591 lines
20 KiB
C++
591 lines
20 KiB
C++
/* fortran/zstedc.f -- translated by f2c (version 20200916).
|
|
You must link the resulting object file with libf2c:
|
|
on Microsoft Windows system, link with libf2c.lib;
|
|
on Linux or Unix systems, link with .../path/to/libf2c.a -lm
|
|
or, if you install libf2c.a in a standard place, with -lf2c -lm
|
|
-- in that order, at the end of the command line, as in
|
|
cc *.o -lf2c -lm
|
|
Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,
|
|
|
|
http://www.netlib.org/f2c/libf2c.zip
|
|
*/
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
#include "lmp_f2c.h"
|
|
|
|
/* Table of constant values */
|
|
|
|
static integer c__9 = 9;
|
|
static integer c__0 = 0;
|
|
static integer c__2 = 2;
|
|
static doublereal c_b17 = 0.;
|
|
static doublereal c_b18 = 1.;
|
|
static integer c__1 = 1;
|
|
|
|
/* > \brief \b ZSTEDC */
|
|
|
|
/* =========== DOCUMENTATION =========== */
|
|
|
|
/* Online html documentation available at */
|
|
/* http://www.netlib.org/lapack/explore-html/ */
|
|
|
|
/* > \htmlonly */
|
|
/* > Download ZSTEDC + dependencies */
|
|
/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/zstedc.
|
|
f"> */
|
|
/* > [TGZ]</a> */
|
|
/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/zstedc.
|
|
f"> */
|
|
/* > [ZIP]</a> */
|
|
/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/zstedc.
|
|
f"> */
|
|
/* > [TXT]</a> */
|
|
/* > \endhtmlonly */
|
|
|
|
/* Definition: */
|
|
/* =========== */
|
|
|
|
/* SUBROUTINE ZSTEDC( COMPZ, N, D, E, Z, LDZ, WORK, LWORK, RWORK, */
|
|
/* LRWORK, IWORK, LIWORK, INFO ) */
|
|
|
|
/* .. Scalar Arguments .. */
|
|
/* CHARACTER COMPZ */
|
|
/* INTEGER INFO, LDZ, LIWORK, LRWORK, LWORK, N */
|
|
/* .. */
|
|
/* .. Array Arguments .. */
|
|
/* INTEGER IWORK( * ) */
|
|
/* DOUBLE PRECISION D( * ), E( * ), RWORK( * ) */
|
|
/* COMPLEX*16 WORK( * ), Z( LDZ, * ) */
|
|
/* .. */
|
|
|
|
|
|
/* > \par Purpose: */
|
|
/* ============= */
|
|
/* > */
|
|
/* > \verbatim */
|
|
/* > */
|
|
/* > ZSTEDC computes all eigenvalues and, optionally, eigenvectors of a */
|
|
/* > symmetric tridiagonal matrix using the divide and conquer method. */
|
|
/* > The eigenvectors of a full or band complex Hermitian matrix can also */
|
|
/* > be found if ZHETRD or ZHPTRD or ZHBTRD has been used to reduce this */
|
|
/* > matrix to tridiagonal form. */
|
|
/* > */
|
|
/* > This code makes very mild assumptions about floating point */
|
|
/* > arithmetic. It will work on machines with a guard digit in */
|
|
/* > add/subtract, or on those binary machines without guard digits */
|
|
/* > which subtract like the Cray X-MP, Cray Y-MP, Cray C-90, or Cray-2. */
|
|
/* > It could conceivably fail on hexadecimal or decimal machines */
|
|
