OpenBLAS/lapack-netlib/SRC/dlaebz.c

1225 lines
36 KiB
C

#include <math.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <complex.h>
#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 blasint logical;
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++ */
#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<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc._Val[0] += conjf(Cf(&x[i]))._Val[0] * Cf(&y[i])._Val[0];
zdotc._Val[1] += conjf(Cf(&x[i]))._Val[1] * Cf(&y[i])._Val[1];
}
} else {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc._Val[0] += conjf(Cf(&x[i*incx]))._Val[0] * Cf(&y[i*incy])._Val[0];
zdotc._Val[1] += conjf(Cf(&x[i*incx]))._Val[1] * Cf(&y[i*incy])._Val[1];
}
}
pCf(z) = zdotc;
}
#else
_Complex float zdotc = 0.0;
if (incx == 1 && incy == 1) {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc += conjf(Cf(&x[i])) * Cf(&y[i]);
}
} else {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc += conjf(Cf(&x[i*incx])) * Cf(&y[i*incy]);
}
}
pCf(z) = zdotc;
}
#endif
static inline void zdotc_(doublecomplex *z, integer *n_, doublecomplex *x, integer *incx_, doublecomplex *y, integer *incy_) {
integer n = *n_, incx = *incx_, incy = *incy_, i;
#ifdef _MSC_VER
_Dcomplex zdotc = {0.0, 0.0};
if (incx == 1 && incy == 1) {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc._Val[0] += conj(Cd(&x[i]))._Val[0] * Cd(&y[i])._Val[0];
zdotc._Val[1] += conj(Cd(&x[i]))._Val[1] * Cd(&y[i])._Val[1];
}
} else {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc._Val[0] += conj(Cd(&x[i*incx]))._Val[0] * Cd(&y[i*incy])._Val[0];
zdotc._Val[1] += conj(Cd(&x[i*incx]))._Val[1] * Cd(&y[i*incy])._Val[1];
}
}
pCd(z) = zdotc;
}
#else
_Complex double zdotc = 0.0;
if (incx == 1 && incy == 1) {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc += conj(Cd(&x[i])) * Cd(&y[i]);
}
} else {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc += conj(Cd(&x[i*incx])) * Cd(&y[i*incy]);
}
}
pCd(z) = zdotc;
}
#endif
static inline void cdotu_(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<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc._Val[0] += Cf(&x[i])._Val[0] * Cf(&y[i])._Val[0];
zdotc._Val[1] += Cf(&x[i])._Val[1] * Cf(&y[i])._Val[1];
}
} else {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc._Val[0] += Cf(&x[i*incx])._Val[0] * Cf(&y[i*incy])._Val[0];
zdotc._Val[1] += Cf(&x[i*incx])._Val[1] * Cf(&y[i*incy])._Val[1];
}
}
pCf(z) = zdotc;
}
#else
_Complex float zdotc = 0.0;
if (incx == 1 && incy == 1) {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc += Cf(&x[i]) * Cf(&y[i]);
}
} else {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc += Cf(&x[i*incx]) * Cf(&y[i*incy]);
}
}
pCf(z) = zdotc;
}
#endif
static inline void zdotu_(doublecomplex *z, integer *n_, doublecomplex *x, integer *incx_, doublecomplex *y, integer *incy_) {
integer n = *n_, incx = *incx_, incy = *incy_, i;
#ifdef _MSC_VER
_Dcomplex zdotc = {0.0, 0.0};
if (incx == 1 && incy == 1) {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc._Val[0] += Cd(&x[i])._Val[0] * Cd(&y[i])._Val[0];
zdotc._Val[1] += Cd(&x[i])._Val[1] * Cd(&y[i])._Val[1];
}
} else {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc._Val[0] += Cd(&x[i*incx])._Val[0] * Cd(&y[i*incy])._Val[0];
zdotc._Val[1] += Cd(&x[i*incx])._Val[1] * Cd(&y[i*incy])._Val[1];
}
}
pCd(z) = zdotc;
}
#else
_Complex double zdotc = 0.0;
if (incx == 1 && incy == 1) {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc += Cd(&x[i]) * Cd(&y[i]);
}
} else {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc += Cd(&x[i*incx]) * Cd(&y[i*incy]);
}
}
pCd(z) = zdotc;
}
#endif
/* -- translated by f2c (version 20000121).
