/* Subroutine */ int chegvd_(integer *itype, char *jobz, char *uplo, integer *
n, complex *a, integer *lda, complex *b, integer *ldb, real *w,
complex *work, integer *lwork, real *rwork, integer *lrwork, integer *
iwork, integer *liwork, integer *info)
{
/* System generated locals */
integer a_dim1, a_offset, b_dim1, b_offset, i__1;
real r__1, r__2;
/* Local variables */
integer lopt;
extern logical lsame_(char *, char *);
extern /* Subroutine */ int ctrmm_(char *, char *, char *, char *,
integer *, integer *, complex *, complex *, integer *, complex *,
integer *);
integer lwmin;
char trans[1];
integer liopt;
extern /* Subroutine */ int ctrsm_(char *, char *, char *, char *,
integer *, integer *, complex *, complex *, integer *, complex *,
integer *);
logical upper;
integer lropt;
logical wantz;
extern /* Subroutine */ int cheevd_(char *, char *, integer *, complex *,
integer *, real *, complex *, integer *, real *, integer *,
integer *, integer *, integer *), chegst_(integer
*, char *, integer *, complex *, integer *, complex *, integer *,
integer *), xerbla_(char *, integer *), cpotrf_(
char *, integer *, complex *, integer *, integer *);
integer liwmin, lrwmin;
logical lquery;
/* -- LAPACK driver routine (version 3.2) -- */
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/* November 2006 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* CHEGVD computes all the eigenvalues, and optionally, the eigenvectors */
/* of a complex generalized Hermitian-definite eigenproblem, of the form */
/* A*x=(lambda)*B*x, A*Bx=(lambda)*x, or B*A*x=(lambda)*x. Here A and */
/* B are assumed to be Hermitian 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 */
/* ========= */
/* ITYPE (input) INTEGER */
/* Specifies the problem type to be solved: */
/* = 1: A*x = (lambda)*B*x */
/* = 2: A*B*x = (lambda)*x */
/* = 3: B*A*x = (lambda)*x */
/* 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. */
/* A (input/output) COMPLEX array, dimension (LDA, N) */
/* On entry, the Hermitian matrix A. If UPLO = 'U', the */
/* leading N-by-N upper triangular part of A contains the */
/* upper triangular part of the matrix A. If UPLO = 'L', */
/* the leading N-by-N lower triangular part of A contains */
/* the lower triangular part of the matrix A. */
/* On exit, if JOBZ = 'V', then if INFO = 0, A contains the */
/* matrix Z of eigenvectors. The eigenvectors are normalized */
/* as follows: */
/* if ITYPE = 1 or 2, Z**H*B*Z = I; */
/* if ITYPE = 3, Z**H*inv(B)*Z = I. */
/* If JOBZ = 'N', then on exit the upper triangle (if UPLO='U') */
/* or the lower triangle (if UPLO='L') of A, including the */
/* diagonal, is destroyed. */
/* LDA (input) INTEGER */
/* The leading dimension of the array A. LDA >= max(1,N). */
/* B (input/output) COMPLEX array, dimension (LDB, N) */
/* On entry, the Hermitian matrix B. If UPLO = 'U', the */
/* leading N-by-N upper triangular part of B contains the */
/* upper triangular part of the matrix B. If UPLO = 'L', */
/* the leading N-by-N lower triangular part of B contains */
/* the lower triangular part of the matrix B. */
/* On exit, if INFO <= N, the part of B containing the matrix is */
/* overwritten by the triangular factor U or L from the Cholesky */
/* factorization B = U**H*U or B = L*L**H. */
/* LDB (input) INTEGER */
/* The leading dimension of the array B. LDB >= max(1,N). */
/* W (output) REAL array, dimension (N) */
/* If INFO = 0, the eigenvalues in ascending order. */
/* WORK (workspace/output) COMPLEX array, dimension (MAX(1,LWORK)) */
/* On exit, if INFO = 0, WORK(1) returns the optimal LWORK. */
/* LWORK (input) INTEGER */
/* The length of the array WORK. */
/* If N <= 1, LWORK >= 1. */
/* If JOBZ = 'N' and N > 1, LWORK >= N + 1. */
/* If JOBZ = 'V' and N > 1, LWORK >= 2*N + 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 the 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 the array IWORK. */
/* If N <= 1, LIWORK >= 1. */
/* If JOBZ = 'N' and 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: CPOTRF or CHEEVD returned an error code: */
/* <= N: if INFO = i and JOBZ = 'N', then the algorithm */
/* failed to converge; i off-diagonal elements of an */
/* intermediate tridiagonal form did not converge to */
/* zero; */
/* if INFO = i and JOBZ = 'V', then 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); */
/* > N: if INFO = N + i, for 1 <= i <= N, then the leading */
/* minor of order i of 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 */
