/* Subroutine */
int chbgv_(char *jobz, char *uplo, integer *n, integer *ka, integer *kb, complex *ab, integer *ldab, complex *bb, integer *ldbb, real *w, complex *z__, integer *ldz, complex *work, real *rwork, integer *info)
{
/* System generated locals */
integer ab_dim1, ab_offset, bb_dim1, bb_offset, z_dim1, z_offset, i__1;
/* Local variables */
integer inde;
char vect[1];
extern logical lsame_(char *, char *);
integer iinfo;
logical upper, wantz;
extern /* Subroutine */
int chbtrd_(char *, char *, integer *, integer *, complex *, integer *, real *, real *, complex *, integer *, complex *, integer *), chbgst_(char *, char *, integer *, integer *, integer *, complex *, integer *, complex *, integer *, complex *, integer *, complex *, real *, integer *), xerbla_(char *, integer *), cpbstf_(char *, integer *, integer *, complex *, integer *, integer *);
integer indwrk;
extern /* Subroutine */
int csteqr_(char *, integer *, real *, real *, complex *, integer *, real *, integer *), ssterf_(integer *, real *, real *, integer *);
/* -- LAPACK driver routine (version 3.4.0) -- */
/* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
/* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
/* November 2011 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* ===================================================================== */
/* .. Local Scalars .. */
/* .. */
/* .. External Functions .. */
/* .. */
/* .. External Subroutines .. */
/* .. */
/* .. Executable Statements .. */
/* Test the input parameters. */
/* Parameter adjustments */
ab_dim1 = *ldab;
ab_offset = 1 + ab_dim1;
ab -= ab_offset;
bb_dim1 = *ldbb;
bb_offset = 1 + bb_dim1;
bb -= bb_offset;
--w;
z_dim1 = *ldz;
z_offset = 1 + z_dim1;
z__ -= z_offset;
--work;
--rwork;
/* Function Body */
wantz = lsame_(jobz, "V");
upper = lsame_(uplo, "U");
*info = 0;
if (! (wantz || lsame_(jobz, "N")))
{
*info = -1;
}
else if (! (upper || lsame_(uplo, "L")))
{
*info = -2;
}
else if (*n < 0)
{
*info = -3;
}
else if (*ka < 0)
{
*info = -4;
}
else if (*kb < 0 || *kb > *ka)
{
*info = -5;
}
else if (*ldab < *ka + 1)
{
*info = -7;
}
else if (*ldbb < *kb + 1)
{
*info = -9;
}
else if (*ldz < 1 || wantz && *ldz < *n)
{
*info = -12;
}
if (*info != 0)
{
i__1 = -(*info);
xerbla_("CHBGV ", &i__1);
return 0;
}
/* Quick return if possible */
if (*n == 0)
{
return 0;
}
/* Form a split Cholesky factorization of B. */
cpbstf_(uplo, n, kb, &bb[bb_offset], ldbb, info);
if (*info != 0)
{
*info = *n + *info;
return 0;
}
/* Transform problem to standard eigenvalue problem. */
inde = 1;
indwrk = inde + *n;
chbgst_(jobz, uplo, n, ka, kb, &ab[ab_offset], ldab, &bb[bb_offset], ldbb, &z__[z_offset], ldz, &work[1], &rwork[indwrk], &iinfo);
/* Reduce to tridiagonal form. */
if (wantz)
{
*(unsigned char *)vect = 'U';
}
else
{
*(unsigned char *)vect = 'N';
}
chbtrd_(vect, uplo, n, ka, &ab[ab_offset], ldab, &w[1], &rwork[inde], & z__[z_offset], ldz, &work[1], &iinfo);
/* For eigenvalues only, call SSTERF. For eigenvectors, call CSTEQR. */
if (! wantz)
{
ssterf_(n, &w[1], &rwork[inde], info);
}
else
{
csteqr_(jobz, n, &w[1], &rwork[inde], &z__[z_offset], ldz, &rwork[ indwrk], info);
}
return 0;
/* End of CHBGV */
}
/* Subroutine */
int chbgvd_(char *jobz, char *uplo, integer *n, integer *ka, integer *kb, complex *ab, integer *ldab, complex *bb, integer *ldbb, real *w, complex *z__, integer *ldz, complex *work, integer *lwork, real *rwork, integer *lrwork, integer *iwork, integer *liwork, integer *info)
{
/* System generated locals */
integer ab_dim1, ab_offset, bb_dim1, bb_offset, z_dim1, z_offset, i__1;
/* Local variables */
integer inde;
char vect[1];
integer llwk2;
extern /* Subroutine */
int cgemm_(char *, char *, integer *, integer *, integer *, complex *, complex *, integer *, complex *, integer *, complex *, complex *, integer *);
extern logical lsame_(char *, char *);
integer iinfo, lwmin;
logical upper;
integer llrwk;
logical wantz;
integer indwk2;
extern /* Subroutine */
int cstedc_(char *, integer *, real *, real *, complex *, integer *, complex *, integer *, real *, integer *, integer *, integer *, integer *), chbtrd_(char *, char *, integer *, integer *, complex *, integer *, real *, real *, complex *, integer *, complex *, integer *), chbgst_(char *, char *, integer *, integer *, integer *, complex * , integer *, complex *, integer *, complex *, integer *, complex * , real *, integer *), clacpy_(char *, integer *, integer *, complex *, integer *, complex *, integer *), xerbla_(char *, integer *), cpbstf_(char *, integer *, integer *, complex *, integer *, integer *);
integer indwrk, liwmin;
extern /* Subroutine */
int ssterf_(integer *, real *, real *, integer *);
integer lrwmin;
logical lquery;
/* -- LAPACK driver routine (version 3.4.0) -- */
/* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
/* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
/* November 2011 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* ===================================================================== */
/* .. Parameters .. */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. External Functions .. */
/* .. */
/* .. External Subroutines .. */
/* .. */