/* > without guard digits, but we know of none. See DLAED3 for details. */
|
|
/* > \endverbatim */
|
|
|
|
/* Arguments: */
|
|
/* ========== */
|
|
|
|
/* > \param[in] COMPZ */
|
|
/* > \verbatim */
|
|
/* > COMPZ is CHARACTER*1 */
|
|
/* > = 'N': Compute eigenvalues only. */
|
|
/* > = 'I': Compute eigenvectors of tridiagonal matrix also. */
|
|
/* > = 'V': Compute eigenvectors of original Hermitian matrix */
|
|
/* > also. On entry, Z contains the unitary matrix used */
|
|
/* > to reduce the original matrix to tridiagonal form. */
|
|
/* > \endverbatim */
|
|
/* > */
|
|
/* > \param[in] N */
|
|
/* > \verbatim */
|
|
/* > N is INTEGER */
|
|
/* > The dimension of the symmetric tridiagonal matrix. N >= 0. */
|
|
/* > \endverbatim */
|
|
/* > */
|
|
/* > \param[in,out] D */
|
|
/* > \verbatim */
|
|
/* > D is DOUBLE PRECISION array, dimension (N) */
|
|
/* > On entry, the diagonal elements of the tridiagonal matrix. */
|
|
/* > On exit, if INFO = 0, the eigenvalues in ascending order. */
|
|
/* > \endverbatim */
|
|
/* > */
|
|
/* > \param[in,out] E */
|
|
/* > \verbatim */
|
|
/* > E is DOUBLE PRECISION array, dimension (N-1) */
|
|
/* > On entry, the subdiagonal elements of the tridiagonal matrix. */
|
|
/* > On exit, E has been destroyed. */
|
|
/* > \endverbatim */
|
|
/* > */
|
|
/* > \param[in,out] Z */
|
|
/* > \verbatim */
|
|
/* > Z is COMPLEX*16 array, dimension (LDZ,N) */
|
|
/* > On entry, if COMPZ = 'V', then Z contains the unitary */
|
|
/* > matrix used in the reduction to tridiagonal form. */
|
|
/* > On exit, if INFO = 0, then if COMPZ = 'V', Z contains the */
|
|
/* > orthonormal eigenvectors of the original Hermitian matrix, */
|
|
/* > and if COMPZ = 'I', Z contains the orthonormal eigenvectors */
|
|
/* > of the symmetric tridiagonal matrix. */
|
|
/* > If COMPZ = 'N', then Z is not referenced. */
|
|
/* > \endverbatim */
|
|
/* > */
|
|
/* > \param[in] LDZ */
|
|
/* > \verbatim */
|
|
/* > LDZ is INTEGER */
|
|
/* > The leading dimension of the array Z. LDZ >= 1. */
|
|
/* > If eigenvectors are desired, then LDZ >= max(1,N). */
|
|
/* > \endverbatim */
|
|
/* > */
|
|
/* > \param[out] WORK */
|
|
/* > \verbatim */
|
|
/* > WORK is COMPLEX*16 array, dimension (MAX(1,LWORK)) */
|
|
/* > On exit, if INFO = 0, WORK(1) returns the optimal LWORK. */
|
|
/* > \endverbatim */
|
|
/* > */
|
|
/* > \param[in] LWORK */
|
|
/* > \verbatim */
|
|
/* > LWORK is INTEGER */
|
|
/* > The dimension of the array WORK. */
|
|
/* > If COMPZ = 'N' or 'I', or N <= 1, LWORK must be at least 1. */
|
|
/* > If COMPZ = 'V' and N > 1, LWORK must be at least N*N. */
|
|
/* > Note that for COMPZ = 'V', then if N is less than or */
|
|
/* > equal to the minimum divide size, usually 25, then LWORK need */
|
|
/* > only be 1. */
|
|