/* Modified so that no backsubstitution is performed if CHEEVD fails to */
/* converge (NEIG in old code could be greater than N causing out of */
/* bounds reference to A - reported by Ralf Meyer). Also corrected the */
/* description of INFO and the test on ITYPE. Sven, 16 Feb 05. */
/* ===================================================================== */
/* .. Parameters .. */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. External Functions .. */
/* .. */
/* .. External Subroutines .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* .. Executable Statements .. */
/* Test the input parameters. */
/* Parameter adjustments */
a_dim1 = *lda;
a_offset = 1 + a_dim1;
a -= a_offset;
b_dim1 = *ldb;
b_offset = 1 + b_dim1;
b -= b_offset;
--w;
--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) {
lwmin = (*n << 1) + *n * *n;
lrwmin = *n * 5 + 1 + (*n << 1) * *n;
liwmin = *n * 5 + 3;
} else {
lwmin = *n + 1;
lrwmin = *n;
liwmin = 1;
}
lopt = lwmin;
lropt = lrwmin;
liopt = liwmin;
if (*itype < 1 || *itype > 3) {
*info = -1;
} else if (! (wantz || lsame_(jobz, "N"))) {
*info = -2;
} else if (! (upper || lsame_(uplo, "L"))) {
*info = -3;
} else if (*n < 0) {
*info = -4;
} else if (*lda < max(1,*n)) {
*info = -6;
} else if (*ldb < max(1,*n)) {
*info = -8;
}
if (*info == 0) {
work[1].r = (real) lopt, work[1].i = 0.f;
rwork[1] = (real) lropt;
iwork[1] = liopt;
if (*lwork < lwmin && ! lquery) {
*info = -11;
} else if (*lrwork < lrwmin && ! lquery) {
*info = -13;
} else if (*liwork < liwmin && ! lquery) {
*info = -15;
}
}
if (*info != 0) {
i__1 = -(*info);
xerbla_("CHEGVD", &i__1);
return 0;
} else if (lquery) {
return 0;
}
/* Quick return if possible */
if (*n == 0) {
return 0;
}
/* Form a Cholesky factorization of B. */
cpotrf_(uplo, n, &b[b_offset], ldb, info);
if (*info != 0) {
*info = *n + *info;
return 0;
}
/* Transform problem to standard eigenvalue problem and solve. */
chegst_(itype, uplo, n, &a[a_offset], lda, &b[b_offset], ldb, info);
cheevd_(jobz, uplo, n, &a[a_offset], lda, &w[1], &work[1], lwork, &rwork[
1], lrwork, &iwork[1], liwork, info);
/* Computing MAX */
r__1 = (real) lopt, r__2 = work[1].r;
lopt = dmax(r__1,r__2);
/* Computing MAX */
r__1 = (real) lropt;
lropt = dmax(r__1,rwork[1]);
/* Computing MAX */
r__1 = (real) liopt, r__2 = (real) iwork[1];
liopt = dmax(r__1,r__2);
if (wantz && *info == 0) {
/* Backtransform eigenvectors to the original problem. */
if (*itype == 1 || *itype == 2) {
/* For A*x=(lambda)*B*x and A*B*x=(lambda)*x; */
/* backtransform eigenvectors: x = inv(L)'*y or inv(U)*y */
if (upper) {
*(unsigned char *)trans = 'N';
} else {
*(unsigned char *)trans = 'C';
}
ctrsm_("Left", uplo, trans, "Non-unit", n, n, &c_b1, &b[b_offset],
ldb, &a[a_offset], lda);
} else if (*itype == 3) {
/* For B*A*x=(lambda)*x; */
/* backtransform eigenvectors: x = L*y or U'*y */
if (upper) {
*(unsigned char *)trans = 'C';
} else {
*(unsigned char *)trans = 'N';
}
ctrmm_("Left", uplo, trans, "Non-unit", n, n, &c_b1, &b[b_offset],
ldb, &a[a_offset], lda);
}
}
work[1].r = (real) lopt, work[1].i = 0.f;
rwork[1] = (real) lropt;
iwork[1] = liopt;
return 0;
/* End of CHEGVD */
} /* chegvd_ */
/* Subroutine */ int chegvd_(integer *itype, char *jobz, char *uplo, integer *
n, complex *a, integer *lda, complex *b, integer *ldb, real *w,
complex *work, integer *lwork, real *rwork, integer *lrwork, integer *
iwork, integer *liwork, integer *info)
{
/* -- LAPACK driver routine (version 3.0) --
Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
Courant Institute, Argonne National Lab, and Rice University
June 30, 1999
Purpose
=======
CHEGVD computes all the eigenvalues, and optionally, the eigenvectors
of a complex generalized Hermitian-definite eigenproblem, of the form
A*x=(lambda)*B*x, A*Bx=(lambda)*x, or B*A*x=(lambda)*x. Here A and
B are assumed to be Hermitian 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
=========
ITYPE (input) INTEGER
Specifies the problem type to be solved:
= 1: A*x = (lambda)*B*x
= 2: A*B*x = (lambda)*x
= 3: B*A*x = (lambda)*x
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.
A (input/output) COMPLEX array, dimension (LDA, N)
On entry, the Hermitian matrix A. If UPLO = 'U', the
leading N-by-N upper triangular part of A contains the
upper triangular part of the matrix A. If UPLO = 'L',
the leading N-by-N lower triangular part of A contains
the lower triangular part of the matrix A.