You must link the resulting object file with the libraries:
-lf2c -lm (in that order)
*/
/* > \brief \b DLAEBZ computes the number of eigenvalues of a real symmetric tridiagonal matrix which are less
than or equal to a given value, and performs other tasks required by the routine sstebz. */
/* =========== DOCUMENTATION =========== */
/* Online html documentation available at */
/* http://www.netlib.org/lapack/explore-html/ */
/* > \htmlonly */
/* > Download DLAEBZ + dependencies */
/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dlaebz.
f"> */
/* > [TGZ]</a> */
/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dlaebz.
f"> */
/* > [ZIP]</a> */
/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dlaebz.
f"> */
/* > [TXT]</a> */
/* > \endhtmlonly */
/* Definition: */
/* =========== */
/* SUBROUTINE DLAEBZ( IJOB, NITMAX, N, MMAX, MINP, NBMIN, ABSTOL, */
/* RELTOL, PIVMIN, D, E, E2, NVAL, AB, C, MOUT, */
/* NAB, WORK, IWORK, INFO ) */
/* INTEGER IJOB, INFO, MINP, MMAX, MOUT, N, NBMIN, NITMAX */
/* DOUBLE PRECISION ABSTOL, PIVMIN, RELTOL */
/* INTEGER IWORK( * ), NAB( MMAX, * ), NVAL( * ) */
/* DOUBLE PRECISION AB( MMAX, * ), C( * ), D( * ), E( * ), E2( * ), */
/* $ WORK( * ) */
/* > \par Purpose: */
/* ============= */
/* > */
/* > \verbatim */
/* > */
/* > DLAEBZ contains the iteration loops which compute and use the */
/* > function N(w), which is the count of eigenvalues of a symmetric */
/* > tridiagonal matrix T less than or equal to its argument w. It */
/* > performs a choice of two types of loops: */
/* > */
/* > IJOB=1, followed by */
/* > IJOB=2: It takes as input a list of intervals and returns a list of */
/* > sufficiently small intervals whose union contains the same */
/* > eigenvalues as the union of the original intervals. */
/* > The input intervals are (AB(j,1),AB(j,2)], j=1,...,MINP. */
/* > The output interval (AB(j,1),AB(j,2)] will contain */
/* > eigenvalues NAB(j,1)+1,...,NAB(j,2), where 1 <= j <= MOUT. */
/* > */
/* > IJOB=3: It performs a binary search in each input interval */
/* > (AB(j,1),AB(j,2)] for a point w(j) such that */
/* > N(w(j))=NVAL(j), and uses C(j) as the starting point of */
/* > the search. If such a w(j) is found, then on output */
/* > AB(j,1)=AB(j,2)=w. If no such w(j) is found, then on output */
/* > (AB(j,1),AB(j,2)] will be a small interval containing the */
/* > point where N(w) jumps through NVAL(j), unless that point */
/* > lies outside the initial interval. */
/* > */
/* > Note that the intervals are in all cases half-open intervals, */
/* > i.e., of the form (a,b] , which includes b but not a . */
/* > */
/* > To avoid underflow, the matrix should be scaled so that its largest */
/* > element is no greater than overflow**(1/2) * underflow**(1/4) */
/* > in absolute value. To assure the most accurate computation */
/* > of small eigenvalues, the matrix should be scaled to be */
