } else if (*ldt < f2cmax(1,*n)) {
875 } else if (*ldvl < 1 || leftv && *ldvl < *n) {
877 } else if (*ldvr < 1 || rightv && *ldvr < *n) {
879 } else /* if(complicated condition) */ {
881 i__2 = 1, i__3 = *n * 3;
882 if (*lwork < f2cmax(i__2,i__3) && ! lquery) {
886 /* Set M to the number of columns required to store the selected */
887 /* eigenvectors, standardize the array SELECT if necessary, and */
894 for (j = 1; j <= i__2; ++j) {
900 if (t[j + 1 + j * t_dim1] == 0.f) {
906 if (select[j] || select[j + 1]) {
930 xerbla_("STREVC3", &i__2, (ftnlen)7);
936 /* Quick return if possible. */
942 /* Use blocked version of back-transformation if sufficient workspace. */
943 /* Zero-out the workspace to avoid potential NaN propagation. */
945 if (over && *lwork >= *n + (*n << 4)) {
946 nb = (*lwork - *n) / (*n << 1);
948 i__2 = (nb << 1) + 1;
949 slaset_("F", n, &i__2, &c_b17, &c_b17, &work[1], n);
954 /* Set the constants to control overflow. */
956 unfl = slamch_("Safe minimum");
958 slabad_(&unfl, &ovfl);
959 ulp = slamch_("Precision");
960 smlnum = unfl * (*n / ulp);
961 bignum = (1.f - ulp) / smlnum;
963 /* Compute 1-norm of each column of strictly upper triangular */
964 /* part of T to control overflow in triangular solver. */
968 for (j = 2; j <= i__2; ++j) {
971 for (i__ = 1; i__ <= i__3; ++i__) {
972 work[j] += (r__1 = t[i__ + j * t_dim1], abs(r__1));
978 /* Index IP is used to specify the real or complex eigenvalue: */
979 /* IP = 0, real eigenvalue, */
980 /* 1, first of conjugate complex pair: (wr,wi) */
981 /* -1, second of conjugate complex pair: (wr,wi) */
982 /* ISCOMPLEX array stores IP for each column in current block. */
986 /* ============================================================ */
987 /* Compute right eigenvectors. */
989 /* IV is index of column in current block. */
990 /* For complex right vector, uses IV-1 for real part and IV for complex part. */
991 /* Non-blocked version always uses IV=2; */
992 /* blocked version starts with IV=NB, goes down to 1 or 2. */
993 /* (Note the "0-th" column is used for 1-norms computed above.) */
1000 for (ki = *n; ki >= 1; --ki) {
1002 /* previous iteration (ki+1) was second of conjugate pair, */
1003 /* so this ki is first of conjugate pair; skip to end of loop */
1006 } else if (ki == 1) {
1007 /* last column, so this ki must be real eigenvalue */
1009 } else if (t[ki + (ki - 1) * t_dim1] == 0.f) {
1010 /* zero on sub-diagonal, so this ki is real eigenvalue */
1013 /* non-zero on sub-diagonal, so this ki is second of conjugate pair */
1022 if (! select[ki - 1]) {
1028 /* Compute the KI-th eigenvalue (WR,WI). */
1030 wr = t[ki + ki * t_dim1];
1033 wi = sqrt((r__1 = t[ki + (ki - 1) * t_dim1], abs(r__1))) *
1034 sqrt((r__2 = t[ki - 1 + ki * t_dim1], abs(r__2)));
1037 r__1 = ulp * (abs(wr) + abs(wi));
1038 smin = f2cmax(r__1,smlnum);
1042 /* -------------------------------------------------------- */
1043 /* Real right eigenvector */
1045 work[ki + iv * *n] = 1.f;
