#include #include #include #include #include #ifdef complex #undef complex #endif #ifdef I #undef I #endif #if defined(_WIN64) typedef long long BLASLONG; typedef unsigned long long BLASULONG; #else typedef long BLASLONG; typedef unsigned long BLASULONG; #endif #ifdef LAPACK_ILP64 typedef BLASLONG blasint; #if defined(_WIN64) #define blasabs(x) llabs(x) #else #define blasabs(x) labs(x) #endif #else typedef int blasint; #define blasabs(x) abs(x) #endif typedef blasint integer; typedef unsigned int uinteger; typedef char *address; typedef short int shortint; typedef float real; typedef double doublereal; typedef struct { real r, i; } complex; typedef struct { doublereal r, i; } doublecomplex; #ifdef _MSC_VER static inline _Fcomplex Cf(complex *z) {_Fcomplex zz={z->r , z->i}; return zz;} static inline _Dcomplex Cd(doublecomplex *z) {_Dcomplex zz={z->r , z->i};return zz;} static inline _Fcomplex * _pCf(complex *z) {return (_Fcomplex*)z;} static inline _Dcomplex * _pCd(doublecomplex *z) {return (_Dcomplex*)z;} #else static inline _Complex float Cf(complex *z) {return z->r + z->i*_Complex_I;} static inline _Complex double Cd(doublecomplex *z) {return z->r + z->i*_Complex_I;} static inline _Complex float * _pCf(complex *z) {return (_Complex float*)z;} static inline _Complex double * _pCd(doublecomplex *z) {return (_Complex double*)z;} #endif #define pCf(z) (*_pCf(z)) #define pCd(z) (*_pCd(z)) typedef int logical; typedef short int shortlogical; typedef char logical1; typedef char integer1; #define TRUE_ (1) #define FALSE_ (0) /* Extern is for use with -E */ #ifndef Extern #define Extern extern #endif /* I/O stuff */ typedef int flag; typedef int ftnlen; typedef int ftnint; /*external read, write*/ typedef struct { flag cierr; ftnint ciunit; flag ciend; char *cifmt; ftnint cirec; } cilist; /*internal read, write*/ typedef struct { flag icierr; char *iciunit; flag iciend; char *icifmt; ftnint icirlen; ftnint icirnum; } icilist; /*open*/ typedef struct { flag oerr; ftnint ounit; char *ofnm; ftnlen ofnmlen; char *osta; char *oacc; char *ofm; ftnint orl; char *oblnk; } olist; /*close*/ typedef struct { flag cerr; ftnint cunit; char *csta; } cllist; /*rewind, backspace, endfile*/ typedef struct { flag aerr; ftnint aunit; } alist; /* inquire */ typedef struct { flag inerr; ftnint inunit; char *infile; ftnlen infilen; ftnint *inex; /*parameters in standard's order*/ ftnint *inopen; ftnint *innum; ftnint *innamed; char *inname; ftnlen innamlen; char *inacc; ftnlen inacclen; char *inseq; ftnlen inseqlen; char *indir; ftnlen indirlen; char *infmt; ftnlen infmtlen; char *inform; ftnint informlen; char *inunf; ftnlen inunflen; ftnint *inrecl; ftnint *innrec; char *inblank; ftnlen inblanklen; } inlist; #define VOID void union Multitype { /* for multiple entry points */ integer1 g; shortint h; integer i; /* longint j; */ real r; doublereal d; complex c; doublecomplex z; }; typedef union Multitype Multitype; struct