/* .. Executable Statements .. */
/* Test the input parameters. */
/* Parameter adjustments */
ab_dim1 = *ldab;
ab_offset = 1 + ab_dim1;
ab -= ab_offset;
bb_dim1 = *ldbb;
bb_offset = 1 + bb_dim1;
bb -= bb_offset;
--w;
z_dim1 = *ldz;
z_offset = 1 + z_dim1;
z__ -= z_offset;
--work;
--rwork;
--iwork;
/* Function Body */
wantz = lsame_(jobz, "V");
upper = lsame_(uplo, "U");
lquery = *lwork == -1 || *lrwork == -1 || *liwork == -1;
*info = 0;
if (*n <= 1)
{
lwmin = *n + 1;
lrwmin = *n + 1;
liwmin = 1;
}
else if (wantz)
{
/* Computing 2nd power */
i__1 = *n;
lwmin = i__1 * i__1 << 1;
/* Computing 2nd power */
i__1 = *n;
lrwmin = *n * 5 + 1 + (i__1 * i__1 << 1);
liwmin = *n * 5 + 3;
}
else
{
lwmin = *n;
lrwmin = *n;
liwmin = 1;
}
if (! (wantz || lsame_(jobz, "N")))
{
*info = -1;
}
else if (! (upper || lsame_(uplo, "L")))
{
*info = -2;
}
else if (*n < 0)
{
*info = -3;
}
else if (*ka < 0)
{
*info = -4;
}
else if (*kb < 0 || *kb > *ka)
{
*info = -5;
}
else if (*ldab < *ka + 1)
{
*info = -7;
}
else if (*ldbb < *kb + 1)
{
*info = -9;
}
else if (*ldz < 1 || wantz && *ldz < *n)
{
*info = -12;
}
if (*info == 0)
{
work[1].r = (real) lwmin;
work[1].i = 0.f; // , expr subst
rwork[1] = (real) lrwmin;
iwork[1] = liwmin;
if (*lwork < lwmin && ! lquery)
{
*info = -14;
}
else if (*lrwork < lrwmin && ! lquery)
{
*info = -16;
}
else if (*liwork < liwmin && ! lquery)
{
*info = -18;
}
}
if (*info != 0)
{
i__1 = -(*info);
xerbla_("CHBGVD", &i__1);
return 0;
}
else if (lquery)
{
return 0;
}
/* Quick return if possible */
if (*n == 0)
{
return 0;
}
/* Form a split Cholesky factorization of B. */
cpbstf_(uplo, n, kb, &bb[bb_offset], ldbb, info);
if (*info != 0)
{
*info = *n + *info;
return 0;
}
/* Transform problem to standard eigenvalue problem. */
inde = 1;
indwrk = inde + *n;
indwk2 = *n * *n + 1;
llwk2 = *lwork - indwk2 + 2;
llrwk = *lrwork - indwrk + 2;
chbgst_(jobz, uplo, n, ka, kb, &ab[ab_offset], ldab, &bb[bb_offset], ldbb, &z__[z_offset], ldz, &work[1], &rwork[indwrk], &iinfo);
/* Reduce Hermitian band matrix to tridiagonal form. */
if (wantz)
{
*(unsigned char *)vect = 'U';
}
else
{
*(unsigned char *)vect = 'N';
}
chbtrd_(vect, uplo, n, ka, &ab[ab_offset], ldab, &w[1], &rwork[inde], & z__[z_offset], ldz, &work[1], &iinfo);
/* For eigenvalues only, call SSTERF. For eigenvectors, call CSTEDC. */
if (! wantz)
{
ssterf_(n, &w[1], &rwork[inde], info);
}
else
{
cstedc_("I", n, &w[1], &rwork[inde], &work[1], n, &work[indwk2], & llwk2, &rwork[indwrk], &llrwk, &iwork[1], liwork, info);
cgemm_("N", "N", n, n, n, &c_b1, &z__[z_offset], ldz, &work[1], n, & c_b2, &work[indwk2], n);
clacpy_("A", n, n, &work[indwk2], n, &z__[z_offset], ldz);
}
work[1].r = (real) lwmin;
work[1].i = 0.f; // , expr subst
rwork[1] = (real) lrwmin;
iwork[1] = liwmin;
return 0;
/* End of CHBGVD */
}
/* Subroutine */ int chbgvd_(char *jobz, char *uplo, integer *n, integer *ka,
integer *kb, complex *ab, integer *ldab, complex *bb, integer *ldbb,
real *w, complex *z__, integer *ldz, complex *work, integer *lwork,
real *rwork, integer *lrwork, integer *iwork, integer *liwork,
integer *info)
{
/* System generated locals */
integer ab_dim1, ab_offset, bb_dim1, bb_offset, z_dim1, z_offset, i__1;
/* Local variables */
integer inde;
char vect[1];
integer llwk2;
integer iinfo, lwmin;
logical upper;
integer llrwk;
logical wantz;
integer indwk2;
integer indwrk, liwmin;
integer lrwmin;
logical lquery;
/* -- LAPACK driver routine (version 3.2) -- */
/* November 2006 */
/* Purpose */
/* ======= */
/* CHBGVD computes all the eigenvalues, and optionally, the eigenvectors */
/* of a complex generalized Hermitian-definite banded eigenproblem, of */
/* the form A*x=(lambda)*B*x. Here A and B are assumed to be Hermitian */
/* and banded, and B is also positive definite. If eigenvectors are */
/* desired, it uses a divide and conquer algorithm. */
/* The divide and conquer algorithm 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. */
/* Arguments */
/* ========= */
/* JOBZ (input) CHARACTER*1 */
/* = 'N': Compute eigenvalues only; */
/* = 'V': Compute eigenvalues and eigenvectors. */
/* UPLO (input) CHARACTER*1 */
/* = 'U': Upper triangles of A and B are stored; */
/* = 'L': Lower triangles of A and B are stored. */
/* N (input) INTEGER */
/* The order of the matrices A and B. N >= 0. */
/* KA (input) INTEGER */
/* The number of superdiagonals of the matrix A if UPLO = 'U', */
/* or the number of subdiagonals if UPLO = 'L'. KA >= 0. */
/* KB (input) INTEGER */
/* The number of superdiagonals of the matrix B if UPLO = 'U', */
/* or the number of subdiagonals if UPLO = 'L'. KB >= 0. */
/* AB (input/output) COMPLEX array, dimension (LDAB, N) */
/* On entry, the upper or lower triangle of the Hermitian band */
/* matrix A, stored in the first ka+1 rows of the array. The */
/* j-th column of A is stored in the j-th column of the array AB */
/* as follows: */
/* if UPLO = 'U', AB(ka+1+i-j,j) = A(i,j) for max(1,j-ka)<=i<=j; */
/* if UPLO = 'L', AB(1+i-j,j) = A(i,j) for j<=i<=min(n,j+ka). */
/* On exit, the contents of AB are destroyed. */
/* LDAB (input) INTEGER */
/* The leading dimension of the array AB. LDAB >= KA+1. */
/* BB (input/output) COMPLEX array, dimension (LDBB, N) */
