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> DSTEVX computes the eigenvalues and, optionally, the left and/or right eigenvectors for OTHER
520 /* =========== DOCUMENTATION =========== */
522 /* Online html documentation available at */
523 /* http://www.netlib.org/lapack/explore-html/ */
526 /* > Download DSTEVX + dependencies */
527 /* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dstevx.
530 /* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dstevx.
533 /* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dstevx.
541 /* SUBROUTINE DSTEVX( JOBZ, RANGE, N, D, E, VL, VU, IL, IU, ABSTOL, */
542 /* M, W, Z, LDZ, WORK, IWORK, IFAIL, INFO ) */
544 /* CHARACTER JOBZ, RANGE */
545 /* INTEGER IL, INFO, IU, LDZ, M, N */
546 /* DOUBLE PRECISION ABSTOL, VL, VU */
547 /* INTEGER IFAIL( * ), IWORK( * ) */
548 /* DOUBLE PRECISION D( * ), E( * ), W( * ), WORK( * ), Z( LDZ, * ) */
551 /* > \par Purpose: */
556 /* > DSTEVX computes selected eigenvalues and, optionally, eigenvectors */
557 /* > of a real symmetric tridiagonal matrix A. Eigenvalues and */
558 /* > eigenvectors can be selected by specifying either a range of values */
559 /* > or a range of indices for the desired eigenvalues. */
565 /* > \param[in] JOBZ */
567 /* > JOBZ is CHARACTER*1 */
568 /* > = 'N': Compute eigenvalues only; */
569 /* > = 'V': Compute eigenvalues and eigenvectors. */
572 /* > \param[in] RANGE */
574 /* > RANGE is CHARACTER*1 */
575 /* > = 'A': all eigenvalues will be found. */
576 /* > = 'V': all eigenvalues in the half-open interval (VL,VU] */
577 /* > will be found. */
578 /* > = 'I': the IL-th through IU-th eigenvalues will be found. */
584 /* > The order of the matrix. N >= 0. */
587 /* > \param[in,out] D */
589 /* > D is DOUBLE PRECISION array, dimension (N) */
590 /* > On entry, the n diagonal elements of the tridiagonal matrix */
592 /* > On exit, D may be multiplied by a constant factor chosen */
593 /* > to avoid over/underflow in computing the eigenvalues. */
596 /* > \param[in,out] E */
598 /* > E is DOUBLE PRECISION array, dimension (f2cmax(1,N-1)) */
599 /* > On entry, the (n-1) subdiagonal elements of the tridiagonal */
600 /* > matrix A in elements 1 to N-1 of E. */
601 /* > On exit, E may be multiplied by a constant factor chosen */
602 /* > to avoid over/underflow in computing the eigenvalues. */
605 /* > \param[in] VL */
607 /* > VL is DOUBLE PRECISION */
608 /* > If RANGE='V', the lower bound of the interval to */
609 /* > be searched for eigenvalues. VL < VU. */
610 /* > Not referenced if RANGE = 'A' or 'I'. */
613 /* > \param[in] VU */
615 /* > VU is DOUBLE PRECISION */
616 /* > If RANGE='V', the upper bound of the interval to */
617 /* > be searched for eigenvalues. VL < VU. */
618 /* > Not referenced if RANGE = 'A' or 'I'. */
621 /* > \param[in] IL */
623 /* > IL is INTEGER */
624 /* > If RANGE='I', the index of the */
625 /* > smallest eigenvalue to be returned. */
626 /* > 1 <= IL <= IU <= N, if N > 0; IL = 1 and IU = 0 if N = 0. */
627 /* > Not referenced if RANGE = 'A' or 'V'. */
630 /* > \param[in] IU */
632 /* > IU is INTEGER */
633 /* > If RANGE='I', the index of the */
634 /* > largest eigenvalue to be returned. */
635 /* > 1 <= IL <= IU <= N, if N > 0; IL = 1 and IU = 0 if N = 0. */
636 /* > Not referenced if RANGE = 'A' or 'V'. */
639 /* > \param[in] ABSTOL */
641 /* > ABSTOL is DOUBLE PRECISION */
642 /* > The absolute error tolerance for the eigenvalues. */
643 /* > An approximate eigenvalue is accepted as converged */
644 /* > when it is determined to lie in an interval [a,b] */
645 /* > of width less than or equal to */
647 /* > ABSTOL + EPS * f2cmax( |a|,|b| ) , */
649 /* > where EPS is the machine precision. If ABSTOL is less */
650 /* > than or equal to zero, then EPS*|T| will be used in */