1047 /* Form right-hand side. */
1050 for (k = 1; k <= i__2; ++k) {
1051 work[k + iv * *n] = -t[k + ki * t_dim1];
1055 /* Solve upper quasi-triangular system: */
1056 /* [ T(1:KI-1,1:KI-1) - WR ]*X = SCALE*WORK. */
1059 for (j = ki - 1; j >= 1; --j) {
1067 if (t[j + (j - 1) * t_dim1] != 0.f) {
1075 /* 1-by-1 diagonal block */
1077 slaln2_(&c_false, &c__1, &c__1, &smin, &c_b29, &t[j +
1078 j * t_dim1], ldt, &c_b29, &c_b29, &work[j +
1079 iv * *n], n, &wr, &c_b17, x, &c__2, &scale, &
1082 /* Scale X(1,1) to avoid overflow when updating */
1083 /* the right-hand side. */
1086 if (work[j] > bignum / xnorm) {
1092 /* Scale if necessary */
1095 sscal_(&ki, &scale, &work[iv * *n + 1], &c__1);
1097 work[j + iv * *n] = x[0];
1099 /* Update right-hand side */
1103 saxpy_(&i__2, &r__1, &t[j * t_dim1 + 1], &c__1, &work[
1104 iv * *n + 1], &c__1);
1108 /* 2-by-2 diagonal block */
1110 slaln2_(&c_false, &c__2, &c__1, &smin, &c_b29, &t[j -
1111 1 + (j - 1) * t_dim1], ldt, &c_b29, &c_b29, &
1112 work[j - 1 + iv * *n], n, &wr, &c_b17, x, &
1113 c__2, &scale, &xnorm, &ierr);
1115 /* Scale X(1,1) and X(2,1) to avoid overflow when */
1116 /* updating the right-hand side. */
1120 r__1 = work[j - 1], r__2 = work[j];
1121 beta = f2cmax(r__1,r__2);
1122 if (beta > bignum / xnorm) {
1129 /* Scale if necessary */
1132 sscal_(&ki, &scale, &work[iv * *n + 1], &c__1);
1134 work[j - 1 + iv * *n] = x[0];
1135 work[j + iv * *n] = x[1];
1137 /* Update right-hand side */
1141 saxpy_(&i__2, &r__1, &t[(j - 1) * t_dim1 + 1], &c__1,
1142 &work[iv * *n + 1], &c__1);
1145 saxpy_(&i__2, &r__1, &t[j * t_dim1 + 1], &c__1, &work[
1146 iv * *n + 1], &c__1);
1152 /* Copy the vector x or Q*x to VR and normalize. */
1155 /* ------------------------------ */
1156 /* no back-transform: copy x to VR and normalize. */
1157 scopy_(&ki, &work[iv * *n + 1], &c__1, &vr[is * vr_dim1 +
1160 ii = isamax_(&ki, &vr[is * vr_dim1 + 1], &c__1);
1161 remax = 1.f / (r__1 = vr[ii + is * vr_dim1], abs(r__1));
1162 sscal_(&ki, &remax, &vr[is * vr_dim1 + 1], &c__1);
1165 for (k = ki + 1; k <= i__2; ++k) {
1166 vr[k + is * vr_dim1] = 0.f;
1170 } else if (nb == 1) {
1171 /* ------------------------------ */
1172 /* version 1: back-transform each vector with GEMV, Q*x. */
1175 sgemv_("N", n, &i__2, &c_b29, &vr[vr_offset], ldvr, &
1176 work[iv * *n + 1], &c__1, &work[ki + iv * *n],
1177 &vr[ki * vr_dim1 + 1], &c__1);
1180 ii = isamax_(n, &vr[ki * vr_dim1 + 1], &c__1);
1181 remax = 1.f / (r__1 = vr[ii + ki * vr_dim1], abs(r__1));
1182 sscal_(n, &remax, &vr[ki * vr_dim1 + 1], &c__1);
1185 /* ------------------------------ */
1186 /* version 2: back-transform block of vectors with GEMM */
1187 /* zero out below vector */
1189 for (k = ki + 1; k <= i__2; ++k) {
1190 work[k + iv * *n] = 0.f;
1192 iscomplex[iv - 1] = ip;
1193 /* back-transform and normalization is done below */
1197 /* -------------------------------------------------------- */
1198 /* Complex right eigenvector. */
1201 /* [ ( T(KI-1,KI-1) T(KI-1,KI) ) - (WR + I*WI) ]*X = 0. */