/* On entry, the upper or lower triangle of the Hermitian band */
/* matrix B, stored in the first kb+1 rows of the array. The */
/* j-th column of B is stored in the j-th column of the array BB */
/* as follows: */
/* if UPLO = 'U', BB(kb+1+i-j,j) = B(i,j) for max(1,j-kb)<=i<=j; */
/* if UPLO = 'L', BB(1+i-j,j) = B(i,j) for j<=i<=min(n,j+kb). */
/* On exit, the factor S from the split Cholesky factorization */
/* B = S**H*S, as returned by CPBSTF. */
/* LDBB (input) INTEGER */
/* The leading dimension of the array BB. LDBB >= KB+1. */
/* W (output) REAL array, dimension (N) */
/* If INFO = 0, the eigenvalues in ascending order. */
/* Z (output) COMPLEX array, dimension (LDZ, N) */
/* If JOBZ = 'V', then if INFO = 0, Z contains the matrix Z of */
/* eigenvectors, with the i-th column of Z holding the */
/* eigenvector associated with W(i). The eigenvectors are */
/* normalized so that Z**H*B*Z = I. */
/* If JOBZ = 'N', then Z is not referenced. */
/* LDZ (input) INTEGER */
/* The leading dimension of the array Z. LDZ >= 1, and if */
/* JOBZ = 'V', LDZ >= N. */
/* WORK (workspace/output) COMPLEX array, dimension (MAX(1,LWORK)) */
/* On exit, if INFO=0, WORK(1) returns the optimal LWORK. */
/* LWORK (input) INTEGER */
/* The dimension of the array WORK. */
/* If N <= 1, LWORK >= 1. */
/* If JOBZ = 'N' and N > 1, LWORK >= N. */
/* If JOBZ = 'V' and N > 1, LWORK >= 2*N**2. */
/* 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. */
/* RWORK (workspace/output) REAL array, dimension (MAX(1,LRWORK)) */
/* On exit, if INFO=0, RWORK(1) returns the optimal LRWORK. */
/* LRWORK (input) INTEGER */
/* The dimension of array RWORK. */
/* If N <= 1, LRWORK >= 1. */
/* If JOBZ = 'N' and N > 1, LRWORK >= N. */
/* If JOBZ = 'V' and N > 1, LRWORK >= 1 + 5*N + 2*N**2. */
/* 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. */
/* IWORK (workspace/output) INTEGER array, dimension (MAX(1,LIWORK)) */
/* On exit, if INFO=0, IWORK(1) returns the optimal LIWORK. */
/* LIWORK (input) INTEGER */
/* The dimension of array IWORK. */
/* If JOBZ = 'N' or N <= 1, LIWORK >= 1. */
/* If JOBZ = 'V' and N > 1, LIWORK >= 3 + 5*N. */
/* 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. */
/* INFO (output) INTEGER */
/* = 0: successful exit */
/* < 0: if INFO = -i, the i-th argument had an illegal value */
/* > 0: if INFO = i, and i is: */
/* <= N: the algorithm failed to converge: */
/* i off-diagonal elements of an intermediate */
/* tridiagonal form did not converge to zero; */
/* > N: if INFO = N + i, for 1 <= i <= N, then CPBSTF */
/* returned INFO = i: B is not positive definite. */
/* The factorization of B could not be completed and */
/* no eigenvalues or eigenvectors were computed. */
/* Further Details */
/* =============== */
/* Based on contributions by */
/* Mark Fahey, Department of Mathematics, Univ. of Kentucky, USA */
/* ===================================================================== */
/* Test the input parameters. */
/* Parameter adjustments */
ab_dim1 = *ldab;
ab_offset = 1 + ab_dim1;
ab -= ab_offset;
bb_dim1 = *ldbb;
bb_offset = 1 + bb_dim1;
bb -= bb_offset;
--w;
z_dim1 = *ldz;
z_offset = 1 + z_dim1;
z__ -= z_offset;
--work;
--rwork;
--iwork;
/* Function Body */
wantz = lsame_(jobz, "V");
upper = lsame_(uplo, "U");
lquery = *lwork == -1 || *lrwork == -1 || *liwork == -1;
*info = 0;
if (*n <= 1) {
lwmin = 1;
lrwmin = 1;
liwmin = 1;
} else if (wantz) {
/* Computing 2nd power */
i__1 = *n;
lwmin = i__1 * i__1 << 1;
/* Computing 2nd power */
i__1 = *n;
lrwmin = *n * 5 + 1 + (i__1 * i__1 << 1);
liwmin = *n * 5 + 3;
} else {
lwmin = *n;
lrwmin = *n;
liwmin = 1;
}
if (! (wantz || lsame_(jobz, "N"))) {
*info = -1;
} else if (! (upper || lsame_(uplo, "L"))) {
*info = -2;
} else if (*n < 0) {
*info = -3;
} else if (*ka < 0) {
*info = -4;
} else if (*kb < 0 || *kb > *ka) {
*info = -5;
} else if (*ldab < *ka + 1) {
*info = -7;
} else if (*ldbb < *kb + 1) {
*info = -9;
} else if (*ldz < 1 || wantz && *ldz < *n) {
*info = -12;
}
if (*info == 0) {
work[1].r = (real) lwmin, work[1].i = 0.f;
rwork[1] = (real) lrwmin;
iwork[1] = liwmin;
if (*lwork < lwmin && ! lquery) {
*info = -14;
} else if (*lrwork < lrwmin && ! lquery) {
*info = -16;
} else if (*liwork < liwmin && ! lquery) {
*info = -18;
}
}
if (*info != 0) {
i__1 = -(*info);
xerbla_("CHBGVD", &i__1);
return 0;
} else if (lquery) {
return 0;
}
/* Quick return if possible */
if (*n == 0) {
return 0;
}
/* Form a split Cholesky factorization of B. */
cpbstf_(uplo, n, kb, &bb[bb_offset], ldbb, info);
if (*info != 0) {
*info = *n + *info;
return 0;
}
/* Transform problem to standard eigenvalue problem. */
inde = 1;
indwrk = inde + *n;
indwk2 = *n * *n + 1;
llwk2 = *lwork - indwk2 + 2;
llrwk = *lrwork - indwrk + 2;
chbgst_(jobz, uplo, n, ka, kb, &ab[ab_offset], ldab, &bb[bb_offset], ldbb,
&z__[z_offset], ldz, &work[1], &rwork[indwrk], &iinfo);
/* Reduce Hermitian band matrix to tridiagonal form. */
if (wantz) {
*(unsigned char *)vect = 'U';
} else {
*(unsigned char *)vect = 'N';
}
chbtrd_(vect, uplo, n, ka, &ab[ab_offset], ldab, &w[1], &rwork[inde], &
z__[z_offset], ldz, &work[1], &iinfo);
/* For eigenvalues only, call SSTERF. For eigenvectors, call CSTEDC. */