On exit, if JOBZ = 'V', then if INFO = 0, A contains the
matrix Z of eigenvectors. The eigenvectors are normalized
as follows:
if ITYPE = 1 or 2, Z**H*B*Z = I;
if ITYPE = 3, Z**H*inv(B)*Z = I.
If JOBZ = 'N', then on exit the upper triangle (if UPLO='U')
or the lower triangle (if UPLO='L') of A, including the
diagonal, is destroyed.
LDA (input) INTEGER
The leading dimension of the array A. LDA >= max(1,N).
B (input/output) COMPLEX array, dimension (LDB, N)
On entry, the Hermitian matrix B. If UPLO = 'U', the
leading N-by-N upper triangular part of B contains the
upper triangular part of the matrix B. If UPLO = 'L',
the leading N-by-N lower triangular part of B contains
the lower triangular part of the matrix B.
On exit, if INFO <= N, the part of B containing the matrix is
overwritten by the triangular factor U or L from the Cholesky
factorization B = U**H*U or B = L*L**H.
LDB (input) INTEGER
The leading dimension of the array B. LDB >= max(1,N).
W (output) REAL array, dimension (N)
If INFO = 0, the eigenvalues in ascending order.
WORK (workspace/output) COMPLEX array, dimension (LWORK)
On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
LWORK (input) INTEGER
The length of the array WORK.
If N <= 1, LWORK >= 1.
If JOBZ = 'N' and N > 1, LWORK >= N + 1.
If JOBZ = 'V' and N > 1, LWORK >= 2*N + N**2.
If LWORK = -1, then a workspace query is assumed; the routine
only calculates the optimal size of the WORK array, returns
this value as the first entry of the WORK array, and no error
message related to LWORK is issued by XERBLA.
RWORK (workspace/output) REAL array, dimension (LRWORK)
On exit, if INFO = 0, RWORK(1) returns the optimal LRWORK.
LRWORK (input) INTEGER
The dimension of the 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 size of the RWORK array,
returns this value as the first entry of the RWORK array, and
no error message related to LRWORK is issued by XERBLA.
IWORK (workspace/output) INTEGER array, dimension (LIWORK)
On exit, if INFO = 0, IWORK(1) returns the optimal LIWORK.
LIWORK (input) INTEGER
The dimension of the array IWORK.
If N <= 1, LIWORK >= 1.
If JOBZ = 'N' and N > 1, LIWORK >= 1.
If JOBZ = 'V' and N > 1, LIWORK >= 3 + 5*N.
INFO (output) INTEGER
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value
> 0: CPOTRF or CHEEVD returned an error code:
<= N: if INFO = i, CHEEVD 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 the leading
minor of order i of 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 */
/* Table of constant values */
static complex c_b1 = {1.f,0.f};
/* System generated locals */
integer a_dim1, a_offset, b_dim1, b_offset, i__1;
real r__1, r__2;
/* Local variables */
static integer neig, lopt;
extern logical lsame_(char *, char *);
extern /* Subroutine */ int ctrmm_(char *, char *, char *, char *,
integer *, integer *, complex *, complex *, integer *, complex *,
integer *);
static integer lwmin;
static char trans[1];
static integer liopt;
extern /* Subroutine */ int ctrsm_(char *, char *, char *, char *,
integer *, integer *, complex *, complex *, integer *, complex *,
integer *);
static logical upper;
static integer lropt;
static logical wantz;
extern /* Subroutine */ int cheevd_(char *, char *, integer *, complex *,
integer *, real *, complex *, integer *, real *, integer *,
integer *, integer *, integer *), chegst_(integer
*, char *, integer *, complex *, integer *, complex *, integer *,
integer *), xerbla_(char *, integer *), cpotrf_(
char *, integer *, complex *, integer *, integer *);
static integer liwmin, lrwmin;
static logical lquery;
a_dim1 = *lda;
a_offset = 1 + a_dim1 * 1;
a -= a_offset;
b_dim1 = *ldb;
b_offset = 1 + b_dim1 * 1;
b -= b_offset;
--w;
--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;
lopt = lwmin;
lropt = lrwmin;
liopt = liwmin;
} else {
if (wantz) {
lwmin = (*n << 1) + *n * *n;
lrwmin = *n * 5 + 1 + (*n << 1) * *n;
liwmin = *n * 5 + 3;
} else {
lwmin = *n + 1;
lrwmin = *n;
liwmin = 1;
}
lopt = lwmin;
lropt = lrwmin;
liopt = liwmin;
}
if (*itype < 0 || *itype > 3) {
*info = -1;