1202 /* [ ( T(KI, KI-1) T(KI, KI) ) ] */
1204 if ((r__1 = t[ki - 1 + ki * t_dim1], abs(r__1)) >= (r__2 = t[
1205 ki + (ki - 1) * t_dim1], abs(r__2))) {
1206 work[ki - 1 + (iv - 1) * *n] = 1.f;
1207 work[ki + iv * *n] = wi / t[ki - 1 + ki * t_dim1];
1209 work[ki - 1 + (iv - 1) * *n] = -wi / t[ki + (ki - 1) *
1211 work[ki + iv * *n] = 1.f;
1213 work[ki + (iv - 1) * *n] = 0.f;
1214 work[ki - 1 + iv * *n] = 0.f;
1216 /* Form right-hand side. */
1219 for (k = 1; k <= i__2; ++k) {
1220 work[k + (iv - 1) * *n] = -work[ki - 1 + (iv - 1) * *n] *
1221 t[k + (ki - 1) * t_dim1];
1222 work[k + iv * *n] = -work[ki + iv * *n] * t[k + ki *
1227 /* Solve upper quasi-triangular system: */
1228 /* [ T(1:KI-2,1:KI-2) - (WR+i*WI) ]*X = SCALE*(WORK+i*WORK2) */
1231 for (j = ki - 2; j >= 1; --j) {
1239 if (t[j + (j - 1) * t_dim1] != 0.f) {
1247 /* 1-by-1 diagonal block */
1249 slaln2_(&c_false, &c__1, &c__2, &smin, &c_b29, &t[j +
1250 j * t_dim1], ldt, &c_b29, &c_b29, &work[j + (
1251 iv - 1) * *n], n, &wr, &wi, x, &c__2, &scale,
1254 /* Scale X(1,1) and X(1,2) to avoid overflow when */
1255 /* updating the right-hand side. */
1258 if (work[j] > bignum / xnorm) {
1265 /* Scale if necessary */
1268 sscal_(&ki, &scale, &work[(iv - 1) * *n + 1], &
1270 sscal_(&ki, &scale, &work[iv * *n + 1], &c__1);
1272 work[j + (iv - 1) * *n] = x[0];
1273 work[j + iv * *n] = x[2];
1275 /* Update the right-hand side */
1279 saxpy_(&i__2, &r__1, &t[j * t_dim1 + 1], &c__1, &work[
1280 (iv - 1) * *n + 1], &c__1);
1283 saxpy_(&i__2, &r__1, &t[j * t_dim1 + 1], &c__1, &work[
1284 iv * *n + 1], &c__1);
1288 /* 2-by-2 diagonal block */
1290 slaln2_(&c_false, &c__2, &c__2, &smin, &c_b29, &t[j -
1291 1 + (j - 1) * t_dim1], ldt, &c_b29, &c_b29, &
1292 work[j - 1 + (iv - 1) * *n], n, &wr, &wi, x, &
1293 c__2, &scale, &xnorm, &ierr);
1295 /* Scale X to avoid overflow when updating */
1296 /* the right-hand side. */
1300 r__1 = work[j - 1], r__2 = work[j];
1301 beta = f2cmax(r__1,r__2);
1302 if (beta > bignum / xnorm) {
1312 /* Scale if necessary */
1315 sscal_(&ki, &scale, &work[(iv - 1) * *n + 1], &
1317 sscal_(&ki, &scale, &work[iv * *n + 1], &c__1);
1319 work[j - 1 + (iv - 1) * *n] = x[0];
1320 work[j + (iv - 1) * *n] = x[1];
1321 work[j - 1 + iv * *n] = x[2];
1322 work[j + iv * *n] = x[3];
1324 /* Update the right-hand side */
1328 saxpy_(&i__2, &r__1, &t[(j - 1) * t_dim1 + 1], &c__1,
1329 &work[(iv - 1) * *n + 1], &c__1);
1332 saxpy_(&i__2, &r__1, &t[j * t_dim1 + 1], &c__1, &work[
1333 (iv - 1) * *n + 1], &c__1);
1336 saxpy_(&i__2, &r__1, &t[(j - 1) * t_dim1 + 1], &c__1,
1337 &work[iv * *n + 1], &c__1);
1340 saxpy_(&i__2, &r__1, &t[j * t_dim1 + 1], &c__1, &work[
1341 iv * *n + 1], &c__1);
1347 /* Copy the vector x or Q*x to VR and normalize. */
1350 /* ------------------------------ */
1351 /* no back-transform: copy x to VR and normalize. */
1352 scopy_(&ki, &work[(iv - 1) * *n + 1], &c__1, &vr[(is - 1)
1353 * vr_dim1 + 1], &c__1);
1354 scopy_(&ki, &work[iv * *n + 1], &c__1, &vr[is * vr_dim1 +