Vardesc { /* for Namelist */ char *name; char *addr; ftnlen *dims; int type; }; typedef struct Vardesc Vardesc; struct Namelist { char *name; Vardesc **vars; int nvars; }; typedef struct Namelist Namelist; #define abs(x) ((x) >= 0 ? (x) : -(x)) #define dabs(x) (fabs(x)) #define f2cmin(a,b) ((a) <= (b) ? (a) : (b)) #define f2cmax(a,b) ((a) >= (b) ? (a) : (b)) #define dmin(a,b) (f2cmin(a,b)) #define dmax(a,b) (f2cmax(a,b)) #define bit_test(a,b) ((a) >> (b) & 1) #define bit_clear(a,b) ((a) & ~((uinteger)1 << (b))) #define bit_set(a,b) ((a) | ((uinteger)1 << (b))) #define abort_() { sig_die("Fortran abort routine called", 1); } #define c_abs(z) (cabsf(Cf(z))) #define c_cos(R,Z) { pCf(R)=ccos(Cf(Z)); } #ifdef _MSC_VER #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]);} #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]);} #else #define c_div(c, a, b) {pCf(c) = Cf(a)/Cf(b);} #define z_div(c, a, b) {pCd(c) = Cd(a)/Cd(b);} #endif #define c_exp(R, Z) {pCf(R) = cexpf(Cf(Z));} #define c_log(R, Z) {pCf(R) = clogf(Cf(Z));} #define c_sin(R, Z) {pCf(R) = csinf(Cf(Z));} //#define c_sqrt(R, Z) {*(R) = csqrtf(Cf(Z));} #define c_sqrt(R, Z) {pCf(R) = csqrtf(Cf(Z));} #define d_abs(x) (fabs(*(x))) #define d_acos(x) (acos(*(x))) #define d_asin(x) (asin(*(x))) #define d_atan(x) (atan(*(x))) #define d_atn2(x, y) (atan2(*(x),*(y))) #define d_cnjg(R, Z) { pCd(R) = conj(Cd(Z)); } #define r_cnjg(R, Z) { pCf(R) = conjf(Cf(Z)); } #define d_cos(x) (cos(*(x))) #define d_cosh(x) (cosh(*(x))) #define d_dim(__a, __b) ( *(__a) > *(__b) ? *(__a) - *(__b) : 0.0 ) #define d_exp(x) (exp(*(x))) #define d_imag(z) (cimag(Cd(z))) #define r_imag(z) (cimagf(Cf(z))) #define d_int(__x) (*(__x)>0 ? floor(*(__x)) : -floor(- *(__x))) #define r_int(__x) (*(__x)>0 ? floor(*(__x)) : -floor(- *(__x))) #define d_lg10(x) ( 0.43429448190325182765 * log(*(x)) ) #define r_lg10(x) ( 0.43429448190325182765 * log(*(x)) ) #define d_log(x) (log(*(x))) #define d_mod(x, y) (fmod(*(x), *(y))) #define u_nint(__x) ((__x)>=0 ? floor((__x) + .5) : -floor(.5 - (__x))) #define d_nint(x) u_nint(*(x)) #define u_sign(__a,__b) ((__b) >= 0 ? ((__a) >= 0 ? (__a) : -(__a)) : -((__a) >= 0 ? (__a) : -(__a))) #define d_sign(a,b) u_sign(*(a),*(b)) #define r_sign(a,b) u_sign(*(a),*(b)) #define d_sin(x) (sin(*(x))) #define d_sinh(x) (sinh(*(x))) #define d_sqrt(x) (sqrt(*(x))) #define d_tan(x) (tan(*(x))) #define d_tanh(x) (tanh(*(x))) #define i_abs(x) abs(*(x)) #define i_dnnt(x) ((integer)u_nint(*(x))) #define i_len(s, n) (n) #define i_nint(x) ((integer)u_nint(*(x))) #define i_sign(a,b) ((integer)u_sign((integer)*(a),(integer)*(b))) #define pow_dd(ap, bp) ( pow(*(ap), *(bp))) #define pow_si(B,E) spow_ui(*(B),*(E)) #define pow_ri(B,E) spow_ui(*(B),*(E)) #define pow_di(B,E) dpow_ui(*(B),*(E)) #define pow_zi(p, a, b) {pCd(p) = zpow_ui(Cd(a), *(b));} #define pow_ci(p, a, b) {pCf(p) = cpow_ui(Cf(a), *(b));} #define pow_zz(R,A,B) {pCd(R) = cpow(Cd(A),*(B));} #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++ = ' '; } #define s_cmp(a,b,c,d) ((integer)strncmp((a),(b),f2cmin((c),(d)))) #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]; } #define sig_die(s, kill) { exit(1); } #define s_stop(s, n) {exit(0);} static char junk[] = "\n@(#)LIBF77 VERSION 19990503\n"; #define z_abs(z) (cabs(Cd(z))) #define z_exp(R, Z) {pCd(R) = cexp(Cd(Z));} #define z_sqrt(R, Z) {pCd(R) = csqrt(Cd(Z));} #define myexit_() break; #define mycycle() continue; #define myceiling(w) {ceil(w)} #define myhuge(w) {HUGE_VAL} //#define mymaxloc_(w,s,e,n) {if (sizeof(*(w)) == sizeof(double)) dmaxloc_((w),*(s),*(e),n); else dmaxloc_((w),*(s),*(e),n);} #define mymaxloc(w,s,e,n) {dmaxloc_(w,*(s),*(e),n)} /* procedure parameter types for -A and -C++ */ #define F2C_proc_par_types 1 #ifdef __cplusplus typedef logical (*L_fp)(...); #else typedef logical (*L_fp)(); #endif static float spow_ui(float x, integer n) { float pow=1.0; unsigned long int u; if(n != 0) { if(n < 0) n = -n, x = 1/x; for(u = n; ; ) { if(u & 01) pow *= x; if(u >>= 1) x *= x; else break; } } return pow; } static double dpow_ui(double x, integer n) { double pow=1.0; unsigned long int u; if(n != 0) { if(n < 0) n = -n, x = 1/x; for(u = n; ; ) { if(u & 01) pow *= x; if(u >>= 1) x *= x; else break; } } return pow; } #ifdef _MSC_VER static _Fcomplex cpow_ui(complex x, integer n) { complex pow={1.0,0.0}; unsigned long int u; if(n != 0) { if(n < 0) n = -n, x.r = 1/x.r, x.i=1/x.i; for(u = n; ; ) { if(u & 01) pow.r *= x.r, pow.i *= x.i; if(u >>= 1) x.r *= x.r, x.i *= x.i; else break; } } _Fcomplex p={pow.r, pow.i}; return p; } #else static _Complex float cpow_ui(_Complex float x, integer n) { _Complex float pow=1.0; unsigned long int u; if(n != 0) { if(n < 0) n = -n, x = 1/x; for(u = n; ; ) { if(u & 01) pow *= x; if(u >>= 1) x *= x; else break; } } return pow; } #endif #ifdef _MSC_VER static _Dcomplex zpow_ui(_Dcomplex x, integer n) { _Dcomplex pow={1.0,0.0}; unsigned long int u; if(n != 0) { if(n < 0) n = -n, x._Val[0] = 1/x._Val[0], x._Val[1] =1/x._Val[1]; for(u = n; ; ) { if(u & 01) pow._Val[0] *= x._Val[0], pow._Val[1] *= x._Val[1]; if(u >>= 1) x._Val[0] *= x._Val[0], x._Val[1] *= x._Val[1]; else break; } } _Dcomplex p = {pow._Val[0], pow._Val[1]}; return p; } #else static _Complex double zpow_ui(_Complex double x, integer n) { _Complex double pow=1.0; unsigned long int u; if(n != 0) { if(n < 0) n = -n, x = 1/x; for(u = n; ; ) { if(u & 01) pow *= x; if(u >>= 1) x *= x; else break; } } return pow; } #endif static integer pow_ii(integer x, integer n) { integer pow; unsigned long int u; if (n <= 0) { if (n == 0 || x == 1) pow = 1; else if (x != -1) pow = x == 0 ? 1/x : 0; else n = -n; } if ((n > 0) || !