} else if (! (wantz || lsame_(jobz, "N"))) {
*info = -2;
} else if (! (upper || lsame_(uplo, "L"))) {
*info = -3;
} else if (*n < 0) {
*info = -4;
} else if (*lda < max(1,*n)) {
*info = -6;
} else if (*ldb < max(1,*n)) {
*info = -8;
} else if (*lwork < lwmin && ! lquery) {
*info = -11;
} else if (*lrwork < lrwmin && ! lquery) {
*info = -13;
} else if (*liwork < liwmin && ! lquery) {
*info = -15;
}
if (*info == 0) {
work[1].r = (real) lopt, work[1].i = 0.f;
rwork[1] = (real) lropt;
iwork[1] = liopt;
}
if (*info != 0) {
i__1 = -(*info);
xerbla_("CHEGVD", &i__1);
return 0;
} else if (lquery) {
return 0;
}
/* Quick return if possible */
if (*n == 0) {
return 0;
}
/* Form a Cholesky factorization of B. */
cpotrf_(uplo, n, &b[b_offset], ldb, info);
if (*info != 0) {
*info = *n + *info;
return 0;
}
/* Transform problem to standard eigenvalue problem and solve. */
chegst_(itype, uplo, n, &a[a_offset], lda, &b[b_offset], ldb, info);
cheevd_(jobz, uplo, n, &a[a_offset], lda, &w[1], &work[1], lwork, &rwork[
1], lrwork, &iwork[1], liwork, info);
/* Computing MAX */
r__1 = (real) lopt, r__2 = work[1].r;
lopt = dmax(r__1,r__2);
/* Computing MAX */
r__1 = (real) lropt;
lropt = dmax(r__1,rwork[1]);
/* Computing MAX */
r__1 = (real) liopt, r__2 = (real) iwork[1];
liopt = dmax(r__1,r__2);
if (wantz) {
/* Backtransform eigenvectors to the original problem. */
neig = *n;
if (*info > 0) {
neig = *info - 1;
}
if (*itype == 1 || *itype == 2) {
/* For A*x=(lambda)*B*x and A*B*x=(lambda)*x;
backtransform eigenvectors: x = inv(L)'*y or inv(U)*y */
if (upper) {
*(unsigned char *)trans = 'N';
} else {
*(unsigned char *)trans = 'C';
}
ctrsm_("Left", uplo, trans, "Non-unit", n, &neig, &c_b1, &b[
b_offset], ldb, &a[a_offset], lda);
} else if (*itype == 3) {
/* For B*A*x=(lambda)*x;
backtransform eigenvectors: x = L*y or U'*y */
if (upper) {
*(unsigned char *)trans = 'C';
} else {
*(unsigned char *)trans = 'N';
}
ctrmm_("Left", uplo, trans, "Non-unit", n, &neig, &c_b1, &b[
b_offset], ldb, &a[a_offset], lda);
}
}
work[1].r = (real) lopt, work[1].i = 0.f;
rwork[1] = (real) lropt;
iwork[1] = liopt;
return 0;
/* End of CHEGVD */
} /* chegvd_ */
int main(void)
{
/* Local scalars */
lapack_int itype, itype_i;
char uplo, uplo_i;
lapack_int n, n_i;
lapack_int lda, lda_i;
lapack_int lda_r;
lapack_int ldb, ldb_i;
lapack_int ldb_r;
lapack_int info, info_i;
lapack_int i;
int failed;
/* Local arrays */
lapack_complex_float *a = NULL, *a_i = NULL;
lapack_complex_float *b = NULL, *b_i = NULL;
lapack_complex_float *a_save = NULL;
lapack_complex_float *a_r = NULL;
lapack_complex_float *b_r = NULL;
/* Iniitialize the scalar parameters */
init_scalars_chegst( &itype, &uplo, &n, &lda, &ldb );
lda_r = n+2;
ldb_r = n+2;
itype_i = itype;
uplo_i = uplo;
n_i = n;
lda_i = lda;
ldb_i = ldb;
/* Allocate memory for the LAPACK routine arrays */
a = (lapack_complex_float *)
LAPACKE_malloc( lda*n * sizeof(lapack_complex_float) );
b = (lapack_complex_float *)
LAPACKE_malloc( ldb*n * sizeof(lapack_complex_float) );
/* Allocate memory for the C interface function arrays */
a_i = (lapack_complex_float *)
LAPACKE_malloc( lda*n * sizeof(lapack_complex_float) );
b_i = (lapack_complex_float *)
LAPACKE_malloc( ldb*n * sizeof(lapack_complex_float) );
/* Allocate memory for the backup arrays */
a_save = (lapack_complex_float *)
LAPACKE_malloc( lda*n * sizeof(lapack_complex_float) );
/* Allocate memory for the row-major arrays */
a_r = (lapack_complex_float *)
LAPACKE_malloc( n*(n+2) * sizeof(lapack_complex_float) );
b_r = (lapack_complex_float *)
LAPACKE_malloc( n*(n+2) * sizeof(lapack_complex_float) );
/* Initialize input arrays */
init_a( lda*n, a );
init_b( ldb*n, b );
/* Backup the ouptut arrays */
for( i = 0; i < lda*n; i++ ) {
a_save[i] = a[i];
}
/* Call the LAPACK routine */
chegst_( &itype, &uplo, &n, a, &lda, b, &ldb, &info );
/* Initialize input data, call the column-major middle-level
* interface to LAPACK routine and check the results */
for( i = 0; i < lda*n; i++ ) {
a_i[i] = a_save[i];
}
for( i = 0; i < ldb*n; i++ ) {