/* > */
|
|
/* > If LWORK = -1, then a workspace query is assumed; the routine */
|
|
/* > only calculates the optimal sizes of the WORK, RWORK and */
|
|
/* > IWORK arrays, returns these values as the first entries of */
|
|
/* > the WORK, RWORK and IWORK arrays, and no error message */
|
|
/* > related to LWORK or LRWORK or LIWORK is issued by XERBLA. */
|
|
/* > \endverbatim */
|
|
/* > */
|
|
/* > \param[out] RWORK */
|
|
/* > \verbatim */
|
|
/* > RWORK is DOUBLE PRECISION array, dimension (MAX(1,LRWORK)) */
|
|
/* > On exit, if INFO = 0, RWORK(1) returns the optimal LRWORK. */
|
|
/* > \endverbatim */
|
|
/* > */
|
|
/* > \param[in] LRWORK */
|
|
/* > \verbatim */
|
|
/* > LRWORK is INTEGER */
|
|
/* > The dimension of the array RWORK. */
|
|
/* > If COMPZ = 'N' or N <= 1, LRWORK must be at least 1. */
|
|
/* > If COMPZ = 'V' and N > 1, LRWORK must be at least */
|
|
/* > 1 + 3*N + 2*N*lg N + 4*N**2 , */
|
|
/* > where lg( N ) = smallest integer k such */
|
|
/* > that 2**k >= N. */
|
|
/* > If COMPZ = 'I' and N > 1, LRWORK must be at least */
|
|
/* > 1 + 4*N + 2*N**2 . */
|
|
/* > Note that for COMPZ = 'I' or 'V', then if N is less than or */
|
|
/* > equal to the minimum divide size, usually 25, then LRWORK */
|
|
/* > need only be max(1,2*(N-1)). */
|
|
/* > */
|
|
/* > If LRWORK = -1, then a workspace query is assumed; the */
|
|
/* > routine only calculates the optimal sizes of the WORK, RWORK */
|
|
/* > and IWORK arrays, returns these values as the first entries */
|
|
/* > of the WORK, RWORK and IWORK arrays, and no error message */
|
|
/* > related to LWORK or LRWORK or LIWORK is issued by XERBLA. */
|
|
/* > \endverbatim */
|
|
/* > */
|
|
/* > \param[out] IWORK */
|
|
/* > \verbatim */
|
|
/* > IWORK is INTEGER array, dimension (MAX(1,LIWORK)) */
|
|
/* > On exit, if INFO = 0, IWORK(1) returns the optimal LIWORK. */
|
|
/* > \endverbatim */
|
|
/* > */
|
|
/* > \param[in] LIWORK */
|
|
/* > \verbatim */
|
|
/* > LIWORK is INTEGER */
|
|
/* > The dimension of the array IWORK. */
|
|
/* > If COMPZ = 'N' or N <= 1, LIWORK must be at least 1. */
|
|
/* > If COMPZ = 'V' or N > 1, LIWORK must be at least */
|
|
/* > 6 + 6*N + 5*N*lg N. */
|
|
/* > If COMPZ = 'I' or N > 1, LIWORK must be at least */
|
|
/* > 3 + 5*N . */
|
|
/* > Note that for COMPZ = 'I' or 'V', then if N is less than or */
|
|
/* > equal to the minimum divide size, usually 25, then LIWORK */
|
|
/* > need only be 1. */
|
|
/* > */
|
|
/* > If LIWORK = -1, then a workspace query is assumed; the */
|
|
/* > routine only calculates the optimal sizes of the WORK, RWORK */
|
|
/* > and IWORK arrays, returns these values as the first entries */
|
|
/* > of the WORK, RWORK and IWORK arrays, and no error message */
|
|