/* > not much smaller than that, either. */
/* > */
/* > See W. Kahan "Accurate Eigenvalues of a Symmetric Tridiagonal */
/* > Matrix", Report CS41, Computer Science Dept., Stanford */
/* > University, July 21, 1966 */
/* > */
/* > Note: the arguments are, in general, *not* checked for unreasonable */
/* > values. */
/* > \endverbatim */
/* Arguments: */
/* ========== */
/* > \param[in] IJOB */
/* > \verbatim */
/* > IJOB is INTEGER */
/* > Specifies what is to be done: */
/* > = 1: Compute NAB for the initial intervals. */
/* > = 2: Perform bisection iteration to find eigenvalues of T. */
/* > = 3: Perform bisection iteration to invert N(w), i.e., */
/* > to find a point which has a specified number of */
/* > eigenvalues of T to its left. */
/* > Other values will cause DLAEBZ to return with INFO=-1. */
/* > \endverbatim */
/* > */
/* > \param[in] NITMAX */
/* > \verbatim */
/* > NITMAX is INTEGER */
/* > The maximum number of "levels" of bisection to be */
/* > performed, i.e., an interval of width W will not be made */
/* > smaller than 2^(-NITMAX) * W. If not all intervals */
/* > have converged after NITMAX iterations, then INFO is set */
/* > to the number of non-converged intervals. */
/* > \endverbatim */
/* > */
/* > \param[in] N */
/* > \verbatim */
/* > N is INTEGER */
/* > The dimension n of the tridiagonal matrix T. It must be at */
/* > least 1. */
/* > \endverbatim */
/* > */
/* > \param[in] MMAX */
/* > \verbatim */
/* > MMAX is INTEGER */
/* > The maximum number of intervals. If more than MMAX intervals */
/* > are generated, then DLAEBZ will quit with INFO=MMAX+1. */
/* > \endverbatim */
/* > */
/* > \param[in] MINP */
/* > \verbatim */
/* > MINP is INTEGER */
/* > The initial number of intervals. It may not be greater than */
/* > MMAX. */
/* > \endverbatim */
/* > */
/* > \param[in] NBMIN */
/* > \verbatim */
/* > NBMIN is INTEGER */
/* > The smallest number of intervals that should be processed */
/* > using a vector loop. If zero, then only the scalar loop */
/* > will be used. */
/* > \endverbatim */
/* > */
/* > \param[in] ABSTOL */
/* > \verbatim */
/* > ABSTOL is DOUBLE PRECISION */
/* > The minimum (absolute) width of an interval. When an */
/* > interval is narrower than ABSTOL, or than RELTOL times the */
/* > larger (in magnitude) endpoint, then it is considered to be */
/* > sufficiently small, i.e., converged. This must be at least */
/* > zero. */
/* > \endverbatim */
/* > */
/* > \param[in] RELTOL */
/* > \verbatim */
/* > RELTOL is DOUBLE PRECISION */
/* > The minimum relative width of an interval. When an interval */
/* > is narrower than ABSTOL, or than RELTOL times the larger (in */
/* > magnitude) endpoint, then it is considered to be */
/* > sufficiently small, i.e., converged. Note: this should */
/* > always be at least radix*machine epsilon. */
/* > \endverbatim */
/* > */
/* > \param[in] PIVMIN */