1359 for (k = 1; k <= i__2; ++k) {
1361 r__3 = emax, r__4 = (r__1 = vr[k + (is - 1) * vr_dim1]
1362 , abs(r__1)) + (r__2 = vr[k + is * vr_dim1],
1364 emax = f2cmax(r__3,r__4);
1368 sscal_(&ki, &remax, &vr[(is - 1) * vr_dim1 + 1], &c__1);
1369 sscal_(&ki, &remax, &vr[is * vr_dim1 + 1], &c__1);
1372 for (k = ki + 1; k <= i__2; ++k) {
1373 vr[k + (is - 1) * vr_dim1] = 0.f;
1374 vr[k + is * vr_dim1] = 0.f;
1378 } else if (nb == 1) {
1379 /* ------------------------------ */
1380 /* version 1: back-transform each vector with GEMV, Q*x. */
1383 sgemv_("N", n, &i__2, &c_b29, &vr[vr_offset], ldvr, &
1384 work[(iv - 1) * *n + 1], &c__1, &work[ki - 1
1385 + (iv - 1) * *n], &vr[(ki - 1) * vr_dim1 + 1],
1388 sgemv_("N", n, &i__2, &c_b29, &vr[vr_offset], ldvr, &
1389 work[iv * *n + 1], &c__1, &work[ki + iv * *n],
1390 &vr[ki * vr_dim1 + 1], &c__1);
1392 sscal_(n, &work[ki - 1 + (iv - 1) * *n], &vr[(ki - 1)
1393 * vr_dim1 + 1], &c__1);
1394 sscal_(n, &work[ki + iv * *n], &vr[ki * vr_dim1 + 1],
1400 for (k = 1; k <= i__2; ++k) {
1402 r__3 = emax, r__4 = (r__1 = vr[k + (ki - 1) * vr_dim1]
1403 , abs(r__1)) + (r__2 = vr[k + ki * vr_dim1],
1405 emax = f2cmax(r__3,r__4);
1409 sscal_(n, &remax, &vr[(ki - 1) * vr_dim1 + 1], &c__1);
1410 sscal_(n, &remax, &vr[ki * vr_dim1 + 1], &c__1);
1413 /* ------------------------------ */
1414 /* version 2: back-transform block of vectors with GEMM */
1415 /* zero out below vector */
1417 for (k = ki + 1; k <= i__2; ++k) {
1418 work[k + (iv - 1) * *n] = 0.f;
1419 work[k + iv * *n] = 0.f;
1421 iscomplex[iv - 2] = -ip;
1422 iscomplex[iv - 1] = ip;
1424 /* back-transform and normalization is done below */
1428 /* -------------------------------------------------------- */
1429 /* Blocked version of back-transform */
1430 /* For complex case, KI2 includes both vectors (KI-1 and KI) */
1436 /* Columns IV:NB of work are valid vectors. */
1437 /* When the number of vectors stored reaches NB-1 or NB, */
1438 /* or if this was last vector, do the GEMM */
1439 if (iv <= 2 || ki2 == 1) {
1441 i__3 = ki2 + nb - iv;
1442 sgemm_("N", "N", n, &i__2, &i__3, &c_b29, &vr[vr_offset],
1443 ldvr, &work[iv * *n + 1], n, &c_b17, &work[(nb +
1445 /* normalize vectors */
1447 for (k = iv; k <= i__2; ++k) {
1448 if (iscomplex[k - 1] == 0) {
1449 /* real eigenvector */
1450 ii = isamax_(n, &work[(nb + k) * *n + 1], &c__1);
1451 remax = 1.f / (r__1 = work[ii + (nb + k) * *n],
1453 } else if (iscomplex[k - 1] == 1) {
1454 /* first eigenvector of conjugate pair */
1457 for (ii = 1; ii <= i__3; ++ii) {
1459 r__3 = emax, r__4 = (r__1 = work[ii + (nb + k)
1460 * *n], abs(r__1)) + (r__2 = work[ii
1461 + (nb + k + 1) * *n], abs(r__2));
1462 emax = f2cmax(r__3,r__4);
1465 /* else if ISCOMPLEX(K).EQ.-1 */
1466 /* second eigenvector of conjugate pair */
1467 /* reuse same REMAX as previous K */
1469 sscal_(n, &remax, &work[(nb + k) * *n + 1], &c__1);
1472 slacpy_("F", n, &i__2, &work[(nb + iv) * *n + 1], n, &vr[