b_i[i] = b[i];
}
info_i = LAPACKE_chegst_work( LAPACK_COL_MAJOR, itype_i, uplo_i, n_i, a_i,
lda_i, b_i, ldb_i );
failed = compare_chegst( a, a_i, info, info_i, lda, n );
if( failed == 0 ) {
printf( "PASSED: column-major middle-level interface to chegst\n" );
} else {
printf( "FAILED: column-major middle-level interface to chegst\n" );
}
/* Initialize input data, call the column-major high-level
* interface to LAPACK routine and check the results */
for( i = 0; i < lda*n; i++ ) {
a_i[i] = a_save[i];
}
for( i = 0; i < ldb*n; i++ ) {
b_i[i] = b[i];
}
info_i = LAPACKE_chegst( LAPACK_COL_MAJOR, itype_i, uplo_i, n_i, a_i, lda_i,
b_i, ldb_i );
failed = compare_chegst( a, a_i, info, info_i, lda, n );
if( failed == 0 ) {
printf( "PASSED: column-major high-level interface to chegst\n" );
} else {
printf( "FAILED: column-major high-level interface to chegst\n" );
}
/* Initialize input data, call the row-major middle-level
* interface to LAPACK routine and check the results */
for( i = 0; i < lda*n; i++ ) {
a_i[i] = a_save[i];
}
for( i = 0; i < ldb*n; i++ ) {
b_i[i] = b[i];
}
LAPACKE_cge_trans( LAPACK_COL_MAJOR, n, n, a_i, lda, a_r, n+2 );
LAPACKE_cge_trans( LAPACK_COL_MAJOR, n, n, b_i, ldb, b_r, n+2 );
info_i = LAPACKE_chegst_work( LAPACK_ROW_MAJOR, itype_i, uplo_i, n_i, a_r,
lda_r, b_r, ldb_r );
LAPACKE_cge_trans( LAPACK_ROW_MAJOR, n, n, a_r, n+2, a_i, lda );
failed = compare_chegst( a, a_i, info, info_i, lda, n );
if( failed == 0 ) {
printf( "PASSED: row-major middle-level interface to chegst\n" );
} else {
printf( "FAILED: row-major middle-level interface to chegst\n" );
}
/* Initialize input data, call the row-major high-level
* interface to LAPACK routine and check the results */
for( i = 0; i < lda*n; i++ ) {
a_i[i] = a_save[i];
}
for( i = 0; i < ldb*n; i++ ) {
b_i[i] = b[i];
}
/* Init row_major arrays */
LAPACKE_cge_trans( LAPACK_COL_MAJOR, n, n, a_i, lda, a_r, n+2 );
LAPACKE_cge_trans( LAPACK_COL_MAJOR, n, n, b_i, ldb, b_r, n+2 );
info_i = LAPACKE_chegst( LAPACK_ROW_MAJOR, itype_i, uplo_i, n_i, a_r, lda_r,
b_r, ldb_r );
LAPACKE_cge_trans( LAPACK_ROW_MAJOR, n, n, a_r, n+2, a_i, lda );
failed = compare_chegst( a, a_i, info, info_i, lda, n );
if( failed == 0 ) {
printf( "PASSED: row-major high-level interface to chegst\n" );
} else {
printf( "FAILED: row-major high-level interface to chegst\n" );
}
/* Release memory */
if( a != NULL ) {
LAPACKE_free( a );
}
if( a_i != NULL ) {
LAPACKE_free( a_i );
}
if( a_r != NULL ) {
LAPACKE_free( a_r );
}
if( a_save != NULL ) {
LAPACKE_free( a_save );
}
if( b != NULL ) {
LAPACKE_free( b );
}
if( b_i != NULL ) {
LAPACKE_free( b_i );
}
if( b_r != NULL ) {
LAPACKE_free( b_r );
}
return 0;
}
/* Subroutine */ int chegv_(integer *itype, char *jobz, char *uplo, integer *
n, complex *a, integer *lda, complex *b, integer *ldb, real *w,
complex *work, integer *lwork, real *rwork, integer *info)
{
/* -- LAPACK driver routine (version 3.0) --
Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
Courant Institute, Argonne National Lab, and Rice University
June 30, 1999
Purpose
=======
CHEGV computes all the eigenvalues, and optionally, the eigenvectors
of a complex generalized Hermitian-definite eigenproblem, of the form
A*x=(lambda)*B*x, A*Bx=(lambda)*x, or B*A*x=(lambda)*x.
Here A and B are assumed to be Hermitian and B is also
positive definite.
Arguments
=========
ITYPE (input) INTEGER
Specifies the problem type to be solved:
= 1: A*x = (lambda)*B*x
= 2: A*B*x = (lambda)*x
= 3: B*A*x = (lambda)*x
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.
A (input/output) COMPLEX array, dimension (LDA, N)
On entry, the Hermitian matrix A. If UPLO = 'U', the
leading N-by-N upper triangular part of A contains the
upper triangular part of the matrix A. If UPLO = 'L',
the leading N-by-N lower triangular part of A contains
the lower triangular part of the matrix A.
On exit, if JOBZ = 'V', then if INFO = 0, A contains the
matrix Z of eigenvectors. The eigenvectors are normalized
as follows:
if ITYPE = 1 or 2, Z**H*B*Z = I;
if ITYPE = 3, Z**H*inv(B)*Z = I.