651 /* > its place, where |T| is the 1-norm of the tridiagonal */
654 /* > Eigenvalues will be computed most accurately when ABSTOL is */
655 /* > set to twice the underflow threshold 2*DLAMCH('S'), not zero. */
656 /* > If this routine returns with INFO>0, indicating that some */
657 /* > eigenvectors did not converge, try setting ABSTOL to */
658 /* > 2*DLAMCH('S'). */
660 /* > See "Computing Small Singular Values of Bidiagonal Matrices */
661 /* > with Guaranteed High Relative Accuracy," by Demmel and */
662 /* > Kahan, LAPACK Working Note #3. */
665 /* > \param[out] M */
668 /* > The total number of eigenvalues found. 0 <= M <= N. */
669 /* > If RANGE = 'A', M = N, and if RANGE = 'I', M = IU-IL+1. */
672 /* > \param[out] W */
674 /* > W is DOUBLE PRECISION array, dimension (N) */
675 /* > The first M elements contain the selected eigenvalues in */
676 /* > ascending order. */
679 /* > \param[out] Z */
681 /* > Z is DOUBLE PRECISION array, dimension (LDZ, f2cmax(1,M) ) */
682 /* > If JOBZ = 'V', then if INFO = 0, the first M columns of Z */
683 /* > contain the orthonormal eigenvectors of the matrix A */
684 /* > corresponding to the selected eigenvalues, with the i-th */
685 /* > column of Z holding the eigenvector associated with W(i). */
686 /* > If an eigenvector fails to converge (INFO > 0), then that */
687 /* > column of Z contains the latest approximation to the */
688 /* > eigenvector, and the index of the eigenvector is returned */
689 /* > in IFAIL. If JOBZ = 'N', then Z is not referenced. */
690 /* > Note: the user must ensure that at least f2cmax(1,M) columns are */
691 /* > supplied in the array Z; if RANGE = 'V', the exact value of M */
692 /* > is not known in advance and an upper bound must be used. */
695 /* > \param[in] LDZ */
697 /* > LDZ is INTEGER */
698 /* > The leading dimension of the array Z. LDZ >= 1, and if */
699 /* > JOBZ = 'V', LDZ >= f2cmax(1,N). */
702 /* > \param[out] WORK */
704 /* > WORK is DOUBLE PRECISION array, dimension (5*N) */
707 /* > \param[out] IWORK */
709 /* > IWORK is INTEGER array, dimension (5*N) */
712 /* > \param[out] IFAIL */
714 /* > IFAIL is INTEGER array, dimension (N) */
715 /* > If JOBZ = 'V', then if INFO = 0, the first M elements of */
716 /* > IFAIL are zero. If INFO > 0, then IFAIL contains the */
717 /* > indices of the eigenvectors that failed to converge. */
718 /* > If JOBZ = 'N', then IFAIL is not referenced. */
721 /* > \param[out] INFO */
723 /* > INFO is INTEGER */
724 /* > = 0: successful exit */
725 /* > < 0: if INFO = -i, the i-th argument had an illegal value */
726 /* > > 0: if INFO = i, then i eigenvectors failed to converge. */
727 /* > Their indices are stored in array IFAIL. */
733 /* > \author Univ. of Tennessee */
734 /* > \author Univ. of California Berkeley */
735 /* > \author Univ. of Colorado Denver */
736 /* > \author NAG Ltd. */
738 /* > \date June 2016 */
740 /* > \ingroup doubleOTHEReigen */
742 /* ===================================================================== */
743 /* Subroutine */ int dstevx_(char *jobz, char *range, integer *n, doublereal *
744 d__, doublereal *e, doublereal *vl, doublereal *vu, integer *il,
745 integer *iu, doublereal *abstol, integer *m, doublereal *w,
746 doublereal *z__, integer *ldz, doublereal *work, integer *iwork,
747 integer *ifail, integer *info)
749 /* System generated locals */
750 integer z_dim1, z_offset, i__1, i__2;
751 doublereal d__1, d__2;
753 /* Local variables */
755 doublereal rmin, rmax;
758 integer itmp1, i__, j;
759 extern /* Subroutine */ int dscal_(integer *, doublereal *, doublereal *,
762 extern logical lsame_(char *, char *);
764 extern /* Subroutine */ int dcopy_(integer *, doublereal *, integer *,
765 doublereal *, integer *), dswap_(integer *, doublereal *, integer
766 *, doublereal *, integer *);