if (! wantz) {
ssterf_(n, &w[1], &rwork[inde], info);
} else {
cstedc_("I", n, &w[1], &rwork[inde], &work[1], n, &work[indwk2], &
llwk2, &rwork[indwrk], &llrwk, &iwork[1], liwork, info);
cgemm_("N", "N", n, n, n, &c_b1, &z__[z_offset], ldz, &work[1], n, &
c_b2, &work[indwk2], n);
clacpy_("A", n, n, &work[indwk2], n, &z__[z_offset], ldz);
}
work[1].r = (real) lwmin, work[1].i = 0.f;
rwork[1] = (real) lrwmin;
iwork[1] = liwmin;
return 0;
/* End of CHBGVD */
} /* chbgvd_ */
/* Subroutine */
int chbgvx_(char *jobz, char *range, char *uplo, integer *n, integer *ka, integer *kb, complex *ab, integer *ldab, complex *bb, integer *ldbb, complex *q, integer *ldq, real *vl, real *vu, integer * il, integer *iu, real *abstol, integer *m, real *w, complex *z__, integer *ldz, complex *work, real *rwork, integer *iwork, integer * ifail, integer *info)
{
/* System generated locals */
integer ab_dim1, ab_offset, bb_dim1, bb_offset, q_dim1, q_offset, z_dim1, z_offset, i__1, i__2;
/* Local variables */
integer i__, j, jj;
real tmp1;
integer indd, inde;
char vect[1];
logical test;
integer itmp1, indee;
extern logical lsame_(char *, char *);
extern /* Subroutine */
int cgemv_(char *, integer *, integer *, complex * , complex *, integer *, complex *, integer *, complex *, complex * , integer *);
integer iinfo;
char order[1];
extern /* Subroutine */
int ccopy_(integer *, complex *, integer *, complex *, integer *), cswap_(integer *, complex *, integer *, complex *, integer *);
logical upper;
extern /* Subroutine */
int scopy_(integer *, real *, integer *, real *, integer *);
logical wantz, alleig, indeig;
integer indibl;
extern /* Subroutine */
int chbtrd_(char *, char *, integer *, integer *, complex *, integer *, real *, real *, complex *, integer *, complex *, integer *);
logical valeig;
extern /* Subroutine */
int chbgst_(char *, char *, integer *, integer *, integer *, complex *, integer *, complex *, integer *, complex *, integer *, complex *, real *, integer *), clacpy_( char *, integer *, integer *, complex *, integer *, complex *, integer *), xerbla_(char *, integer *), cpbstf_( char *, integer *, integer *, complex *, integer *, integer *);
integer indiwk, indisp;
extern /* Subroutine */
int cstein_(integer *, real *, real *, integer *, real *, integer *, integer *, complex *, integer *, real *, integer *, integer *, integer *);
integer indrwk, indwrk;
extern /* Subroutine */
int csteqr_(char *, integer *, real *, real *, complex *, integer *, real *, integer *), ssterf_(integer *, real *, real *, integer *);
integer nsplit;
extern /* Subroutine */
int sstebz_(char *, char *, integer *, real *, real *, integer *, integer *, real *, real *, real *, integer *, integer *, real *, integer *, integer *, real *, integer *, integer *);
/* -- LAPACK driver routine (version 3.4.0) -- */
/* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
/* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
/* November 2011 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* ===================================================================== */
/* .. Parameters .. */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. External Functions .. */
/* .. */
/* .. External Subroutines .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* .. Executable Statements .. */
/* Test the input parameters. */
/* Parameter adjustments */
ab_dim1 = *ldab;
ab_offset = 1 + ab_dim1;
ab -= ab_offset;
bb_dim1 = *ldbb;
bb_offset = 1 + bb_dim1;
bb -= bb_offset;
q_dim1 = *ldq;
q_offset = 1 + q_dim1;
q -= q_offset;
--w;
z_dim1 = *ldz;
z_offset = 1 + z_dim1;
z__ -= z_offset;
--work;
--rwork;
--iwork;
--ifail;
/* Function Body */
wantz = lsame_(jobz, "V");
upper = lsame_(uplo, "U");
alleig = lsame_(range, "A");
valeig = lsame_(range, "V");
indeig = lsame_(range, "I");
*info = 0;
if (! (wantz || lsame_(jobz, "N")))
{
*info = -1;
}
else if (! (alleig || valeig || indeig))
{
*info = -2;
}
else if (! (upper || lsame_(uplo, "L")))
{
*info = -3;
}
else if (*n < 0)
{
*info = -4;
}
else if (*ka < 0)
{
*info = -5;
}
else if (*kb < 0 || *kb > *ka)
{
*info = -6;
}
else if (*ldab < *ka + 1)
{
*info = -8;
}
else if (*ldbb < *kb + 1)
{
*info = -10;
}
else if (*ldq < 1 || wantz && *ldq < *n)
{
*info = -12;
}
else
{
if (valeig)
{
if (*n > 0 && *vu <= *vl)
{
*info = -14;
}
}
else if (indeig)
{
if (*il < 1 || *il > max(1,*n))
{
*info = -15;
}
else if (*iu < min(*n,*il) || *iu > *n)
{
*info = -16;
}
}
}
if (*info == 0)
{
if (*ldz < 1 || wantz && *ldz < *n)
{
*info = -21;
}
}
if (*info != 0)
{
i__1 = -(*info);
xerbla_("CHBGVX", &i__1);
return 0;
}
/* Quick return if possible */
*m = 0;
if (*n == 0)
{
return 0;
}
/* Form a split Cholesky factorization of B. */
cpbstf_(uplo, n, kb, &bb[bb_offset], ldbb, info);
if (*info != 0)
{
*info = *n + *info;
return 0;
}
/* Transform problem to standard eigenvalue problem. */
chbgst_(jobz, uplo, n, ka, kb, &ab[ab_offset], ldab, &bb[bb_offset], ldbb, &q[q_offset], ldq, &work[1], &rwork[1], &iinfo);
/* Solve the standard eigenvalue problem. */
/* Reduce Hermitian band matrix to tridiagonal form. */
indd = 1;
inde = indd + *n;
indrwk = inde + *n;
indwrk = 1;
if (wantz)
{
*(unsigned char *)vect = 'U';
}
else
{