If JOBZ = 'N', then on exit the upper triangle (if UPLO='U')
or the lower triangle (if UPLO='L') of A, including the
diagonal, is destroyed.
LDA (input) INTEGER
The leading dimension of the array A. LDA >= max(1,N).
B (input/output) COMPLEX array, dimension (LDB, N)
On entry, the Hermitian positive definite matrix B.
If UPLO = 'U', the leading N-by-N upper triangular part of B
contains the upper triangular part of the matrix B.
If UPLO = 'L', the leading N-by-N lower triangular part of B
contains the lower triangular part of the matrix B.
On exit, if INFO <= N, the part of B containing the matrix is
overwritten by the triangular factor U or L from the Cholesky
factorization B = U**H*U or B = L*L**H.
LDB (input) INTEGER
The leading dimension of the array B. LDB >= max(1,N).
W (output) REAL array, dimension (N)
If INFO = 0, the eigenvalues in ascending order.
WORK (workspace/output) COMPLEX array, dimension (LWORK)
On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
LWORK (input) INTEGER
The length of the array WORK. LWORK >= max(1,2*N-1).
For optimal efficiency, LWORK >= (NB+1)*N,
where NB is the blocksize for CHETRD returned by ILAENV.
If LWORK = -1, then a workspace query is assumed; the routine
only calculates the optimal size of the WORK array, returns
this value as the first entry of the WORK array, and no error
message related to LWORK is issued by XERBLA.
RWORK (workspace) REAL array, dimension (max(1, 3*N-2))
INFO (output) INTEGER
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value
> 0: CPOTRF or CHEEV returned an error code:
<= N: if INFO = i, CHEEV 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 the leading
minor of order i of 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 */
/* Table of constant values */
static complex c_b1 = {1.f,0.f};
static integer c__1 = 1;
static integer c_n1 = -1;
/* System generated locals */
integer a_dim1, a_offset, b_dim1, b_offset, i__1, i__2;
/* Local variables */
static integer neig;
extern /* Subroutine */ int cheev_(char *, char *, integer *, complex *,
integer *, real *, complex *, integer *, real *, integer *);
extern logical lsame_(char *, char *);
extern /* Subroutine */ int ctrmm_(char *, char *, char *, char *,
integer *, integer *, complex *, complex *, integer *, complex *,
integer *);
static char trans[1];
extern /* Subroutine */ int ctrsm_(char *, char *, char *, char *,
integer *, integer *, complex *, complex *, integer *, complex *,
integer *);
static logical upper, wantz;
static integer nb;
extern /* Subroutine */ int chegst_(integer *, char *, integer *, complex
*, integer *, complex *, integer *, integer *);
extern integer ilaenv_(integer *, char *, char *, integer *, integer *,
integer *, integer *, ftnlen, ftnlen);
extern /* Subroutine */ int xerbla_(char *, integer *), cpotrf_(
char *, integer *, complex *, integer *, integer *);
static integer lwkopt;
static logical lquery;
a_dim1 = *lda;
a_offset = 1 + a_dim1 * 1;
a -= a_offset;
b_dim1 = *ldb;
b_offset = 1 + b_dim1 * 1;
b -= b_offset;
--w;
--work;
--rwork;
/* Function Body */
wantz = lsame_(jobz, "V");
upper = lsame_(uplo, "U");
lquery = *lwork == -1;
*info = 0;
if (*itype < 1 || *itype > 3) {
*info = -1;
} else if (! (wantz || lsame_(jobz, "N"))) {
*info = -2;
} else if (! (upper || lsame_(uplo, "L"))) {
*info = -3;
} else if (*n < 0) {
*info = -4;
} else if (*lda < max(1,*n)) {
*info = -6;
} else if (*ldb < max(1,*n)) {
*info = -8;
} else /* if(complicated condition) */ {
/* Computing MAX */
i__1 = 1, i__2 = (*n << 1) - 1;
if (*lwork < max(i__1,i__2) && ! lquery) {
*info = -11;
}
}
if (*info == 0) {
nb = ilaenv_(&c__1, "CHETRD", uplo, n, &c_n1, &c_n1, &c_n1, (ftnlen)6,
(ftnlen)1);
lwkopt = (nb + 1) * *n;
work[1].r = (real) lwkopt, work[1].i = 0.f;
}
if (*info != 0) {
i__1 = -(*info);
xerbla_("CHEGV ", &i__1);
return 0;
}
/* Quick return if possible */
if (*n == 0) {
return 0;
}
/* Form a Cholesky factorization of B. */
cpotrf_(uplo, n, &b[b_offset], ldb, info);
if (*info != 0) {
*info = *n + *info;
return 0;
}
/* Transform problem to standard eigenvalue problem and solve. */
chegst_(itype, uplo, n, &a[a_offset], lda, &b[b_offset], ldb, info);
cheev_(jobz, uplo, n, &a[a_offset], lda, &w[1], &work[1], lwork, &rwork[1]
, info);
if (wantz) {
/* Backtransform eigenvectors to the original problem. */
neig = *n;
if (*info > 0) {
neig = *info - 1;
}
if (*itype == 1 || *itype == 2) {
/* For A*x=(lambda)*B*x and A*B*x=(lambda)*x;
backtransform eigenvectors: x = inv(L)'*y or inv(U)*y */
if (upper) {
*(unsigned char *)trans = 'N';