/* > \verbatim */
/* > PIVMIN is DOUBLE PRECISION */
/* > The minimum absolute value of a "pivot" in the Sturm */
/* > sequence loop. */
/* > This must be at least f2cmax |e(j)**2|*safe_min and at */
/* > least safe_min, where safe_min is at least */
/* > the smallest number that can divide one without overflow. */
/* > \endverbatim */
/* > */
/* > \param[in] D */
/* > \verbatim */
/* > D is DOUBLE PRECISION array, dimension (N) */
/* > The diagonal elements of the tridiagonal matrix T. */
/* > \endverbatim */
/* > */
/* > \param[in] E */
/* > \verbatim */
/* > E is DOUBLE PRECISION array, dimension (N) */
/* > The offdiagonal elements of the tridiagonal matrix T in */
/* > positions 1 through N-1. E(N) is arbitrary. */
/* > \endverbatim */
/* > */
/* > \param[in] E2 */
/* > \verbatim */
/* > E2 is DOUBLE PRECISION array, dimension (N) */
/* > The squares of the offdiagonal elements of the tridiagonal */
/* > matrix T. E2(N) is ignored. */
/* > \endverbatim */
/* > */
/* > \param[in,out] NVAL */
/* > \verbatim */
/* > NVAL is INTEGER array, dimension (MINP) */
/* > If IJOB=1 or 2, not referenced. */
/* > If IJOB=3, the desired values of N(w). The elements of NVAL */
/* > will be reordered to correspond with the intervals in AB. */
/* > Thus, NVAL(j) on output will not, in general be the same as */
/* > NVAL(j) on input, but it will correspond with the interval */
/* > (AB(j,1),AB(j,2)] on output. */
/* > \endverbatim */
/* > */
/* > \param[in,out] AB */
/* > \verbatim */
/* > AB is DOUBLE PRECISION array, dimension (MMAX,2) */
/* > The endpoints of the intervals. AB(j,1) is a(j), the left */
/* > endpoint of the j-th interval, and AB(j,2) is b(j), the */
/* > right endpoint of the j-th interval. The input intervals */
/* > will, in general, be modified, split, and reordered by the */
/* > calculation. */
/* > \endverbatim */
/* > */
/* > \param[in,out] C */
/* > \verbatim */
/* > C is DOUBLE PRECISION array, dimension (MMAX) */
/* > If IJOB=1, ignored. */
/* > If IJOB=2, workspace. */
/* > If IJOB=3, then on input C(j) should be initialized to the */
/* > first search point in the binary search. */
/* > \endverbatim */
/* > */
/* > \param[out] MOUT */
/* > \verbatim */
/* > MOUT is INTEGER */
/* > If IJOB=1, the number of eigenvalues in the intervals. */
/* > If IJOB=2 or 3, the number of intervals output. */
/* > If IJOB=3, MOUT will equal MINP. */
/* > \endverbatim */
/* > */
/* > \param[in,out] NAB */
/* > \verbatim */
/* > NAB is INTEGER array, dimension (MMAX,2) */
/* > If IJOB=1, then on output NAB(i,j) will be set to N(AB(i,j)). */
/* > If IJOB=2, then on input, NAB(i,j) should be set. It must */
/* > satisfy the condition: */
/* > N(AB(i,1)) <= NAB(i,1) <= NAB(i,2) <= N(AB(i,2)), */
/* > which means that in interval i only eigenvalues */
/* > NAB(i,1)+1,...,NAB(i,2) will be considered. Usually, */
/* > NAB(i,j)=N(AB(i,j)), from a previous call to DLAEBZ with */