/* > related to LWORK or LRWORK or LIWORK is issued by XERBLA. */
|
|
/* > \endverbatim */
|
|
/* > */
|
|
/* > \param[out] INFO */
|
|
/* > \verbatim */
|
|
/* > INFO is INTEGER */
|
|
/* > = 0: successful exit. */
|
|
/* > < 0: if INFO = -i, the i-th argument had an illegal value. */
|
|
/* > > 0: The algorithm failed to compute an eigenvalue while */
|
|
/* > working on the submatrix lying in rows and columns */
|
|
/* > INFO/(N+1) through mod(INFO,N+1). */
|
|
/* > \endverbatim */
|
|
|
|
/* Authors: */
|
|
/* ======== */
|
|
|
|
/* > \author Univ. of Tennessee */
|
|
/* > \author Univ. of California Berkeley */
|
|
/* > \author Univ. of Colorado Denver */
|
|
/* > \author NAG Ltd. */
|
|
|
|
/* > \ingroup complex16OTHERcomputational */
|
|
|
|
/* > \par Contributors: */
|
|
/* ================== */
|
|
/* > */
|
|
/* > Jeff Rutter, Computer Science Division, University of California */
|
|
/* > at Berkeley, USA */
|
|
|
|
/* ===================================================================== */
|
|
/* Subroutine */ int zstedc_(char *compz, integer *n, doublereal *d__,
|
|
doublereal *e, doublecomplex *z__, integer *ldz, doublecomplex *work,
|
|
integer *lwork, doublereal *rwork, integer *lrwork, integer *iwork,
|
|
integer *liwork, integer *info, ftnlen compz_len)
|
|
{
|
|
/* System generated locals */
|
|
integer z_dim1, z_offset, i__1, i__2, i__3, i__4;
|
|
doublereal d__1, d__2;
|
|
|
|
/* Builtin functions */
|
|
double log(doublereal);
|
|
integer pow_ii(integer *, integer *);
|
|
double sqrt(doublereal);
|
|
|
|
/* Local variables */
|
|
integer i__, j, k, m;
|
|
doublereal p;
|
|
integer ii, ll, lgn;
|
|
doublereal eps, tiny;
|
|
extern logical lsame_(char *, char *, ftnlen, ftnlen);
|
|
integer lwmin, start;
|
|
extern /* Subroutine */ int zswap_(integer *, doublecomplex *, integer *,
|
|
doublecomplex *, integer *), zlaed0_(integer *, integer *,
|
|
doublereal *, doublereal *, doublecomplex *, integer *,
|
|
doublecomplex *, integer *, doublereal *, integer *, integer *);
|
|
extern doublereal dlamch_(char *, ftnlen);
|
|
extern /* Subroutine */ int dlascl_(char *, integer *, integer *,
|
|
doublereal *, doublereal *, integer *, integer *, doublereal *,
|
|
integer *, integer *, ftnlen), dstedc_(char *, integer *,
|
|
doublereal *, doublereal *, doublereal *, integer *, doublereal *,
|
|
integer *, integer *, integer *, integer *, ftnlen), dlaset_(
|
|
char *, integer *, integer *, doublereal *, doublereal *,
|
|
doublereal *, integer *, ftnlen), xerbla_(char *, integer *,
|
|
ftnlen);
|
|
extern integer ilaenv_(integer *, char *, char *, integer *, integer *,
|
|
integer *, integer *, ftnlen, ftnlen);
|
|
integer finish;
|
|
extern doublereal dlanst_(char *, integer *, doublereal *, doublereal *,
|
|
ftnlen);
|
|