} else {
*(unsigned char *)trans = 'C';
}
ctrsm_("Left", uplo, trans, "Non-unit", n, &neig, &c_b1, &b[
b_offset], ldb, &a[a_offset], lda);
} else if (*itype == 3) {
/* For B*A*x=(lambda)*x;
backtransform eigenvectors: x = L*y or U'*y */
if (upper) {
*(unsigned char *)trans = 'C';
} else {
*(unsigned char *)trans = 'N';
}
ctrmm_("Left", uplo, trans, "Non-unit", n, &neig, &c_b1, &b[
b_offset], ldb, &a[a_offset], lda);
}
}
work[1].r = (real) lwkopt, work[1].i = 0.f;
return 0;
/* End of CHEGV */
} /* chegv_ */
/* Subroutine */ int chegvx_(integer *itype, char *jobz, char *range, char *
uplo, integer *n, complex *a, integer *lda, complex *b, integer *ldb,
real *vl, real *vu, integer *il, integer *iu, real *abstol, integer *
m, real *w, complex *z__, integer *ldz, complex *work, integer *lwork,
real *rwork, integer *iwork, integer *ifail, integer *info)
{
/* -- LAPACK driver routine (version 3.0) --
Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
Courant Institute, Argonne National Lab, and Rice University
June 30, 1999
Purpose
=======
CHEGVX computes selected eigenvalues, and optionally, eigenvectors
of a complex generalized Hermitian-definite eigenproblem, of the form
A*x=(lambda)*B*x, A*Bx=(lambda)*x, or B*A*x=(lambda)*x. Here A and
B are assumed to be Hermitian and B is also positive definite.
Eigenvalues and eigenvectors can be selected by specifying either a
range of values or a range of indices for the desired eigenvalues.
Arguments
=========
ITYPE (input) INTEGER
Specifies the problem type to be solved:
= 1: A*x = (lambda)*B*x
= 2: A*B*x = (lambda)*x
= 3: B*A*x = (lambda)*x
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.
A (input/output) COMPLEX array, dimension (LDA, N)
On entry, the Hermitian matrix A. If UPLO = 'U', the
leading N-by-N upper triangular part of A contains the
upper triangular part of the matrix A. If UPLO = 'L',
the leading N-by-N lower triangular part of A contains
the lower triangular part of the matrix A.
On exit, the lower triangle (if UPLO='L') or the upper
triangle (if UPLO='U') of A, including the diagonal, is
destroyed.
LDA (input) INTEGER
The leading dimension of the array A. LDA >= max(1,N).
B (input/output) COMPLEX array, dimension (LDB, N)
On entry, the Hermitian matrix B. If UPLO = 'U', the
leading N-by-N upper triangular part of B contains the
upper triangular part of the matrix B. If UPLO = 'L',
the leading N-by-N lower triangular part of B contains
the lower triangular part of the matrix B.
On exit, if INFO <= N, the part of B containing the matrix is
overwritten by the triangular factor U or L from the Cholesky
factorization B = U**H*U or B = L*L**H.
LDB (input) INTEGER
The leading dimension of the array B. LDB >= 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 A 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)
The first M elements contain the selected
eigenvalues in ascending order.
Z (output) COMPLEX array, dimension (LDZ, max(1,M))
If JOBZ = 'N', then Z is not referenced.
If JOBZ = 'V', then if INFO = 0, the first M columns of Z
contain the orthonormal eigenvectors of the matrix A
corresponding to the selected eigenvalues, with the i-th
column of Z holding the eigenvector associated with W(i).
The eigenvectors are normalized as follows:
if ITYPE = 1 or 2, Z**T*B*Z = I;
if ITYPE = 3, Z**T*inv(B)*Z = I.
If an eigenvector fails to converge, then that column of Z
contains the latest approximation to the eigenvector, and the
index of the eigenvector is returned in IFAIL.
Note: the user must ensure that at least max(1,M) columns are
supplied in the array Z; if RANGE = 'V', the exact value of M
is not known in advance and an upper bound must be used.
LDZ (input) INTEGER
The leading dimension of the array Z. LDZ >= 1, and if
JOBZ = 'V', LDZ >= max(1,N).
WORK (workspace/output) COMPLEX array, dimension (LWORK)
On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
LWORK (input) INTEGER
The length of the array WORK. LWORK >= max(1,2*N-1).
For optimal efficiency, LWORK >= (NB+1)*N,
where NB is the blocksize for CHETRD returned by ILAENV.
If LWORK = -1, then a workspace query is assumed; the routine
only calculates the optimal size of the WORK array, returns
this value as the first entry of the WORK array, and no error
message related to LWORK is issued by XERBLA.
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: CPOTRF or CHEEVX returned an error code:
<= N: if INFO = i, CHEEVX failed to converge;
i eigenvectors failed to converge. Their indices
are stored in array IFAIL.