/* > IJOB=1. */
/* > On output, NAB(i,j) will contain */
/* > f2cmax(na(k),f2cmin(nb(k),N(AB(i,j)))), where k is the index of */
/* > the input interval that the output interval */
/* > (AB(j,1),AB(j,2)] came from, and na(k) and nb(k) are the */
/* > the input values of NAB(k,1) and NAB(k,2). */
/* > If IJOB=3, then on output, NAB(i,j) contains N(AB(i,j)), */
/* > unless N(w) > NVAL(i) for all search points w , in which */
/* > case NAB(i,1) will not be modified, i.e., the output */
/* > value will be the same as the input value (modulo */
/* > reorderings -- see NVAL and AB), or unless N(w) < NVAL(i) */
/* > for all search points w , in which case NAB(i,2) will */
/* > not be modified. Normally, NAB should be set to some */
/* > distinctive value(s) before DLAEBZ is called. */
/* > \endverbatim */
/* > */
/* > \param[out] WORK */
/* > \verbatim */
/* > WORK is DOUBLE PRECISION array, dimension (MMAX) */
/* > Workspace. */
/* > \endverbatim */
/* > */
/* > \param[out] IWORK */
/* > \verbatim */
/* > IWORK is INTEGER array, dimension (MMAX) */
/* > Workspace. */
/* > \endverbatim */
/* > */
/* > \param[out] INFO */
/* > \verbatim */
/* > INFO is INTEGER */
/* > = 0: All intervals converged. */
/* > = 1--MMAX: The last INFO intervals did not converge. */
/* > = MMAX+1: More than MMAX intervals were generated. */
/* > \endverbatim */
/* Authors: */
/* ======== */
/* > \author Univ. of Tennessee */
/* > \author Univ. of California Berkeley */
/* > \author Univ. of Colorado Denver */
/* > \author NAG Ltd. */
/* > \date December 2016 */
/* > \ingroup OTHERauxiliary */
/* > \par Further Details: */
/* ===================== */
/* > */
/* > \verbatim */
/* > */
/* > This routine is intended to be called only by other LAPACK */
/* > routines, thus the interface is less user-friendly. It is intended */
/* > for two purposes: */
/* > */
/* > (a) finding eigenvalues. In this case, DLAEBZ should have one or */
/* > more initial intervals set up in AB, and DLAEBZ should be called */
/* > with IJOB=1. This sets up NAB, and also counts the eigenvalues. */
/* > Intervals with no eigenvalues would usually be thrown out at */
/* > this point. Also, if not all the eigenvalues in an interval i */
/* > are desired, NAB(i,1) can be increased or NAB(i,2) decreased. */
/* > For example, set NAB(i,1)=NAB(i,2)-1 to get the largest */
/* > eigenvalue. DLAEBZ is then called with IJOB=2 and MMAX */
/* > no smaller than the value of MOUT returned by the call with */
/* > IJOB=1. After this (IJOB=2) call, eigenvalues NAB(i,1)+1 */
/* > through NAB(i,2) are approximately AB(i,1) (or AB(i,2)) to the */
/* > tolerance specified by ABSTOL and RELTOL. */
/* > */
/* > (b) finding an interval (a',b'] containing eigenvalues w(f),...,w(l). */
/* > In this case, start with a Gershgorin interval (a,b). Set up */
/* > AB to contain 2 search intervals, both initially (a,b). One */