(n == 0 || x == 1 || x != -1)) { u = n; for(pow = 1; ; ) { if(u & 01) pow *= x; if(u >>= 1) x *= x; else break; } } return pow; } static integer dmaxloc_(double *w, integer s, integer e, integer *n) { double m; integer i, mi; for(m=w[s-1], mi=s, i=s+1; i<=e; i++) if (w[i-1]>m) mi=i ,m=w[i-1]; return mi-s+1; } static integer smaxloc_(float *w, integer s, integer e, integer *n) { float m; integer i, mi; for(m=w[s-1], mi=s, i=s+1; i<=e; i++) if (w[i-1]>m) mi=i ,m=w[i-1]; return mi-s+1; } static inline void cdotc_(complex *z, integer *n_, complex *x, integer *incx_, complex *y, integer *incy_) { integer n = *n_, incx = *incx_, incy = *incy_, i; #ifdef _MSC_VER _Fcomplex zdotc = {0.0, 0.0}; if (incx == 1 && incy == 1) { for (i=0;i \brief \b DLARRB provides limited bisection to locate eigenvalues for more accuracy. */ /* =========== DOCUMENTATION =========== */ /* Online html documentation available at */ /* http://www.netlib.org/lapack/explore-html/ */ /* > \htmlonly */ /* > Download DLARRB + dependencies */ /* > */ /* > [TGZ] */ /* > */ /* > [ZIP] */ /* > */ /* > [TXT] */ /* > \endhtmlonly */ /* Definition: */ /* =========== */ /* SUBROUTINE DLARRB( N, D, LLD, IFIRST, ILAST, RTOL1, */ /* RTOL2, OFFSET, W, WGAP, WERR, WORK, IWORK, */ /* PIVMIN, SPDIAM, TWIST, INFO ) */ /* INTEGER IFIRST, ILAST, INFO, N, OFFSET, TWIST */ /* DOUBLE PRECISION PIVMIN, RTOL1, RTOL2, SPDIAM */ /* INTEGER IWORK( * ) */ /* DOUBLE PRECISION D( * ), LLD( * ), W( * ), */ /* $ WERR( * ), WGAP( * ), WORK( * ) */ /* > \par Purpose: */ /* ============= */ /* > */ /* > \verbatim */ /* > */ /* > Given the relatively robust representation(RRR) L D L^T, DLARRB */ /* > does "limited" bisection to refine the eigenvalues of L D L^T, */ /* > W( IFIRST-OFFSET ) through W( ILAST-OFFSET ), to more accuracy. Initial */ /* > guesses for these eigenvalues are input in W, the corresponding estimate */ /* > of the error in these guesses and their gaps are input in WERR */ /* > and WGAP, respectively. During bisection, intervals */ /* > [left, right] are maintained by storing their mid-points and */ /* > semi-widths in the arrays W and WERR respectively. */ /* > \endverbatim */ /* Arguments: */ /* ========== */ /* > \param[in] N */ /* > \verbatim */ /* > N is INTEGER */ /* > The order of the matrix. */ /* > \endverbatim */ /* > */ /* > \param[in] D */ /* > \verbatim */ /* > D is DOUBLE PRECISION array, dimension (N) */ /* > The N diagonal elements of the diagonal matrix D. */ /* > \endverbatim */ /* > */ /* > \param[in] LLD */ /* > \verbatim */ /* > LLD is DOUBLE PRECISION array, dimension (N-1) */ /* > The (N-1) elements L(i)*L(i)*D(i). */ /* > \endverbatim */ /* > */ /* > \param[in] IFIRST */ /* > \verbatim */ /* > IFIRST is INTEGER */ /* > The index of the first eigenvalue to be computed. */ /* > \endverbatim */ /* > */ /* > \param[in] ILAST */ /* > \verbatim */ /* > ILAST is INTEGER */ /* > The index of the last eigenvalue to be computed. */ /* > \endverbatim */ /* > */ /* > \param[in] RTOL1 */ /* > \verbatim */ /* > RTOL1 is DOUBLE PRECISION */ /* > \endverbatim */ /* > */ /* > \param[in] RTOL2 */ /* > \verbatim */ /* > RTOL2 is DOUBLE PRECISION */ /* > Tolerance for