230 $ WORK, LWORK, RWORK, INFO )
240 INTEGER INFO, ITYPE, LDA, LDB, LWORK, N
243 DOUBLE PRECISION RWORK( * ), W( * )
244 COMPLEX*16 A( LDA, * ), B( LDB, * ), WORK( * )
251 PARAMETER ( ONE = ( 1.0d+0, 0.0d+0 ) )
254 LOGICAL LQUERY, UPPER, WANTZ
256 INTEGER NEIG, LWMIN, LHTRD, LWTRD, KD, IB
261 EXTERNAL lsame, ilaenv2stage
275 wantz = lsame( jobz,
'V' )
276 upper = lsame( uplo,
'U' )
277 lquery = ( lwork.EQ.-1 )
280 IF( itype.LT.1 .OR. itype.GT.3 )
THEN
282 ELSE IF( .NOT.( lsame( jobz,
'N' ) ) )
THEN
284 ELSE IF( .NOT.( upper .OR. lsame( uplo,
'L' ) ) )
THEN
286 ELSE IF( n.LT.0 )
THEN
288 ELSE IF( lda.LT.max( 1, n ) )
THEN
290 ELSE IF( ldb.LT.max( 1, n ) )
THEN
295 kd = ilaenv2stage( 1,
'ZHETRD_2STAGE', jobz, n, -1, -1,
297 ib = ilaenv2stage( 2,
'ZHETRD_2STAGE', jobz, n, kd, -1,
299 lhtrd = ilaenv2stage( 3,
'ZHETRD_2STAGE', jobz, n, kd, ib,
301 lwtrd = ilaenv2stage( 4,
'ZHETRD_2STAGE', jobz, n, kd, ib,
303 lwmin = n + lhtrd + lwtrd
306 IF( lwork.LT.lwmin .AND. .NOT.lquery )
THEN
312 CALL xerbla(
'ZHEGV_2STAGE ', -info )
314 ELSE IF( lquery )
THEN
325 CALL zpotrf( uplo, n, b, ldb, info )
333 CALL zhegst( itype, uplo, n, a, lda, b, ldb, info )
335 $ work, lwork, rwork, info )
344 IF( itype.EQ.1 .OR. itype.EQ.2 )
THEN
355 CALL ztrsm(
'Left', uplo, trans,
'Non-unit', n, neig,
359 ELSE IF( itype.EQ.3 )
THEN
370 CALL ztrmm(
'Left', uplo, trans,
'Non-unit', n, neig,
subroutine zheev_2stage(jobz, uplo, n, a, lda, w, work, lwork, rwork, info)
ZHEEV_2STAGE computes the eigenvalues and, optionally, the left and/or right eigenvectors for HE matr...
subroutine zhegst(itype, uplo, n, a, lda, b, ldb, info)
ZHEGST
subroutine zhegv_2stage(itype, jobz, uplo, n, a, lda, b, ldb, w, work, lwork, rwork, info)
ZHEGV_2STAGE
subroutine ztrmm(side, uplo, transa, diag, m, n, alpha, a, lda, b, ldb)
ZTRMM
subroutine ztrsm(side, uplo, transa, diag, m, n, alpha, a, lda, b, ldb)
ZTRSM