/* > NVAL element should contain f-1 and the other should contain l */
/* > , while C should contain a and b, resp. NAB(i,1) should be -1 */
/* > and NAB(i,2) should be N+1, to flag an error if the desired */
/* > interval does not lie in (a,b). DLAEBZ is then called with */
/* > IJOB=3. On exit, if w(f-1) < w(f), then one of the intervals -- */
/* > j -- will have AB(j,1)=AB(j,2) and NAB(j,1)=NAB(j,2)=f-1, while */
/* > if, to the specified tolerance, w(f-k)=...=w(f+r), k > 0 and r */
/* > >= 0, then the interval will have N(AB(j,1))=NAB(j,1)=f-k and */
/* > N(AB(j,2))=NAB(j,2)=f+r. The cases w(l) < w(l+1) and */
/* > w(l-r)=...=w(l+k) are handled similarly. */
/* > \endverbatim */
/* > */
/* ===================================================================== */
/* Subroutine */ void dlaebz_(integer *ijob, integer *nitmax, integer *n,
integer *mmax, integer *minp, integer *nbmin, doublereal *abstol,
doublereal *reltol, doublereal *pivmin, doublereal *d__, doublereal *
e, doublereal *e2, integer *nval, doublereal *ab, doublereal *c__,
integer *mout, integer *nab, doublereal *work, integer *iwork,
integer *info)
{
/* System generated locals */
integer nab_dim1, nab_offset, ab_dim1, ab_offset, i__1, i__2, i__3, i__4,
i__5, i__6;
doublereal d__1, d__2, d__3, d__4;
/* Local variables */
integer itmp1, itmp2, j, kfnew, klnew, kf, ji, kl, jp, jit;
doublereal tmp1, tmp2;
/* -- LAPACK auxiliary routine (version 3.7.0) -- */
/* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
/* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
/* December 2016 */
/* ===================================================================== */
/* Check for Errors */
/* Parameter adjustments */
nab_dim1 = *mmax;
nab_offset = 1 + nab_dim1 * 1;
nab -= nab_offset;
ab_dim1 = *mmax;
ab_offset = 1 + ab_dim1 * 1;
ab -= ab_offset;
--d__;
--e;
--e2;
--nval;
--c__;
--work;
--iwork;
/* Function Body */
*info = 0;
if (*ijob < 1 || *ijob > 3) {
*info = -1;
return;
}
/* Initialize NAB */
if (*ijob == 1) {
/* Compute the number of eigenvalues in the initial intervals. */
*mout = 0;
i__1 = *minp;
for (ji = 1; ji <= i__1; ++ji) {
for (jp = 1; jp <= 2; ++jp) {
tmp1 = d__[1] - ab[ji + jp * ab_dim1];
if (abs(tmp1) < *pivmin) {
tmp1 = -(*pivmin);
}
nab[ji + jp * nab_dim1] = 0;
if (tmp1 <= 0.) {
nab[ji + jp * nab_dim1] = 1;
}
i__2 = *n;
for (j = 2; j <= i__2; ++j) {
tmp1 = d__[j] - e2[j - 1] / tmp1 - ab[ji + jp * ab_dim1];
if (abs(tmp1) < *pivmin) {
tmp1 = -(*pivmin);
}
if (tmp1 <= 0.) {
++nab[ji + jp * nab_dim1];
}
/* L10: */
}
/* L20: */
}
*mout = *mout + nab[ji + (nab_dim1 << 1)] - nab[ji + nab_dim1];
/* L30: */
}
return;
}
/* Initialize for loop */
/* KF and KL have the following meaning: */
/* Intervals 1,...,KF-1 have converged. */
/* Intervals KF,...,KL still need to be refined. */
kf = 1;
kl = *minp;
/* If IJOB=2, initialize C. */
/* If IJOB=3, use the user-supplied starting point. */