extern /* Subroutine */ int dsterf_(integer *, doublereal *, doublereal *,
|
|
integer *), zlacrm_(integer *, integer *, doublecomplex *,
|
|
integer *, doublereal *, integer *, doublecomplex *, integer *,
|
|
doublereal *);
|
|
integer liwmin, icompz;
|
|
extern /* Subroutine */ int dsteqr_(char *, integer *, doublereal *,
|
|
doublereal *, doublereal *, integer *, doublereal *, integer *,
|
|
ftnlen), zlacpy_(char *, integer *, integer *, doublecomplex *,
|
|
integer *, doublecomplex *, integer *, ftnlen);
|
|
doublereal orgnrm;
|
|
integer lrwmin;
|
|
logical lquery;
|
|
integer smlsiz;
|
|
extern /* Subroutine */ int zsteqr_(char *, integer *, doublereal *,
|
|
doublereal *, doublecomplex *, integer *, doublereal *, integer *,
|
|
ftnlen);
|
|
|
|
|
|
/* -- LAPACK computational routine -- */
|
|
/* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
|
|
/* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
|
|
|
|
/* .. Scalar Arguments .. */
|
|
/* .. */
|
|
/* .. Array Arguments .. */
|
|
/* .. */
|
|
|
|
/* ===================================================================== */
|
|
|
|
/* .. Parameters .. */
|
|
/* .. */
|
|
/* .. Local Scalars .. */
|
|
/* .. */
|
|
/* .. External Functions .. */
|
|
/* .. */
|
|
/* .. External Subroutines .. */
|
|
/* .. */
|
|
/* .. Intrinsic Functions .. */
|
|
/* .. */
|
|
/* .. Executable Statements .. */
|
|
|
|
/* Test the input parameters. */
|
|
|
|
/* Parameter adjustments */
|
|
--d__;
|
|
--e;
|
|
z_dim1 = *ldz;
|
|
z_offset = 1 + z_dim1;
|
|
z__ -= z_offset;
|
|
--work;
|
|
--rwork;
|
|
--iwork;
|
|
|
|
/* Function Body */
|
|
*info = 0;
|
|
lquery = *lwork == -1 || *lrwork == -1 || *liwork == -1;
|
|
|
|
if (lsame_(compz, (char *)"N", (ftnlen)1, (ftnlen)1)) {
|
|
icompz = 0;
|
|
} else if (lsame_(compz, (char *)"V", (ftnlen)1, (ftnlen)1)) {
|
|
icompz = 1;
|
|
} else if (lsame_(compz, (char *)"I", (ftnlen)1, (ftnlen)1)) {
|
|
icompz = 2;
|
|
} else {
|
|
icompz = -1;
|
|
}
|
|
if (icompz < 0) {
|
|
*info = -1;
|
|
} else if (*n < 0) {
|
|
*info = -2;
|
|
} else if (*ldz < 1 || icompz > 0 && *ldz < max(1,*n)) {
|
|
*info = -6;
|
|
}
|
|
|
|
if (*info == 0) {
|
|
|
|
/* Compute the workspace requirements */
|
|
|
|
smlsiz = ilaenv_(&c__9, (char *)"ZSTEDC", (char *)" ", &c__0, &c__0, &c__0, &c__0, (
|
|
ftnlen)6, (ftnlen)1);
|
|
if (*n <= 1 || icompz == 0) {
|
|
lwmin = 1;
|
|
liwmin = 1;
|
|
lrwmin = 1;
|
|
} else if (*n <= smlsiz) {
|
|
lwmin = 1;
|
|
liwmin = 1;
|
|
lrwmin = *n - 1 << 1;
|
|
} else if (icompz == 1) {
|
|
lgn = (integer) (log((doublereal) (*n)) / log(2.));
|
|
if (pow_ii(&c__2, &lgn) < *n) {
|
|
++lgn;
|
|
}
|
|
if (pow_ii(&c__2, &lgn) < *n) {
|
|
++lgn;
|
|
}
|
|
lwmin = *n * *n;
|
|
/* Computing 2nd power */
|
|
i__1 = *n;
|
|