*(unsigned char *)vect = 'N';
}
chbtrd_(vect, uplo, n, ka, &ab[ab_offset], ldab, &rwork[indd], &rwork[ inde], &q[q_offset], ldq, &work[indwrk], &iinfo);
/* If all eigenvalues are desired and ABSTOL is less than or equal */
/* to zero, then call SSTERF or CSTEQR. If this fails for some */
/* eigenvalue, then try SSTEBZ. */
test = FALSE_;
if (indeig)
{
if (*il == 1 && *iu == *n)
{
test = TRUE_;
}
}
if ((alleig || test) && *abstol <= 0.f)
{
scopy_(n, &rwork[indd], &c__1, &w[1], &c__1);
indee = indrwk + (*n << 1);
i__1 = *n - 1;
scopy_(&i__1, &rwork[inde], &c__1, &rwork[indee], &c__1);
if (! wantz)
{
ssterf_(n, &w[1], &rwork[indee], info);
}
else
{
clacpy_("A", n, n, &q[q_offset], ldq, &z__[z_offset], ldz);
csteqr_(jobz, n, &w[1], &rwork[indee], &z__[z_offset], ldz, & rwork[indrwk], info);
if (*info == 0)
{
i__1 = *n;
for (i__ = 1;
i__ <= i__1;
++i__)
{
ifail[i__] = 0;
/* L10: */
}
}
}
if (*info == 0)
{
*m = *n;
goto L30;
}
*info = 0;
}
/* Otherwise, call SSTEBZ and, if eigenvectors are desired, */
/* call CSTEIN. */
if (wantz)
{
*(unsigned char *)order = 'B';
}
else
{
*(unsigned char *)order = 'E';
}
indibl = 1;
indisp = indibl + *n;
indiwk = indisp + *n;
sstebz_(range, order, n, vl, vu, il, iu, abstol, &rwork[indd], &rwork[ inde], m, &nsplit, &w[1], &iwork[indibl], &iwork[indisp], &rwork[ indrwk], &iwork[indiwk], info);
if (wantz)
{
cstein_(n, &rwork[indd], &rwork[inde], m, &w[1], &iwork[indibl], & iwork[indisp], &z__[z_offset], ldz, &rwork[indrwk], &iwork[ indiwk], &ifail[1], info);
/* Apply unitary matrix used in reduction to tridiagonal */
/* form to eigenvectors returned by CSTEIN. */
i__1 = *m;
for (j = 1;
j <= i__1;
++j)
{
ccopy_(n, &z__[j * z_dim1 + 1], &c__1, &work[1], &c__1);
cgemv_("N", n, n, &c_b2, &q[q_offset], ldq, &work[1], &c__1, & c_b1, &z__[j * z_dim1 + 1], &c__1);
/* L20: */
}
}
L30: /* If eigenvalues are not in order, then sort them, along with */
/* eigenvectors. */
if (wantz)
{
i__1 = *m - 1;
for (j = 1;
j <= i__1;
++j)
{
i__ = 0;
tmp1 = w[j];
i__2 = *m;
for (jj = j + 1;
jj <= i__2;
++jj)
{
if (w[jj] < tmp1)
{
i__ = jj;
tmp1 = w[jj];
}
/* L40: */
}
if (i__ != 0)
{
itmp1 = iwork[indibl + i__ - 1];
w[i__] = w[j];
iwork[indibl + i__ - 1] = iwork[indibl + j - 1];
w[j] = tmp1;
iwork[indibl + j - 1] = itmp1;
cswap_(n, &z__[i__ * z_dim1 + 1], &c__1, &z__[j * z_dim1 + 1], &c__1);
if (*info != 0)
{
itmp1 = ifail[i__];
ifail[i__] = ifail[j];
ifail[j] = itmp1;
}
}
/* L50: */
}
}
return 0;
/* End of CHBGVX */
}
/* Subroutine */ int chbgv_(char *jobz, char *uplo, integer *n, integer *ka,
integer *kb, complex *ab, integer *ldab, complex *bb, integer *ldbb,
real *w, complex *z, integer *ldz, complex *work, real *rwork,
integer *info)
{
/* -- LAPACK driver routine (version 2.0) --
Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
Courant Institute, Argonne National Lab, and Rice University
September 30, 1994
Purpose
=======
CHBGV computes all the eigenvalues, and optionally, the eigenvectors
of a complex generalized Hermitian-definite banded eigenproblem, of
the form A*x=(lambda)*B*x. Here A and B are assumed to be Hermitian
and banded, and B is also positive definite.
Arguments
=========
JOBZ (input) CHARACTER*1
= 'N': Compute eigenvalues only;
= 'V': Compute eigenvalues and eigenvectors.
UPLO (input) CHARACTER*1
= 'U': Upper triangles of A and B are stored;
= 'L': Lower triangles of A and B are stored.
N (input) INTEGER
The order of the matrices A and B. N >= 0.
KA (input) INTEGER
The number of superdiagonals of the matrix A if UPLO = 'U',
or the number of subdiagonals if UPLO = 'L'. KA >= 0.
KB (input) INTEGER
The number of superdiagonals of the matrix B if UPLO = 'U',
or the number of subdiagonals if UPLO = 'L'. KB >= 0.
AB (input/output) COMPLEX array, dimension (LDAB, N)
On entry, the upper or lower triangle of the Hermitian band
matrix A, stored in the first ka+1 rows of the array. The
j-th column of A is stored in the j-th column of the array AB
as follows:
if UPLO = 'U', AB(ka+1+i-j,j) = A(i,j) for max(1,j-ka)<=i<=j;
if UPLO = 'L', AB(1+i-j,j) = A(i,j) for j<=i<=min(n,j+ka).
On exit, the contents of AB are destroyed.
LDAB (input) INTEGER
The leading dimension of the array AB. LDAB >= KA+1.
BB (input/output) COMPLEX array, dimension (LDBB, N)
On entry, the upper or lower triangle of the Hermitian band
matrix B, stored in the first kb+1 rows of the array. The
j-th column of B is stored in the j-th column of the array BB
as follows:
if UPLO = 'U', BB(kb+1+i-j,j) = B(i,j) for max(1,j-kb)<=i<=j;
if UPLO = 'L', BB(1+i-j,j) = B(i,j) for j<=i<=min(n,j+kb).
On exit, the factor S from the split Cholesky factorization
B = S**H*S, as returned by CPBSTF.
LDBB (input) INTEGER
The leading dimension of the array BB. LDBB >= KB+1.
W (output) REAL array, dimension (N)
If INFO = 0, the eigenvalues in ascending order.
Z (output) COMPLEX array, dimension (LDZ, N)
If JOBZ = 'V', then if INFO = 0, Z contains the matrix Z of
eigenvectors, with the i-th column of Z holding the
eigenvector associated with W(i). The eigenvectors are
normalized so that Z**H*B*Z = I.
If JOBZ = 'N', then Z is not referenced.
LDZ (input) INTEGER
The leading dimension of the array Z. LDZ >= 1, and if
JOBZ = 'V', LDZ >= N.