if (*ijob == 2) {
i__1 = *minp;
for (ji = 1; ji <= i__1; ++ji) {
c__[ji] = (ab[ji + ab_dim1] + ab[ji + (ab_dim1 << 1)]) * .5;
/* L40: */
}
}
/* Iteration loop */
i__1 = *nitmax;
for (jit = 1; jit <= i__1; ++jit) {
/* Loop over intervals */
if (kl - kf + 1 >= *nbmin && *nbmin > 0) {
/* Begin of Parallel Version of the loop */
i__2 = kl;
for (ji = kf; ji <= i__2; ++ji) {
/* Compute N(c), the number of eigenvalues less than c */
work[ji] = d__[1] - c__[ji];
iwork[ji] = 0;
if (work[ji] <= *pivmin) {
iwork[ji] = 1;
/* Computing MIN */
d__1 = work[ji], d__2 = -(*pivmin);
work[ji] = f2cmin(d__1,d__2);
}
i__3 = *n;
for (j = 2; j <= i__3; ++j) {
work[ji] = d__[j] - e2[j - 1] / work[ji] - c__[ji];
if (work[ji] <= *pivmin) {
++iwork[ji];
/* Computing MIN */
d__1 = work[ji], d__2 = -(*pivmin);
work[ji] = f2cmin(d__1,d__2);
}
/* L50: */
}
/* L60: */
}
if (*ijob <= 2) {
/* IJOB=2: Choose all intervals containing eigenvalues. */
klnew = kl;
i__2 = kl;
for (ji = kf; ji <= i__2; ++ji) {
/* Insure that N(w) is monotone */
/* Computing MIN */
/* Computing MAX */
i__5 = nab[ji + nab_dim1], i__6 = iwork[ji];
i__3 = nab[ji + (nab_dim1 << 1)], i__4 = f2cmax(i__5,i__6);
iwork[ji] = f2cmin(i__3,i__4);
/* Update the Queue -- add intervals if both halves */
/* contain eigenvalues. */
if (iwork[ji] == nab[ji + (nab_dim1 << 1)]) {
/* No eigenvalue in the upper interval: */
/* just use the lower interval. */
ab[ji + (ab_dim1 << 1)] = c__[ji];
} else if (iwork[ji] == nab[ji + nab_dim1]) {
/* No eigenvalue in the lower interval: */
/* just use the upper interval. */
ab[ji + ab_dim1] = c__[ji];
} else {
++klnew;
if (klnew <= *mmax) {
/* Eigenvalue in both intervals -- add upper to */
/* queue. */
ab[klnew + (ab_dim1 << 1)] = ab[ji + (ab_dim1 <<
1)];
nab[klnew + (nab_dim1 << 1)] = nab[ji + (nab_dim1
<< 1)];
ab[klnew + ab_dim1] = c__[ji];
nab[klnew + nab_dim1] = iwork[ji];
ab[ji + (ab_dim1 << 1)] = c__[ji];
nab[ji + (nab_dim1 << 1)] = iwork[ji];
} else {
*info = *mmax + 1;
}
}
/* L70: */
}
if (*info != 0) {
return;
}
kl = klnew;
} else {
/* IJOB=3: Binary search. Keep only the interval containing */
/* w s.t. N(w) = NVAL */
i__2 = kl;
for (ji = kf; ji <= i__2; ++ji) {
if (iwork[ji] <= nval[ji]) {
ab[ji + ab_dim1] = c__[ji];
nab[ji + nab_dim1] = iwork[ji];
}
if (iwork[ji] >= nval[ji]) {
ab[ji + (ab_dim1 << 1)] = c__[ji];
nab[ji + (nab_dim1 << 1)] = iwork[ji];
}
/* L80: */
}
}
} else {
/* End of Parallel Version of the loop */
/* Begin of Serial Version of the loop */
klnew = kl;
i__2 = kl;
for (ji = kf; ji <= i__2; ++ji) {
/* Compute N(w), the number of eigenvalues less than w */
tmp1 = c__[ji];
tmp2 = d__[1] - tmp1;
itmp1 = 0;
if (tmp2 <= *pivmin) {
itmp1 = 1;
/* Computing MIN */
d__1 = tmp2, d__2 = -(*pivmin);
tmp2 = f2cmin(d__1,d__2);
}
i__3 = *n;
for (j = 2; j <= i__3; ++j) {
tmp2 = d__[j] - e2[j - 1] / tmp2 - tmp1;
if (tmp2 <= *pivmin) {
++itmp1;