1473 ki2 * vr_dim1 + 1], ldvr);
1480 /* blocked back-transform */
1491 /* ============================================================ */
1492 /* Compute left eigenvectors. */
1494 /* IV is index of column in current block. */
1495 /* For complex left vector, uses IV for real part and IV+1 for complex part. */
1496 /* Non-blocked version always uses IV=1; */
1497 /* blocked version starts with IV=1, goes up to NB-1 or NB. */
1498 /* (Note the "0-th" column is used for 1-norms computed above.) */
1503 for (ki = 1; ki <= i__2; ++ki) {
1505 /* previous iteration (ki-1) was first of conjugate pair, */
1506 /* so this ki is second of conjugate pair; skip to end of loop */
1509 } else if (ki == *n) {
1510 /* last column, so this ki must be real eigenvalue */
1512 } else if (t[ki + 1 + ki * t_dim1] == 0.f) {
1513 /* zero on sub-diagonal, so this ki is real eigenvalue */
1516 /* non-zero on sub-diagonal, so this ki is first of conjugate pair */
1526 /* Compute the KI-th eigenvalue (WR,WI). */
1528 wr = t[ki + ki * t_dim1];
1531 wi = sqrt((r__1 = t[ki + (ki + 1) * t_dim1], abs(r__1))) *
1532 sqrt((r__2 = t[ki + 1 + ki * t_dim1], abs(r__2)));
1535 r__1 = ulp * (abs(wr) + abs(wi));
1536 smin = f2cmax(r__1,smlnum);
1540 /* -------------------------------------------------------- */
1541 /* Real left eigenvector */
1543 work[ki + iv * *n] = 1.f;
1545 /* Form right-hand side. */
1548 for (k = ki + 1; k <= i__3; ++k) {
1549 work[k + iv * *n] = -t[ki + k * t_dim1];
1553 /* Solve transposed quasi-triangular system: */
1554 /* [ T(KI+1:N,KI+1:N) - WR ]**T * X = SCALE*WORK */
1561 for (j = ki + 1; j <= i__3; ++j) {
1569 if (t[j + 1 + j * t_dim1] != 0.f) {
1577 /* 1-by-1 diagonal block */
1579 /* Scale if necessary to avoid overflow when forming */
1580 /* the right-hand side. */
1582 if (work[j] > vcrit) {
1585 sscal_(&i__4, &rec, &work[ki + iv * *n], &c__1);
1591 work[j + iv * *n] -= sdot_(&i__4, &t[ki + 1 + j *
1592 t_dim1], &c__1, &work[ki + 1 + iv * *n], &
1595 /* Solve [ T(J,J) - WR ]**T * X = WORK */
1597 slaln2_(&c_false, &c__1, &c__1, &smin, &c_b29, &t[j +
1598 j * t_dim1], ldt, &c_b29, &c_b29, &work[j +
1599 iv * *n], n, &wr, &c_b17, x, &c__2, &scale, &
1602 /* Scale if necessary */
1606 sscal_(&i__4, &scale, &work[ki + iv * *n], &c__1);
1608 work[j + iv * *n] = x[0];
1610 r__2 = (r__1 = work[j + iv * *n], abs(r__1));
1611 vmax = f2cmax(r__2,vmax);
1612 vcrit = bignum / vmax;
1616 /* 2-by-2 diagonal block */
1618 /* Scale if necessary to avoid overflow when forming */
1619 /* the right-hand side. */
1622 r__1 = work[j], r__2 = work[j + 1];
1623 beta = f2cmax(r__1,r__2);
1627 sscal_(&i__4, &rec, &work[ki + iv * *n], &c__1);
1633 work[j + iv * *n] -= sdot_(&i__4, &t[ki + 1 + j *
1634 t_dim1], &c__1, &work[ki + 1 + iv * *n], &
1638 work[j + 1 + iv * *n] -= sdot_(&i__4, &t[ki + 1 + (j
1639 + 1) * t_dim1], &c__1, &work[ki + 1 + iv * *n]
1643 /* [ T(J,J)-WR T(J,J+1) ]**T * X = SCALE*( WORK1 ) */
1644 /* [ T(J+1,J) T(J+1,J+1)-WR ] ( WORK2 ) */