WORK (workspace) COMPLEX array, dimension (N)
RWORK (workspace) REAL array, dimension (3*N)
INFO (output) INTEGER
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value
> 0: if INFO = i, and i is:
<= N: the algorithm failed to converge:
i off-diagonal elements of an intermediate
tridiagonal form did not converge to zero;
> N: if INFO = N + i, for 1 <= i <= N, then CPBSTF
returned INFO = i: B is not positive definite.
The factorization of B could not be completed and
no eigenvalues or eigenvectors were computed.
=====================================================================
Test the input parameters.
Parameter adjustments
Function Body */
/* System generated locals */
integer ab_dim1, ab_offset, bb_dim1, bb_offset, z_dim1, z_offset, i__1;
/* Local variables */
static integer inde;
static char vect[1];
extern logical lsame_(char *, char *);
static integer iinfo;
static logical upper, wantz;
extern /* Subroutine */ int chbtrd_(char *, char *, integer *, integer *,
complex *, integer *, real *, real *, complex *, integer *,
complex *, integer *), chbgst_(char *, char *,
integer *, integer *, integer *, complex *, integer *, complex *,
integer *, complex *, integer *, complex *, real *, integer *), xerbla_(char *, integer *), cpbstf_(char
*, integer *, integer *, complex *, integer *, integer *);
static integer indwrk;
extern /* Subroutine */ int csteqr_(char *, integer *, real *, real *,
complex *, integer *, real *, integer *), ssterf_(integer
*, real *, real *, integer *);
#define W(I) w[(I)-1]
#define WORK(I) work[(I)-1]
#define RWORK(I) rwork[(I)-1]
#define AB(I,J) ab[(I)-1 + ((J)-1)* ( *ldab)]
#define BB(I,J) bb[(I)-1 + ((J)-1)* ( *ldbb)]
#define Z(I,J) z[(I)-1 + ((J)-1)* ( *ldz)]
wantz = lsame_(jobz, "V");
upper = lsame_(uplo, "U");
*info = 0;
if (! (wantz || lsame_(jobz, "N"))) {
*info = -1;
} else if (! (upper || lsame_(uplo, "L"))) {
*info = -2;
} else if (*n < 0) {
*info = -3;
} else if (*ka < 0) {
*info = -4;
} else if (*kb < 0 || *kb > *ka) {
*info = -5;
} else if (*ldab < *ka + 1) {
*info = -7;
} else if (*ldbb < *kb + 1) {
*info = -9;
} else if (*ldz < 1 || wantz && *ldz < *n) {
*info = -12;
}
if (*info != 0) {
i__1 = -(*info);
xerbla_("CHBGV ", &i__1);
return 0;
}
/* Quick return if possible */
if (*n == 0) {
return 0;
}
/* Form a split Cholesky factorization of B. */
cpbstf_(uplo, n, kb, &BB(1,1), ldbb, info);
if (*info != 0) {
*info = *n + *info;
return 0;
}
/* Transform problem to standard eigenvalue problem. */
inde = 1;
indwrk = inde + *n;
chbgst_(jobz, uplo, n, ka, kb, &AB(1,1), ldab, &BB(1,1), ldbb,
&Z(1,1), ldz, &WORK(1), &RWORK(indwrk), &iinfo);
/* Reduce to tridiagonal form. */
if (wantz) {
*(unsigned char *)vect = 'U';
} else {
*(unsigned char *)vect = 'N';
}
chbtrd_(vect, uplo, n, ka, &AB(1,1), ldab, &W(1), &RWORK(inde), &Z(1,1), ldz, &WORK(1), &iinfo);
/* For eigenvalues only, call SSTERF. For eigenvectors, call CSTEQR.
*/
if (! wantz) {
ssterf_(n, &W(1), &RWORK(inde), info);
} else {
csteqr_(jobz, n, &W(1), &RWORK(inde), &Z(1,1), ldz, &RWORK(
indwrk), info);
}
return 0;
/* End of CHBGV */
} /* chbgv_ */
/* Subroutine */ int chbgvx_(char *jobz, char *range, char *uplo, integer *n,
integer *ka, integer *kb, complex *ab, integer *ldab, complex *bb,
integer *ldbb, complex *q, integer *ldq, real *vl, real *vu, integer *
il, integer *iu, real *abstol, integer *m, real *w, complex *z__,
integer *ldz, complex *work, real *rwork, integer *iwork, integer *
ifail, integer *info)
{
/* System generated locals */
integer ab_dim1, ab_offset, bb_dim1, bb_offset, q_dim1, q_offset, z_dim1,
z_offset, i__1, i__2;
/* Local variables */
integer i__, j, jj;
real tmp1;
integer indd, inde;
char vect[1];
logical test;
integer itmp1, indee;
extern logical lsame_(char *, char *);
extern /* Subroutine */ int cgemv_(char *, integer *, integer *, complex *
, complex *, integer *, complex *, integer *, complex *, complex *
, integer *);
integer iinfo;
char order[1];
extern /* Subroutine */ int ccopy_(integer *, complex *, integer *,
complex *, integer *), cswap_(integer *, complex *, integer *,
complex *, integer *);
logical upper;
extern /* Subroutine */ int scopy_(integer *, real *, integer *, real *,
integer *);
logical wantz, alleig, indeig;
integer indibl;
extern /* Subroutine */ int chbtrd_(char *, char *, integer *, integer *,
complex *, integer *, real *, real *, complex *, integer *,
complex *, integer *);
logical valeig;
extern /* Subroutine */ int chbgst_(char *, char *, integer *, integer *,
integer *, complex *, integer *, complex *, integer *, complex *,
integer *, complex *, real *, integer *), clacpy_(
char *, integer *, integer *, complex *, integer *, complex *,
integer *), xerbla_(char *, integer *), cpbstf_(
char *, integer *, integer *, complex *, integer *, integer *);
integer indiwk, indisp;
extern /* Subroutine */ int cstein_(integer *, real *, real *, integer *,
real *, integer *, integer *, complex *, integer *, real *,
integer *, integer *, integer *);
integer indrwk, indwrk;
extern /* Subroutine */ int csteqr_(char *, integer *, real *, real *,
complex *, integer *, real *, integer *), ssterf_(integer
*, real *, real *, integer *);
integer nsplit;
extern /* Subroutine */ int sstebz_(char *, char *, integer *, real *,
real *, integer *, integer *, real *, real *, real *, integer *,
integer *, real *, integer *, integer *, real *, integer *,