/* Computing MIN */
d__1 = tmp2, d__2 = -(*pivmin);
tmp2 = f2cmin(d__1,d__2);
}
/* L90: */
}
if (*ijob <= 2) {
/* IJOB=2: Choose all intervals containing eigenvalues. */
/* Insure that N(w) is monotone */
/* Computing MIN */
/* Computing MAX */
i__5 = nab[ji + nab_dim1];
i__3 = nab[ji + (nab_dim1 << 1)], i__4 = f2cmax(i__5,itmp1);
itmp1 = f2cmin(i__3,i__4);
/* Update the Queue -- add intervals if both halves */
/* contain eigenvalues. */
if (itmp1 == nab[ji + (nab_dim1 << 1)]) {
/* No eigenvalue in the upper interval: */
/* just use the lower interval. */
ab[ji + (ab_dim1 << 1)] = tmp1;
} else if (itmp1 == nab[ji + nab_dim1]) {
/* No eigenvalue in the lower interval: */
/* just use the upper interval. */
ab[ji + ab_dim1] = tmp1;
} else if (klnew < *mmax) {
/* Eigenvalue in both intervals -- add upper to queue. */
++klnew;
ab[klnew + (ab_dim1 << 1)] = ab[ji + (ab_dim1 << 1)];
nab[klnew + (nab_dim1 << 1)] = nab[ji + (nab_dim1 <<
1)];
ab[klnew + ab_dim1] = tmp1;
nab[klnew + nab_dim1] = itmp1;
ab[ji + (ab_dim1 << 1)] = tmp1;
nab[ji + (nab_dim1 << 1)] = itmp1;
} else {
*info = *mmax + 1;
return;
}
} else {
/* IJOB=3: Binary search. Keep only the interval */
/* containing w s.t. N(w) = NVAL */
if (itmp1 <= nval[ji]) {
ab[ji + ab_dim1] = tmp1;
nab[ji + nab_dim1] = itmp1;
}
if (itmp1 >= nval[ji]) {
ab[ji + (ab_dim1 << 1)] = tmp1;
nab[ji + (nab_dim1 << 1)] = itmp1;
}
}
/* L100: */
}
kl = klnew;
}
/* Check for convergence */
kfnew = kf;
i__2 = kl;
for (ji = kf; ji <= i__2; ++ji) {
tmp1 = (d__1 = ab[ji + (ab_dim1 << 1)] - ab[ji + ab_dim1], abs(
d__1));
/* Computing MAX */
d__3 = (d__1 = ab[ji + (ab_dim1 << 1)], abs(d__1)), d__4 = (d__2 =
ab[ji + ab_dim1], abs(d__2));
tmp2 = f2cmax(d__3,d__4);
/* Computing MAX */
d__1 = f2cmax(*abstol,*pivmin), d__2 = *reltol * tmp2;
if (tmp1 < f2cmax(d__1,d__2) || nab[ji + nab_dim1] >= nab[ji + (
nab_dim1 << 1)]) {
/* Converged -- Swap with position KFNEW, */
/* then increment KFNEW */
if (ji > kfnew) {
tmp1 = ab[ji + ab_dim1];
tmp2 = ab[ji + (ab_dim1 << 1)];
itmp1 = nab[ji + nab_dim1];
itmp2 = nab[ji + (nab_dim1 << 1)];
ab[ji + ab_dim1] = ab[kfnew + ab_dim1];
ab[ji + (ab_dim1 << 1)] = ab[kfnew + (ab_dim1 << 1)];
nab[ji + nab_dim1] = nab[kfnew + nab_dim1];
nab[ji + (nab_dim1 << 1)] = nab[kfnew + (nab_dim1 << 1)];
ab[kfnew + ab_dim1] = tmp1;
ab[kfnew + (ab_dim1 << 1)] = tmp2;
nab[kfnew + nab_dim1] = itmp1;
nab[kfnew + (nab_dim1 << 1)] = itmp2;
if (*ijob == 3) {
itmp1 = nval[ji];
nval[ji] = nval[kfnew];
nval[kfnew] = itmp1;
}
}
++kfnew;
}
/* L110: */
}
kf = kfnew;
/* Choose Midpoints */
i__2 = kl;
for (ji = kf; ji <= i__2; ++ji) {
c__[ji] = (ab[ji + ab_dim1] + ab[ji + (ab_dim1 << 1)]) * .5;
/* L120: */
}
/* If no more intervals to refine, quit. */
if (kf > kl) {
goto L140;
}
/* L130: */
}
/* Converged */
L140:
/* Computing MAX */
i__1 = kl + 1 - kf;
*info = f2cmax(i__1,0);
*mout = kl;
return;
/* End of DLAEBZ */
} /* dlaebz_ */