1646 slaln2_(&c_true, &c__2, &c__1, &smin, &c_b29, &t[j +
1647 j * t_dim1], ldt, &c_b29, &c_b29, &work[j +
1648 iv * *n], n, &wr, &c_b17, x, &c__2, &scale, &
1651 /* Scale if necessary */
1655 sscal_(&i__4, &scale, &work[ki + iv * *n], &c__1);
1657 work[j + iv * *n] = x[0];
1658 work[j + 1 + iv * *n] = x[1];
1661 r__3 = (r__1 = work[j + iv * *n], abs(r__1)), r__4 = (
1662 r__2 = work[j + 1 + iv * *n], abs(r__2)),
1663 r__3 = f2cmax(r__3,r__4);
1664 vmax = f2cmax(r__3,vmax);
1665 vcrit = bignum / vmax;
1672 /* Copy the vector x or Q*x to VL and normalize. */
1675 /* ------------------------------ */
1676 /* no back-transform: copy x to VL and normalize. */
1678 scopy_(&i__3, &work[ki + iv * *n], &c__1, &vl[ki + is *
1682 ii = isamax_(&i__3, &vl[ki + is * vl_dim1], &c__1) + ki -
1684 remax = 1.f / (r__1 = vl[ii + is * vl_dim1], abs(r__1));
1686 sscal_(&i__3, &remax, &vl[ki + is * vl_dim1], &c__1);
1689 for (k = 1; k <= i__3; ++k) {
1690 vl[k + is * vl_dim1] = 0.f;
1694 } else if (nb == 1) {
1695 /* ------------------------------ */
1696 /* version 1: back-transform each vector with GEMV, Q*x. */
1699 sgemv_("N", n, &i__3, &c_b29, &vl[(ki + 1) * vl_dim1
1700 + 1], ldvl, &work[ki + 1 + iv * *n], &c__1, &
1701 work[ki + iv * *n], &vl[ki * vl_dim1 + 1], &
1705 ii = isamax_(n, &vl[ki * vl_dim1 + 1], &c__1);
1706 remax = 1.f / (r__1 = vl[ii + ki * vl_dim1], abs(r__1));
1707 sscal_(n, &remax, &vl[ki * vl_dim1 + 1], &c__1);
1710 /* ------------------------------ */
1711 /* version 2: back-transform block of vectors with GEMM */
1712 /* zero out above vector */
1713 /* could go from KI-NV+1 to KI-1 */
1715 for (k = 1; k <= i__3; ++k) {
1716 work[k + iv * *n] = 0.f;
1718 iscomplex[iv - 1] = ip;
1719 /* back-transform and normalization is done below */
1723 /* -------------------------------------------------------- */
1724 /* Complex left eigenvector. */
1726 /* Initial solve: */
1727 /* [ ( T(KI,KI) T(KI,KI+1) )**T - (WR - I* WI) ]*X = 0. */
1728 /* [ ( T(KI+1,KI) T(KI+1,KI+1) ) ] */
1730 if ((r__1 = t[ki + (ki + 1) * t_dim1], abs(r__1)) >= (r__2 =
1731 t[ki + 1 + ki * t_dim1], abs(r__2))) {
1732 work[ki + iv * *n] = wi / t[ki + (ki + 1) * t_dim1];
1733 work[ki + 1 + (iv + 1) * *n] = 1.f;
1735 work[ki + iv * *n] = 1.f;
1736 work[ki + 1 + (iv + 1) * *n] = -wi / t[ki + 1 + ki *
1739 work[ki + 1 + iv * *n] = 0.f;
1740 work[ki + (iv + 1) * *n] = 0.f;
1742 /* Form right-hand side. */
1745 for (k = ki + 2; k <= i__3; ++k) {
1746 work[k + iv * *n] = -work[ki + iv * *n] * t[ki + k *
1748 work[k + (iv + 1) * *n] = -work[ki + 1 + (iv + 1) * *n] *
1749 t[ki + 1 + k * t_dim1];
1753 /* Solve transposed quasi-triangular system: */
1754 /* [ T(KI+2:N,KI+2:N)**T - (WR-i*WI) ]*X = WORK1+i*WORK2 */
1761 for (j = ki + 2; j <= i__3; ++j) {
1769 if (t[j + 1 + j * t_dim1] != 0.f) {
1777 /* 1-by-1 diagonal block */
1779 /* Scale if necessary to avoid overflow when */
1780 /* forming the right-hand side elements. */
1782 if (work[j] > vcrit) {
1785 sscal_(&i__4, &rec, &work[ki + iv * *n], &c__1);