integer *);
/* -- LAPACK driver routine (version 3.2) -- */
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/* November 2006 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* CHBGVX computes all the eigenvalues, and optionally, the eigenvectors */
/* of a complex generalized Hermitian-definite banded eigenproblem, of */
/* the form A*x=(lambda)*B*x. Here A and B are assumed to be Hermitian */
/* and banded, and B is also positive definite. Eigenvalues and */
/* eigenvectors can be selected by specifying either all eigenvalues, */
/* a range of values or a range of indices for the desired eigenvalues. */
/* Arguments */
/* ========= */
/* JOBZ (input) CHARACTER*1 */
/* = 'N': Compute eigenvalues only; */
/* = 'V': Compute eigenvalues and eigenvectors. */
/* RANGE (input) CHARACTER*1 */
/* = 'A': all eigenvalues will be found; */
/* = 'V': all eigenvalues in the half-open interval (VL,VU] */
/* will be found; */
/* = 'I': the IL-th through IU-th eigenvalues will be found. */
/* UPLO (input) CHARACTER*1 */
/* = 'U': Upper triangles of A and B are stored; */
/* = 'L': Lower triangles of A and B are stored. */
/* N (input) INTEGER */
/* The order of the matrices A and B. N >= 0. */
/* KA (input) INTEGER */
/* The number of superdiagonals of the matrix A if UPLO = 'U', */
/* or the number of subdiagonals if UPLO = 'L'. KA >= 0. */
/* KB (input) INTEGER */
/* The number of superdiagonals of the matrix B if UPLO = 'U', */
/* or the number of subdiagonals if UPLO = 'L'. KB >= 0. */
/* AB (input/output) COMPLEX array, dimension (LDAB, N) */
/* On entry, the upper or lower triangle of the Hermitian band */
/* matrix A, stored in the first ka+1 rows of the array. The */
/* j-th column of A is stored in the j-th column of the array AB */
/* as follows: */
/* if UPLO = 'U', AB(ka+1+i-j,j) = A(i,j) for max(1,j-ka)<=i<=j; */
/* if UPLO = 'L', AB(1+i-j,j) = A(i,j) for j<=i<=min(n,j+ka). */
/* On exit, the contents of AB are destroyed. */
/* LDAB (input) INTEGER */
/* The leading dimension of the array AB. LDAB >= KA+1. */
/* BB (input/output) COMPLEX array, dimension (LDBB, N) */
/* On entry, the upper or lower triangle of the Hermitian band */
/* matrix B, stored in the first kb+1 rows of the array. The */
/* j-th column of B is stored in the j-th column of the array BB */
/* as follows: */
/* if UPLO = 'U', BB(kb+1+i-j,j) = B(i,j) for max(1,j-kb)<=i<=j; */
/* if UPLO = 'L', BB(1+i-j,j) = B(i,j) for j<=i<=min(n,j+kb). */
/* On exit, the factor S from the split Cholesky factorization */
/* B = S**H*S, as returned by CPBSTF. */
/* LDBB (input) INTEGER */
/* The leading dimension of the array BB. LDBB >= KB+1. */
/* Q (output) COMPLEX array, dimension (LDQ, N) */
/* If JOBZ = 'V', the n-by-n matrix used in the reduction of */
/* A*x = (lambda)*B*x to standard form, i.e. C*x = (lambda)*x, */
/* and consequently C to tridiagonal form. */
/* If JOBZ = 'N', the array Q is not referenced. */
/* LDQ (input) INTEGER */
/* The leading dimension of the array Q. If JOBZ = 'N', */
/* LDQ >= 1. If JOBZ = 'V', LDQ >= max(1,N). */
/* VL (input) REAL */
/* VU (input) REAL */
/* If RANGE='V', the lower and upper bounds of the interval to */
/* be searched for eigenvalues. VL < VU. */
/* Not referenced if RANGE = 'A' or 'I'. */
/* IL (input) INTEGER */
/* IU (input) INTEGER */
/* If RANGE='I', the indices (in ascending order) of the */
/* smallest and largest eigenvalues to be returned. */
/* 1 <= IL <= IU <= N, if N > 0; IL = 1 and IU = 0 if N = 0. */
/* Not referenced if RANGE = 'A' or 'V'. */
/* ABSTOL (input) REAL */
/* The absolute error tolerance for the eigenvalues. */
/* An approximate eigenvalue is accepted as converged */
/* when it is determined to lie in an interval [a,b] */
/* of width less than or equal to */
/* ABSTOL + EPS * max( |a|,|b| ) , */
/* where EPS is the machine precision. If ABSTOL is less than */
/* or equal to zero, then EPS*|T| will be used in its place, */
/* where |T| is the 1-norm of the tridiagonal matrix obtained */
/* by reducing AP to tridiagonal form. */
/* Eigenvalues will be computed most accurately when ABSTOL is */
/* set to twice the underflow threshold 2*SLAMCH('S'), not zero. */
/* If this routine returns with INFO>0, indicating that some */
/* eigenvectors did not converge, try setting ABSTOL to */
/* 2*SLAMCH('S'). */
/* M (output) INTEGER */
/* The total number of eigenvalues found. 0 <= M <= N. */
/* If RANGE = 'A', M = N, and if RANGE = 'I', M = IU-IL+1. */
/* W (output) REAL array, dimension (N) */
/* If INFO = 0, the eigenvalues in ascending order. */
/* Z (output) COMPLEX array, dimension (LDZ, N) */
/* If JOBZ = 'V', then if INFO = 0, Z contains the matrix Z of */
/* eigenvectors, with the i-th column of Z holding the */
/* eigenvector associated with W(i). The eigenvectors are */
/* normalized so that Z**H*B*Z = I. */
/* If JOBZ = 'N', then Z is not referenced. */
/* LDZ (input) INTEGER */
/* The leading dimension of the array Z. LDZ >= 1, and if */
/* JOBZ = 'V', LDZ >= N. */
/* WORK (workspace) COMPLEX array, dimension (N) */
/* RWORK (workspace) REAL array, dimension (7*N) */
/* IWORK (workspace) INTEGER array, dimension (5*N) */
/* IFAIL (output) INTEGER array, dimension (N) */
/* If JOBZ = 'V', then if INFO = 0, the first M elements of */
/* IFAIL are zero. If INFO > 0, then IFAIL contains the */