769 extern doublereal dlamch_(char *);
770 logical alleig, indeig;
771 integer iscale, indibl;
774 extern /* Subroutine */ int xerbla_(char *, integer *, ftnlen);
776 extern doublereal dlanst_(char *, integer *, doublereal *, doublereal *);
778 extern /* Subroutine */ int dstein_(integer *, doublereal *, doublereal *,
779 integer *, doublereal *, integer *, integer *, doublereal *,
780 integer *, doublereal *, integer *, integer *, integer *),
781 dsterf_(integer *, doublereal *, doublereal *, integer *);
783 extern /* Subroutine */ int dstebz_(char *, char *, integer *, doublereal
784 *, doublereal *, integer *, integer *, doublereal *, doublereal *,
785 doublereal *, integer *, integer *, doublereal *, integer *,
786 integer *, doublereal *, integer *, integer *);
788 extern /* Subroutine */ int dsteqr_(char *, integer *, doublereal *,
789 doublereal *, doublereal *, integer *, doublereal *, integer *);
791 doublereal smlnum, eps, vll, vuu, tmp1;
794 /* -- LAPACK driver routine (version 3.7.0) -- */
795 /* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
796 /* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
800 /* ===================================================================== */
803 /* Test the input parameters. */
805 /* Parameter adjustments */
810 z_offset = 1 + z_dim1 * 1;
817 wantz = lsame_(jobz, "V");
818 alleig = lsame_(range, "A");
819 valeig = lsame_(range, "V");
820 indeig = lsame_(range, "I");
823 if (! (wantz || lsame_(jobz, "N"))) {
825 } else if (! (alleig || valeig || indeig)) {
831 if (*n > 0 && *vu <= *vl) {
835 if (*il < 1 || *il > f2cmax(1,*n)) {
837 } else if (*iu < f2cmin(*n,*il) || *iu > *n) {
843 if (*ldz < 1 || wantz && *ldz < *n) {
850 xerbla_("DSTEVX", &i__1, (ftnlen)6);
854 /* Quick return if possible */
862 if (alleig || indeig) {
866 if (*vl < d__[1] && *vu >= d__[1]) {
872 z__[z_dim1 + 1] = 1.;
877 /* Get machine constants. */
879 safmin = dlamch_("Safe minimum");
880 eps = dlamch_("Precision");
881 smlnum = safmin / eps;
882 bignum = 1. / smlnum;
885 d__1 = sqrt(bignum), d__2 = 1. / sqrt(sqrt(safmin));
886 rmax = f2cmin(d__1,d__2);
888 /* Scale matrix to allowable range, if necessary. */
898 tnrm = dlanst_("M", n, &d__[1], &e[1]);
899 if (tnrm > 0. && tnrm < rmin) {
902 } else if (tnrm > rmax) {
907 dscal_(n, &sigma, &d__[1], &c__1);
909 dscal_(&i__1, &sigma, &e[1], &c__1);
916 /* If all eigenvalues are desired and ABSTOL is less than zero, then */
917 /* call DSTERF or SSTEQR. If this fails for some eigenvalue, then */
922 if (*il == 1 && *iu == *n) {
926 if ((alleig || test) && *abstol <= 0.) {
927 dcopy_(n, &d__[1], &c__1, &w[1], &c__1);
929 dcopy_(&i__1, &e[1], &c__1, &work[1], &c__1);
932 dsterf_(n, &w[1], &work[1], info);
934 dsteqr_("I", n, &w[1], &work[1], &z__[z_offset], ldz, &work[
938 for (i__ = 1; i__ <= i__1; ++i__) {
951 /* Otherwise, call DSTEBZ and, if eigenvectors are desired, SSTEIN. */
954 *(unsigned char *)order = 'B';
956 *(unsigned char *)order = 'E';
960 indisp = indibl + *n;
961 indiwo = indisp + *n;
962 dstebz_(range, order, n, &vll, &vuu, il, iu, abstol, &d__[1], &e[1], m, &
963 nsplit, &w[1], &iwork[indibl], &iwork[indisp], &work[indwrk], &
964 iwork[indiwo], info);
967 dstein_(n, &d__[1], &e[1], m, &w[1], &iwork[indibl], &iwork[indisp], &
968 z__[z_offset], ldz, &work[indwrk], &iwork[indiwo], &ifail[1],
972 /* If matrix was scaled, then rescale eigenvalues appropriately. */
982 dscal_(&imax, &d__1, &w[1], &c__1);
985 /* If eigenvalues are not in order, then sort them, along with */
990 for (j = 1; j <= i__1; ++j) {
994 for (jj = j + 1; jj <= i__2; ++jj) {
1003 itmp1 = iwork[indibl + i__ - 1];
1005 iwork[indibl + i__ - 1] = iwork[indibl + j - 1];
1007 iwork[indibl + j - 1] = itmp1;
1008 dswap_(n, &z__[i__ * z_dim1 + 1], &c__1, &z__[j * z_dim1 + 1],
1012 ifail[i__] = ifail[j];