lrwmin = *n * 3 + 1 + (*n << 1) * lgn + (i__1 * i__1 << 2);
|
|
liwmin = *n * 6 + 6 + *n * 5 * lgn;
|
|
} else if (icompz == 2) {
|
|
lwmin = 1;
|
|
/* Computing 2nd power */
|
|
i__1 = *n;
|
|
lrwmin = (*n << 2) + 1 + (i__1 * i__1 << 1);
|
|
liwmin = *n * 5 + 3;
|
|
}
|
|
work[1].r = (doublereal) lwmin, work[1].i = 0.;
|
|
rwork[1] = (doublereal) lrwmin;
|
|
iwork[1] = liwmin;
|
|
|
|
if (*lwork < lwmin && ! lquery) {
|
|
*info = -8;
|
|
} else if (*lrwork < lrwmin && ! lquery) {
|
|
*info = -10;
|
|
} else if (*liwork < liwmin && ! lquery) {
|
|
*info = -12;
|
|
}
|
|
}
|
|
|
|
if (*info != 0) {
|
|
i__1 = -(*info);
|
|
xerbla_((char *)"ZSTEDC", &i__1, (ftnlen)6);
|
|
return 0;
|
|
} else if (lquery) {
|
|
return 0;
|
|
}
|
|
|
|
/* Quick return if possible */
|
|
|
|
if (*n == 0) {
|
|
return 0;
|
|
}
|
|
if (*n == 1) {
|
|
if (icompz != 0) {
|
|
i__1 = z_dim1 + 1;
|
|
z__[i__1].r = 1., z__[i__1].i = 0.;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* If the following conditional clause is removed, then the routine */
|
|
/* will use the Divide and Conquer routine to compute only the */
|
|
/* eigenvalues, which requires (3N + 3N**2) real workspace and */
|
|
/* (2 + 5N + 2N lg(N)) integer workspace. */
|
|
/* Since on many architectures DSTERF is much faster than any other */
|
|
/* algorithm for finding eigenvalues only, it is used here */
|
|
/* as the default. If the conditional clause is removed, then */
|
|
/* information on the size of workspace needs to be changed. */
|
|
|
|
/* If COMPZ = 'N', use DSTERF to compute the eigenvalues. */
|
|
|
|
if (icompz == 0) {
|
|
dsterf_(n, &d__[1], &e[1], info);
|
|
goto L70;
|
|
}
|
|
|
|
/* If N is smaller than the minimum divide size (SMLSIZ+1), then */
|
|
/* solve the problem with another solver. */
|
|
|
|
if (*n <= smlsiz) {
|
|
|
|
zsteqr_(compz, n, &d__[1], &e[1], &z__[z_offset], ldz, &rwork[1],
|
|
info, (ftnlen)1);
|
|
|
|
} else {
|
|
|
|
/* If COMPZ = 'I', we simply call DSTEDC instead. */
|
|
|
|
if (icompz == 2) {
|
|
dlaset_((char *)"Full", n, n, &c_b17, &c_b18, &rwork[1], n, (ftnlen)4);
|
|
ll = *n * *n + 1;
|
|
i__1 = *lrwork - ll + 1;
|
|
dstedc_((char *)"I", n, &d__[1], &e[1], &rwork[1], n, &rwork[ll], &i__1, &
|
|
iwork[1], liwork, info, (ftnlen)1);
|
|
i__1 = *n;
|
|
for (j = 1; j <= i__1; ++j) {
|
|
i__2 = *n;
|
|
for (i__ = 1; i__ <= i__2; ++i__) {
|
|
i__3 = i__ + j * z_dim1;
|
|
i__4 = (j - 1) * *n + i__;
|
|
z__[i__3].r = rwork[i__4], z__[i__3].i = 0.;
|
|
/* L10: */
|
|
}
|
|
/* L20: */
|
|
}
|
|
goto L70;
|
|
}
|
|
|
|
/* From now on, only option left to be handled is COMPZ = 'V', */
|
|
/* i.e. ICOMPZ = 1. */
|
|
|
|
/* Scale. */
|
|
|
|
orgnrm = dlanst_((char *)"M", n, &d__[1], &e[1], (ftnlen)1);
|
|
if (orgnrm == 0.) {
|
|
goto L70;