> N: if INFO = N + i, for 1 <= i <= N, then the leading
minor of order i of 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 */
/* Table of constant values */
static complex c_b1 = {1.f,0.f};
static integer c__1 = 1;
static integer c_n1 = -1;
/* System generated locals */
integer a_dim1, a_offset, b_dim1, b_offset, z_dim1, z_offset, i__1, i__2;
/* Local variables */
static integer lopt;
extern logical lsame_(char *, char *);
extern /* Subroutine */ int ctrmm_(char *, char *, char *, char *,
integer *, integer *, complex *, complex *, integer *, complex *,
integer *);
static char trans[1];
extern /* Subroutine */ int ctrsm_(char *, char *, char *, char *,
integer *, integer *, complex *, complex *, integer *, complex *,
integer *);
static logical upper, wantz;
static integer nb;
static logical alleig, indeig, valeig;
extern /* Subroutine */ int chegst_(integer *, char *, integer *, complex
*, integer *, complex *, integer *, integer *);
extern integer ilaenv_(integer *, char *, char *, integer *, integer *,
integer *, integer *, ftnlen, ftnlen);
extern /* Subroutine */ int xerbla_(char *, integer *), cheevx_(
char *, char *, char *, integer *, complex *, integer *, real *,
real *, integer *, integer *, real *, integer *, real *, complex *
, integer *, complex *, integer *, real *, integer *, integer *,
integer *), cpotrf_(char *, integer *,
complex *, integer *, integer *);
static integer lwkopt;
static logical lquery;
a_dim1 = *lda;
a_offset = 1 + a_dim1 * 1;
a -= a_offset;
b_dim1 = *ldb;
b_offset = 1 + b_dim1 * 1;
b -= b_offset;
--w;
z_dim1 = *ldz;
z_offset = 1 + z_dim1 * 1;
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");
lquery = *lwork == -1;
*info = 0;
if (*itype < 0 || *itype > 3) {
*info = -1;
} else if (! (wantz || lsame_(jobz, "N"))) {
*info = -2;
} else if (! (alleig || valeig || indeig)) {
*info = -3;
} else if (! (upper || lsame_(uplo, "L"))) {
*info = -4;
} else if (*n < 0) {
*info = -5;
} else if (*lda < max(1,*n)) {
*info = -7;
} else if (*ldb < max(1,*n)) {
*info = -9;
} else if (valeig && *n > 0) {
if (*vu <= *vl) {
*info = -11;
}
} else if (indeig && *il < 1) {
*info = -12;
} else if (indeig && (*iu < min(*n,*il) || *iu > *n)) {
*info = -13;
} else if (*ldz < 1 || wantz && *ldz < *n) {
*info = -18;
} else /* if(complicated condition) */ {
/* Computing MAX */
i__1 = 1, i__2 = (*n << 1) - 1;
if (*lwork < max(i__1,i__2) && ! lquery) {
*info = -20;
}
}
if (*info == 0) {
nb = ilaenv_(&c__1, "CHETRD", uplo, n, &c_n1, &c_n1, &c_n1, (ftnlen)6,
(ftnlen)1);
lwkopt = (nb + 1) * *n;
work[1].r = (real) lwkopt, work[1].i = 0.f;
}
if (*info != 0) {
i__1 = -(*info);
xerbla_("CHEGVX", &i__1);
return 0;
} else if (lquery) {
return 0;
}
/* Quick return if possible */
*m = 0;
if (*n == 0) {
work[1].r = 1.f, work[1].i = 0.f;
return 0;
}
/* Form a Cholesky factorization of B. */
cpotrf_(uplo, n, &b[b_offset], ldb, info);
if (*info != 0) {
*info = *n + *info;
return 0;
}
/* Transform problem to standard eigenvalue problem and solve. */
chegst_(itype, uplo, n, &a[a_offset], lda, &b[b_offset], ldb, info);
cheevx_(jobz, range, uplo, n, &a[a_offset], lda, vl, vu, il, iu, abstol,
m, &w[1], &z__[z_offset], ldz, &work[1], lwork, &rwork[1], &iwork[
1], &ifail[1], info);
lopt = work[1].r;
if (wantz) {
/* Backtransform eigenvectors to the original problem. */
if (*info > 0) {
*m = *info - 1;
}
if (*itype == 1 || *itype == 2) {
/* For A*x=(lambda)*B*x and A*B*x=(lambda)*x;
backtransform eigenvectors: x = inv(L)'*y or inv(U)*y */
if (upper) {
*(unsigned char *)trans = 'N';
} else {
*(unsigned char *)trans = 'C';
}
ctrsm_("Left", uplo, trans, "Non-unit", n, m, &c_b1, &b[b_offset],
ldb, &z__[z_offset], ldz);
} else if (*itype == 3) {
/* For B*A*x=(lambda)*x;
backtransform eigenvectors: x = L*y or U'*y */
if (upper) {
*(unsigned char *)trans = 'C';
} else {
*(unsigned char *)trans = 'N';
}
ctrmm_("Left", uplo, trans, "Non-unit", n, m, &c_b1, &b[b_offset],
ldb, &z__[z_offset], ldz);
}
}
/* Set WORK(1) to optimal complex workspace size. */
work[1].r = (real) lwkopt, work[1].i = 0.f;
return 0;
/* End of CHEGVX */
} /* chegvx_ */