/* indices of the eigenvectors that failed to converge. */
/* If JOBZ = 'N', then IFAIL is not referenced. */
/* INFO (output) INTEGER */
/* = 0: successful exit */
/* < 0: if INFO = -i, the i-th argument had an illegal value */
/* > 0: if INFO = i, and i is: */
/* <= N: then i eigenvectors failed to converge. Their */
/* indices are stored in array IFAIL. */
/* > N: if INFO = N + i, for 1 <= i <= N, then CPBSTF */
/* returned INFO = i: B is not positive definite. */
/* The factorization of B could not be completed and */
/* no eigenvalues or eigenvectors were computed. */
/* Further Details */
/* =============== */
/* Based on contributions by */
/* Mark Fahey, Department of Mathematics, Univ. of Kentucky, USA */
/* ===================================================================== */
/* .. Parameters .. */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. External Functions .. */
/* .. */
/* .. External Subroutines .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* .. Executable Statements .. */
/* Test the input parameters. */
/* Parameter adjustments */
ab_dim1 = *ldab;
ab_offset = 1 + ab_dim1;
ab -= ab_offset;
bb_dim1 = *ldbb;
bb_offset = 1 + bb_dim1;
bb -= bb_offset;
q_dim1 = *ldq;
q_offset = 1 + q_dim1;
q -= q_offset;
--w;
z_dim1 = *ldz;
z_offset = 1 + z_dim1;
z__ -= z_offset;
--work;
--rwork;
--iwork;
--ifail;
/* Function Body */
wantz = lsame_(jobz, "V");
upper = lsame_(uplo, "U");
alleig = lsame_(range, "A");
valeig = lsame_(range, "V");
indeig = lsame_(range, "I");
*info = 0;
if (! (wantz || lsame_(jobz, "N"))) {
*info = -1;
} else if (! (alleig || valeig || indeig)) {
*info = -2;
} else if (! (upper || lsame_(uplo, "L"))) {
*info = -3;
} else if (*n < 0) {
*info = -4;
} else if (*ka < 0) {
*info = -5;
} else if (*kb < 0 || *kb > *ka) {
*info = -6;
} else if (*ldab < *ka + 1) {
*info = -8;
} else if (*ldbb < *kb + 1) {
*info = -10;
} else if (*ldq < 1 || wantz && *ldq < *n) {
*info = -12;
} else {
if (valeig) {
if (*n > 0 && *vu <= *vl) {
*info = -14;
}
} else if (indeig) {
if (*il < 1 || *il > max(1,*n)) {
*info = -15;
} else if (*iu < min(*n,*il) || *iu > *n) {
*info = -16;
}
}
}
if (*info == 0) {
if (*ldz < 1 || wantz && *ldz < *n) {
*info = -21;
}
}
if (*info != 0) {
i__1 = -(*info);
xerbla_("CHBGVX", &i__1);
return 0;
}
/* Quick return if possible */
*m = 0;
if (*n == 0) {
return 0;
}
/* Form a split Cholesky factorization of B. */
cpbstf_(uplo, n, kb, &bb[bb_offset], ldbb, info);
if (*info != 0) {
*info = *n + *info;
return 0;
}
/* Transform problem to standard eigenvalue problem. */
chbgst_(jobz, uplo, n, ka, kb, &ab[ab_offset], ldab, &bb[bb_offset], ldbb,
&q[q_offset], ldq, &work[1], &rwork[1], &iinfo);
/* Solve the standard eigenvalue problem. */
/* Reduce Hermitian band matrix to tridiagonal form. */
indd = 1;
inde = indd + *n;
indrwk = inde + *n;
indwrk = 1;
if (wantz) {
*(unsigned char *)vect = 'U';
} else {
*(unsigned char *)vect = 'N';
}
chbtrd_(vect, uplo, n, ka, &ab[ab_offset], ldab, &rwork[indd], &rwork[
inde], &q[q_offset], ldq, &work[indwrk], &iinfo);
/* If all eigenvalues are desired and ABSTOL is less than or equal */
/* to zero, then call SSTERF or CSTEQR. If this fails for some */
/* eigenvalue, then try SSTEBZ. */
test = FALSE_;
if (indeig) {
if (*il == 1 && *iu == *n) {
test = TRUE_;
}
}
if ((alleig || test) && *abstol <= 0.f) {
scopy_(n, &rwork[indd], &c__1, &w[1], &c__1);
indee = indrwk + (*n << 1);
i__1 = *n - 1;
scopy_(&i__1, &rwork[inde], &c__1, &rwork[indee], &c__1);
if (! wantz) {
ssterf_(n, &w[1], &rwork[indee], info);
} else {
clacpy_("A", n, n, &q[q_offset], ldq, &z__[z_offset], ldz);
csteqr_(jobz, n, &w[1], &rwork[indee], &z__[z_offset], ldz, &
rwork[indrwk], info);
if (*info == 0) {
i__1 = *n;
for (i__ = 1; i__ <= i__1; ++i__) {
ifail[i__] = 0;
/* L10: */
}
}
}
if (*info == 0) {
*m = *n;
goto L30;
}
*info = 0;
}
/* Otherwise, call SSTEBZ and, if eigenvectors are desired, */
/* call CSTEIN. */
if (wantz) {
*(unsigned char *)order = 'B';
} else {
*(unsigned char *)order = 'E';
}
indibl = 1;
indisp = indibl + *n;
indiwk = indisp + *n;
sstebz_(range, order, n, vl, vu, il, iu, abstol, &rwork[indd], &rwork[
inde], m, &nsplit, &w[1], &iwork[indibl], &iwork[indisp], &rwork[
indrwk], &iwork[indiwk], info);
if (wantz) {
cstein_(n, &rwork[indd], &rwork[inde], m, &w[1], &iwork[indibl], &
iwork[indisp], &z__[z_offset], ldz, &rwork[indrwk], &iwork[
indiwk], &ifail[1], info);
/* Apply unitary matrix used in reduction to tridiagonal */
/* form to eigenvectors returned by CSTEIN. */
i__1 = *m;
for (j = 1; j <= i__1; ++j) {
ccopy_(n, &z__[j * z_dim1 + 1], &c__1, &work[1], &c__1);
cgemv_("N", n, n, &c_b2, &q[q_offset], ldq, &work[1], &c__1, &
c_b1, &z__[j * z_dim1 + 1], &c__1);
/* L20: */
}
}
L30:
/* If eigenvalues are not in order, then sort them, along with */
/* eigenvectors. */
if (wantz) {
i__1 = *m - 1;
for (j = 1; j <= i__1; ++j) {
i__ = 0;
tmp1 = w[j];
i__2 = *m;
for (jj = j + 1; jj <= i__2; ++jj) {
if (w[jj] < tmp1) {
i__ = jj;
tmp1 = w[jj];
}
/* L40: */
}
if (i__ != 0) {
itmp1 = iwork[indibl + i__ - 1];
w[i__] = w[j];
iwork[indibl + i__ - 1] = iwork[indibl + j - 1];
w[j] = tmp1;
iwork[indibl + j - 1] = itmp1;
cswap_(n, &z__[i__ * z_dim1 + 1], &c__1, &z__[j * z_dim1 + 1],
&c__1);
if (*info != 0) {
itmp1 = ifail[i__];
ifail[i__] = ifail[j];
ifail[j] = itmp1;
}
}
/* L50: */
}
}
return 0;
/* End of CHBGVX */
} /* chbgvx_ */