|
|
}
|
|
|
|
eps = dlamch_((char *)"Epsilon", (ftnlen)7);
|
|
|
|
start = 1;
|
|
|
|
/* while ( START <= N ) */
|
|
|
|
L30:
|
|
if (start <= *n) {
|
|
|
|
/* Let FINISH be the position of the next subdiagonal entry */
|
|
/* such that E( FINISH ) <= TINY or FINISH = N if no such */
|
|
/* subdiagonal exists. The matrix identified by the elements */
|
|
/* between START and FINISH constitutes an independent */
|
|
/* sub-problem. */
|
|
|
|
finish = start;
|
|
L40:
|
|
if (finish < *n) {
|
|
tiny = eps * sqrt((d__1 = d__[finish], abs(d__1))) * sqrt((
|
|
d__2 = d__[finish + 1], abs(d__2)));
|
|
if ((d__1 = e[finish], abs(d__1)) > tiny) {
|
|
++finish;
|
|
goto L40;
|
|
}
|
|
}
|
|
|
|
/* (Sub) Problem determined. Compute its size and solve it. */
|
|
|
|
m = finish - start + 1;
|
|
if (m > smlsiz) {
|
|
|
|
/* Scale. */
|
|
|
|
orgnrm = dlanst_((char *)"M", &m, &d__[start], &e[start], (ftnlen)1);
|
|
dlascl_((char *)"G", &c__0, &c__0, &orgnrm, &c_b18, &m, &c__1, &d__[
|
|
start], &m, info, (ftnlen)1);
|
|
i__1 = m - 1;
|
|
i__2 = m - 1;
|
|
dlascl_((char *)"G", &c__0, &c__0, &orgnrm, &c_b18, &i__1, &c__1, &e[
|
|
start], &i__2, info, (ftnlen)1);
|
|
|
|
zlaed0_(n, &m, &d__[start], &e[start], &z__[start * z_dim1 +
|
|
1], ldz, &work[1], n, &rwork[1], &iwork[1], info);
|
|
if (*info > 0) {
|
|
*info = (*info / (m + 1) + start - 1) * (*n + 1) + *info %
|
|
(m + 1) + start - 1;
|
|
goto L70;
|
|
}
|
|
|
|
/* Scale back. */
|
|
|
|
dlascl_((char *)"G", &c__0, &c__0, &c_b18, &orgnrm, &m, &c__1, &d__[
|
|
start], &m, info, (ftnlen)1);
|
|
|
|
} else {
|
|
dsteqr_((char *)"I", &m, &d__[start], &e[start], &rwork[1], &m, &
|
|
rwork[m * m + 1], info, (ftnlen)1);
|
|
zlacrm_(n, &m, &z__[start * z_dim1 + 1], ldz, &rwork[1], &m, &
|
|
work[1], n, &rwork[m * m + 1]);
|
|
zlacpy_((char *)"A", n, &m, &work[1], n, &z__[start * z_dim1 + 1],
|
|
ldz, (ftnlen)1);
|
|
if (*info > 0) {
|
|
*info = start * (*n + 1) + finish;
|
|
goto L70;
|
|
}
|
|
}
|
|
|
|
start = finish + 1;
|
|
goto L30;
|
|
}
|
|
|
|
/* endwhile */
|
|
|
|
|
|
/* Use Selection Sort to minimize swaps of eigenvectors */
|
|
|
|
i__1 = *n;
|
|
for (ii = 2; ii <= i__1; ++ii) {
|
|
i__ = ii - 1;
|
|
k = i__;
|
|
p = d__[i__];
|
|
i__2 = *n;
|
|
for (j = ii; j <= i__2; ++j) {
|
|
if (d__[j] < p) {
|
|
k = j;
|
|
p = d__[j];
|
|
}
|
|
/* L50: */
|
|
}
|
|
if (k != i__) {
|
|
d__[k] = d__[i__];
|
|
d__[i__] = p;
|
|
zswap_(n, &z__[i__ * z_dim1 + 1], &c__1, &z__[k * z_dim1 + 1],
|
|
&c__1);
|
|
}
|
|
/* L60: */
|
|
}
|
|
}
|
|
|
|
L70:
|
|
work[1].r = (doublereal) lwmin, work[1].i = 0.;
|
|
rwork[1] = (doublereal) lrwmin;
|
|
iwork[1] = liwmin;
|
|
|
|
return 0;
|
|
|
|
/* End of ZSTEDC */
|
|
|
|
} /* zstedc_ */
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|