1787 sscal_(&i__4, &rec, &work[ki + (iv + 1) * *n], &
1794 work[j + iv * *n] -= sdot_(&i__4, &t[ki + 2 + j *
1795 t_dim1], &c__1, &work[ki + 2 + iv * *n], &
1798 work[j + (iv + 1) * *n] -= sdot_(&i__4, &t[ki + 2 + j
1799 * t_dim1], &c__1, &work[ki + 2 + (iv + 1) * *
1802 /* Solve [ T(J,J)-(WR-i*WI) ]*(X11+i*X12)= WK+I*WK2 */
1805 slaln2_(&c_false, &c__1, &c__2, &smin, &c_b29, &t[j +
1806 j * t_dim1], ldt, &c_b29, &c_b29, &work[j +
1807 iv * *n], n, &wr, &r__1, x, &c__2, &scale, &
1810 /* Scale if necessary */
1814 sscal_(&i__4, &scale, &work[ki + iv * *n], &c__1);
1816 sscal_(&i__4, &scale, &work[ki + (iv + 1) * *n], &
1819 work[j + iv * *n] = x[0];
1820 work[j + (iv + 1) * *n] = x[2];
1822 r__3 = (r__1 = work[j + iv * *n], abs(r__1)), r__4 = (
1823 r__2 = work[j + (iv + 1) * *n], abs(r__2)),
1824 r__3 = f2cmax(r__3,r__4);
1825 vmax = f2cmax(r__3,vmax);
1826 vcrit = bignum / vmax;
1830 /* 2-by-2 diagonal block */
1832 /* Scale if necessary to avoid overflow when forming */
1833 /* the right-hand side elements. */
1836 r__1 = work[j], r__2 = work[j + 1];
1837 beta = f2cmax(r__1,r__2);
1841 sscal_(&i__4, &rec, &work[ki + iv * *n], &c__1);
1843 sscal_(&i__4, &rec, &work[ki + (iv + 1) * *n], &
1850 work[j + iv * *n] -= sdot_(&i__4, &t[ki + 2 + j *
1851 t_dim1], &c__1, &work[ki + 2 + iv * *n], &
1855 work[j + (iv + 1) * *n] -= sdot_(&i__4, &t[ki + 2 + j
1856 * t_dim1], &c__1, &work[ki + 2 + (iv + 1) * *
1860 work[j + 1 + iv * *n] -= sdot_(&i__4, &t[ki + 2 + (j
1861 + 1) * t_dim1], &c__1, &work[ki + 2 + iv * *n]
1865 work[j + 1 + (iv + 1) * *n] -= sdot_(&i__4, &t[ki + 2
1866 + (j + 1) * t_dim1], &c__1, &work[ki + 2 + (
1867 iv + 1) * *n], &c__1);
1869 /* Solve 2-by-2 complex linear equation */
1870 /* [ (T(j,j) T(j,j+1) )**T - (wr-i*wi)*I ]*X = SCALE*B */
1871 /* [ (T(j+1,j) T(j+1,j+1)) ] */
1874 slaln2_(&c_true, &c__2, &c__2, &smin, &c_b29, &t[j +
1875 j * t_dim1], ldt, &c_b29, &c_b29, &work[j +
1876 iv * *n], n, &wr, &r__1, x, &c__2, &scale, &
1879 /* Scale if necessary */
1883 sscal_(&i__4, &scale, &work[ki + iv * *n], &c__1);
1885 sscal_(&i__4, &scale, &work[ki + (iv + 1) * *n], &
1888 work[j + iv * *n] = x[0];
1889 work[j + (iv + 1) * *n] = x[2];
1890 work[j + 1 + iv * *n] = x[1];
1891 work[j + 1 + (iv + 1) * *n] = x[3];
1893 r__1 = abs(x[0]), r__2 = abs(x[2]), r__1 = f2cmax(r__1,
1894 r__2), r__2 = abs(x[1]), r__1 = f2cmax(r__1,r__2)
1895 , r__2 = abs(x[3]), r__1 = f2cmax(r__1,r__2);
1896 vmax = f2cmax(r__1,vmax);
1897 vcrit = bignum / vmax;
1904 /* Copy the vector x or Q*x to VL and normalize. */
1907 /* ------------------------------ */
1908 /* no back-transform: copy x to VL and normalize. */
1910 scopy_(&i__3, &work[ki + iv * *n], &c__1, &vl[ki + is *
1913 scopy_(&i__3, &work[ki + (iv + 1) * *n], &c__1, &vl[ki + (
1914 is + 1) * vl_dim1], &c__1);
1918 for (k = ki; k <= i__3; ++k) {
1920 r__3 = emax, r__4 = (r__1 = vl[k + is * vl_dim1], abs(
1921 r__1)) + (r__2 = vl[k + (is + 1) * vl_dim1],
1923 emax = f2cmax(r__3,r__4);