the convergence of the bisection intervals. */ /* > An interval [LEFT,RIGHT] has converged if */ /* > RIGHT-LEFT < MAX( RTOL1*GAP, RTOL2*MAX(|LEFT|,|RIGHT|) ) */ /* > where GAP is the (estimated) distance to the nearest */ /* > eigenvalue. */ /* > \endverbatim */ /* > */ /* > \param[in] OFFSET */ /* > \verbatim */ /* > OFFSET is INTEGER */ /* > Offset for the arrays W, WGAP and WERR, i.e., the IFIRST-OFFSET */ /* > through ILAST-OFFSET elements of these arrays are to be used. */ /* > \endverbatim */ /* > */ /* > \param[in,out] W */ /* > \verbatim */ /* > W is DOUBLE PRECISION array, dimension (N) */ /* > On input, W( IFIRST-OFFSET ) through W( ILAST-OFFSET ) are */ /* > estimates of the eigenvalues of L D L^T indexed IFIRST through */ /* > ILAST. */ /* > On output, these estimates are refined. */ /* > \endverbatim */ /* > */ /* > \param[in,out] WGAP */ /* > \verbatim */ /* > WGAP is DOUBLE PRECISION array, dimension (N-1) */ /* > On input, the (estimated) gaps between consecutive */ /* > eigenvalues of L D L^T, i.e., WGAP(I-OFFSET) is the gap between */ /* > eigenvalues I and I+1. Note that if IFIRST = ILAST */ /* > then WGAP(IFIRST-OFFSET) must be set to ZERO. */ /* > On output, these gaps are refined. */ /* > \endverbatim */ /* > */ /* > \param[in,out] WERR */ /* > \verbatim */ /* > WERR is DOUBLE PRECISION array, dimension (N) */ /* > On input, WERR( IFIRST-OFFSET ) through WERR( ILAST-OFFSET ) are */ /* > the errors in the estimates of the corresponding elements in W. */ /* > On output, these errors are refined. */ /* > \endverbatim */ /* > */ /* > \param[out] WORK */ /* > \verbatim */ /* > WORK is DOUBLE PRECISION array, dimension (2*N) */ /* > Workspace. */ /* > \endverbatim */ /* > */ /* > \param[out] IWORK */ /* > \verbatim */ /* > IWORK is INTEGER array, dimension (2*N) */ /* > Workspace. */ /* > \endverbatim */ /* > */ /* > \param[in] PIVMIN */ /* > \verbatim */ /* > PIVMIN is DOUBLE PRECISION */ /* > The minimum pivot in the Sturm sequence. */ /* > \endverbatim */ /* > */ /* > \param[in] SPDIAM */ /* > \verbatim */ /* > SPDIAM is DOUBLE PRECISION */ /* > The spectral diameter of the matrix. */ /* > \endverbatim */ /* > */ /* > \param[in] TWIST */ /* > \verbatim */ /* > TWIST is INTEGER */ /* > The twist index for the twisted factorization that is used */ /* > for the negcount. */ /* > TWIST = N: Compute negcount from L D L^T - LAMBDA I = L+ D+ L+^T */ /* > TWIST = 1: Compute negcount from L D L^T - LAMBDA I = U- D- U-^T */ /* > TWIST = R: Compute negcount from L D L^T - LAMBDA I = N(r) D(r) N(r) */ /* > \endverbatim */ /* > */ /* > \param[out] INFO */ /* > \verbatim */ /* > INFO is INTEGER */ /* > Error flag. */ /* > \endverbatim */ /* Authors: */ /* ======== */ /* > \author Univ. of Tennessee */ /* > \author Univ. of California Berkeley */ /* > \author Univ. of Colorado Denver */ /* > \author NAG Ltd. */ /* > \date June 2017 */ /* > \ingroup OTHERauxiliary */ /* > \par Contributors: */ /* ================== */ /* > */ /* > Beresford Parlett, University of California, Berkeley, USA \n */ /* > Jim Demmel, University of California, Berkeley, USA \n */ /* > Inderjit Dhillon, University of Texas, Austin, USA \n */ /* > Osni Marques, LBNL/NERSC, USA \n */ /* > Christof Voemel, University of California, Berkeley, USA */ /* ===================================================================== */ /* Subroutine */ int dlarrb_(integer *n, doublereal *d__, doublereal *lld, integer *ifirst, integer *ilast, doublereal *rtol1, doublereal *rtol2, integer *offset, doublereal *w, doublereal *wgap, doublereal *werr, doublereal *work, integer *iwork, doublereal *pivmin, doublereal * spdiam, integer *twist, integer *info) { /* System generated locals */ integer i__1; doublereal d__1, d__2; /* Local variables */ doublereal back, lgap, rgap, left; integer iter, nint, prev, next, i__, k, r__; doublereal cvrgd, right, width; integer i1, ii, ip; extern integer dlaneg_(integer *, doublereal *, doublereal *, doublereal * , doublereal *, integer *); integer negcnt; doublereal mnwdth; integer olnint, maxitr; doublereal gap, mid, tmp; /* -- LAPACK auxiliary routine (version 3.7.1) -- */ /* -- LAPACK is a software package provided by Univ. of Tennessee, -- */ /* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */ /* June 2017 */ /* ===================================================================== */ /* Parameter adjustments */ --iwork; --work; --werr; --wgap; --w; --lld; --d__; /* Function Body */ *info = 0; /* Quick return if possible */ if (*n <= 0) { return 0; } maxitr = (integer) ((log(*spdiam + *pivmin) - log(*pivmin)) / log(2.)) + 2; mnwdth = *pivmin * 2.; r__ = *twist; if (r__ < 1 || r__ > *n) { r__ = *n; } /* Initialize unconverged intervals in [ WORK(2*I-1), WORK(2*I) ]. */ /* The Sturm Count, Count( WORK(2*I-1) ) is arranged to be I-1, while */ /* Count( WORK(2*I) ) is stored in IWORK( 2*I ). The integer IWORK( 2*I-1 ) */ /* for an unconverged interval is set to the index of the next unconverged */ /* interval, and is -1 or 0 for a converged interval. Thus a linked */ /* list of unconverged intervals is set up. */ i1 = *ifirst; /* The number of unconverged intervals */ nint = 0; /* The last unconverged interval found */ prev = 0; rgap = wgap[i1 - *offset]; i__1 = *ilast; for (i__ = i1; i__ <= i__1; ++i__) { k = i__ << 1; ii = i__ - *offset; left = w[ii] - werr[ii]; right = w[ii] + werr[ii]; lgap = rgap; rgap = wgap[ii]; gap = f2cmin(lgap,rgap); /* Make sure that [LEFT,RIGHT] contains the desired eigenvalue */ /* Compute negcount from dstqds facto L+D+L+^T = L D L^T - LEFT */ /* Do while( NEGCNT(LEFT).GT.I-1 ) */ back = werr[ii]; L20: negcnt = dlaneg_(n, &d__[1], &lld[1], &left, pivmin, &r__); if (negcnt > i__ - 1) { left -= back; back *= 2.; goto L20; } /* Do while( NEGCNT(RIGHT).LT.I ) */ /* Compute negcount from dstqds facto L+D+L+^T = L D L^T - RIGHT */ back = werr[ii]; L50: negcnt = dlaneg_(n, &d__[1], &lld[1], &right, pivmin, &r__); if (negcnt < i__) { right += back; back *= 2.; goto L50; } width = (d__1 = left - right, abs(d__1)) * .5; /* Computing MAX */ d__1 = abs(left), d__2 = abs(right); tmp = f2cmax(d__1,d__2); /* Computing MAX */ d__1 = *rtol1 * gap, d__2 = *rtol2 * tmp; cvrgd = f2cmax(d__1,d__2); if (width <= cvrgd || width <= mnwdth) { /* This interval has already converged and does not need refinement. */ /* (Note that the gaps might change through refining the */ /* eigenvalues, however, they can only get bigger.) */ /* Remove it from the list. */ iwork[k - 1] = -1; /* Make sure that I1 always points to the first unconverged interval */ if (i__ == i1 && i__ < *ilast) { i1 = i__ + 1; } if (prev >= i1 && i__ <= *ilast) { iwork[(prev << 1) - 1] = i__ + 1; } } else { /* unconverged interval found */ prev = i__; ++nint; iwork[k - 1] = i__ + 1; iwork[k] = negcnt; } work[k - 1] = left; work[k] = right; /* L75: */ } /* Do while( NINT.GT.0 ), i.e. there are still unconverged intervals */ /* and while (ITER.LT.MAXITR) */ iter = 0; L80: prev = i1 - 1; i__ = i1; olnint = nint; i__1 = olnint; for (ip = 1; ip <= i__1; ++ip) { k = i__ << 1; ii = i__ - *offset; rgap = wgap[ii]; lgap = rgap; if (ii > 1) { lgap = wgap[ii - 1]; } gap = f2cmin(lgap,rgap); next = iwork[k - 1]; left = work[k - 1]; right = work[k]; mid = (left + right) * .5; /* semiwidth of interval */ width = right - mid; /* Computing MAX */ d__1 = abs(left), d__2 = abs(right); tmp = f2cmax(d__1,d__2); /* Computing MAX */ d__1 = *rtol1 * gap, d__2 = *rtol2 * tmp; cvrgd = f2cmax(d__1,d__2); if (width <= cvrgd || width <= mnwdth || iter == maxitr) { /* reduce number of unconverged intervals */ --nint; /* Mark interval as converged. */ iwork[k - 1] = 0; if (i1 == i__) { i1 = next; } else { /* Prev holds the last unconverged interval previously examined */ if (prev >= i1) { iwork[(prev << 1) - 1] = next; } } i__ = next; goto L100; } prev = i__; /* Perform one bisection step */ negcnt = dlaneg_(n, &d__[1], &lld[1], &mid, pivmin, &r__); if (negcnt <= i__ - 1) { work[k - 1] = mid; } else { work[k] = mid; } i__ = next; L100: ; } ++iter; /* do another loop if there are still unconverged intervals */ /* However, in the last iteration, all intervals are accepted */ /* since this is the best we can do. */ if (nint > 0 && iter <= maxitr) { goto L80; } /* At this point, all the intervals have converged */ i__1 = *ilast; for (i__ = *ifirst; i__ <= i__1; ++i__) { k = i__ << 1; ii = i__ - *offset; /* All intervals marked by '0' have been refined. */ if (iwork[k - 1] == 0) { w[ii] = (work[k - 1] + work[k]) * .5; werr[ii] = work[k] - w[ii]; } /* L110: */ } i__1 = *ilast; for (i__ = *ifirst + 1; i__ <= i__1; ++i__) { k = i__ << 1; ii = i__ - *offset; /* Computing MAX */ d__1 = 0., d__2 = w[ii] - werr[ii] - w[ii - 1] - werr[ii - 1]; wgap[ii - 1] = f2cmax(d__1,d__2); /* L111: */ } return 0; /* End of DLARRB */ } /* dlarrb_ */