1928 sscal_(&i__3, &remax, &vl[ki + is * vl_dim1], &c__1);
1930 sscal_(&i__3, &remax, &vl[ki + (is + 1) * vl_dim1], &c__1)
1934 for (k = 1; k <= i__3; ++k) {
1935 vl[k + is * vl_dim1] = 0.f;
1936 vl[k + (is + 1) * vl_dim1] = 0.f;
1940 } else if (nb == 1) {
1941 /* ------------------------------ */
1942 /* version 1: back-transform each vector with GEMV, Q*x. */
1945 sgemv_("N", n, &i__3, &c_b29, &vl[(ki + 2) * vl_dim1
1946 + 1], ldvl, &work[ki + 2 + iv * *n], &c__1, &
1947 work[ki + iv * *n], &vl[ki * vl_dim1 + 1], &
1950 sgemv_("N", n, &i__3, &c_b29, &vl[(ki + 2) * vl_dim1
1951 + 1], ldvl, &work[ki + 2 + (iv + 1) * *n], &
1952 c__1, &work[ki + 1 + (iv + 1) * *n], &vl[(ki
1953 + 1) * vl_dim1 + 1], &c__1);
1955 sscal_(n, &work[ki + iv * *n], &vl[ki * vl_dim1 + 1],
1957 sscal_(n, &work[ki + 1 + (iv + 1) * *n], &vl[(ki + 1)
1958 * vl_dim1 + 1], &c__1);
1963 for (k = 1; k <= i__3; ++k) {
1965 r__3 = emax, r__4 = (r__1 = vl[k + ki * vl_dim1], abs(
1966 r__1)) + (r__2 = vl[k + (ki + 1) * vl_dim1],
1968 emax = f2cmax(r__3,r__4);
1972 sscal_(n, &remax, &vl[ki * vl_dim1 + 1], &c__1);
1973 sscal_(n, &remax, &vl[(ki + 1) * vl_dim1 + 1], &c__1);
1976 /* ------------------------------ */
1977 /* version 2: back-transform block of vectors with GEMM */
1978 /* zero out above vector */
1979 /* could go from KI-NV+1 to KI-1 */
1981 for (k = 1; k <= i__3; ++k) {
1982 work[k + iv * *n] = 0.f;
1983 work[k + (iv + 1) * *n] = 0.f;
1985 iscomplex[iv - 1] = ip;
1986 iscomplex[iv] = -ip;
1988 /* back-transform and normalization is done below */
1992 /* -------------------------------------------------------- */
1993 /* Blocked version of back-transform */
1994 /* For complex case, KI2 includes both vectors (KI and KI+1) */
2000 /* Columns 1:IV of work are valid vectors. */
2001 /* When the number of vectors stored reaches NB-1 or NB, */
2002 /* or if this was last vector, do the GEMM */
2003 if (iv >= nb - 1 || ki2 == *n) {
2004 i__3 = *n - ki2 + iv;
2005 sgemm_("N", "N", n, &iv, &i__3, &c_b29, &vl[(ki2 - iv + 1)
2006 * vl_dim1 + 1], ldvl, &work[ki2 - iv + 1 + *n],
2007 n, &c_b17, &work[(nb + 1) * *n + 1], n);
2008 /* normalize vectors */
2010 for (k = 1; k <= i__3; ++k) {
2011 if (iscomplex[k - 1] == 0) {
2012 /* real eigenvector */
2013 ii = isamax_(n, &work[(nb + k) * *n + 1], &c__1);
2014 remax = 1.f / (r__1 = work[ii + (nb + k) * *n],
2016 } else if (iscomplex[k - 1] == 1) {
2017 /* first eigenvector of conjugate pair */
2020 for (ii = 1; ii <= i__4; ++ii) {
2022 r__3 = emax, r__4 = (r__1 = work[ii + (nb + k)
2023 * *n], abs(r__1)) + (r__2 = work[ii
2024 + (nb + k + 1) * *n], abs(r__2));
2025 emax = f2cmax(r__3,r__4);
2028 /* else if ISCOMPLEX(K).EQ.-1 */
2029 /* second eigenvector of conjugate pair */
2030 /* reuse same REMAX as previous K */
2032 sscal_(n, &remax, &work[(nb + k) * *n + 1], &c__1);
2034 slacpy_("F", n, &iv, &work[(nb + 1) * *n + 1], n, &vl[(
2035 ki2 - iv + 1) * vl_dim1 + 1], ldvl);
2042 /* blocked back-transform */
2054 /* End of STREVC3 */