SRC/zlaqz2.f(3) | Library Functions Manual | SRC/zlaqz2.f(3) |
NAME
SRC/zlaqz2.f
SYNOPSIS
Functions/Subroutines
recursive subroutine zlaqz2 (ilschur, ilq, ilz, n, ilo,
ihi, nw, a, lda, b, ldb, q, ldq, z, ldz, ns, nd, alpha, beta, qc, ldqc, zc,
ldzc, work, lwork, rwork, rec, info)
ZLAQZ2
Function/Subroutine Documentation
recursive subroutine zlaqz2 (logical, intent(in) ilschur, logical, intent(in) ilq, logical, intent(in) ilz, integer, intent(in) n, integer, intent(in) ilo, integer, intent(in) ihi, integer, intent(in) nw, complex*16, dimension( lda, * ), intent(inout) a, integer, intent(in) lda, complex*16, dimension( ldb, * ), intent(inout) b, integer, intent(in) ldb, complex*16, dimension( ldq, * ), intent(inout) q, integer, intent(in) ldq, complex*16, dimension( ldz, * ), intent(inout) z, integer, intent(in) ldz, integer, intent(out) ns, integer, intent(out) nd, complex*16, dimension( * ), intent(inout) alpha, complex*16, dimension( * ), intent(inout) beta, complex*16, dimension( ldqc, * ) qc, integer, intent(in) ldqc, complex*16, dimension( ldzc, * ) zc, integer, intent(in) ldzc, complex*16, dimension( * ) work, integer, intent(in) lwork, double precision, dimension( * ) rwork, integer, intent(in) rec, integer, intent(out) info)
ZLAQZ2
Purpose:
ZLAQZ2 performs AED
Parameters
ILSCHUR
ILSCHUR is LOGICAL Determines whether or not to update the full Schur form
ILQ
ILQ is LOGICAL Determines whether or not to update the matrix Q
ILZ
ILZ is LOGICAL Determines whether or not to update the matrix Z
N
N is INTEGER The order of the matrices A, B, Q, and Z. N >= 0.
ILO
ILO is INTEGER
IHI
IHI is INTEGER ILO and IHI mark the rows and columns of (A,B) which are to be normalized
NW
NW is INTEGER The desired size of the deflation window.
A
A is COMPLEX*16 array, dimension (LDA, N)
LDA
LDA is INTEGER The leading dimension of the array A. LDA >= max( 1, N ).
B
B is COMPLEX*16 array, dimension (LDB, N)
LDB
LDB is INTEGER The leading dimension of the array B. LDB >= max( 1, N ).
Q
Q is COMPLEX*16 array, dimension (LDQ, N)
LDQ
LDQ is INTEGER
Z
Z is COMPLEX*16 array, dimension (LDZ, N)
LDZ
LDZ is INTEGER
NS
NS is INTEGER The number of unconverged eigenvalues available to use as shifts.
ND
ND is INTEGER The number of converged eigenvalues found.
ALPHA
ALPHA is COMPLEX*16 array, dimension (N) Each scalar alpha defining an eigenvalue of GNEP.
BETA
BETA is COMPLEX*16 array, dimension (N) The scalars beta that define the eigenvalues of GNEP. Together, the quantities alpha = ALPHA(j) and beta = BETA(j) represent the j-th eigenvalue of the matrix pair (A,B), in one of the forms lambda = alpha/beta or mu = beta/alpha. Since either lambda or mu may overflow, they should not, in general, be computed.
QC
QC is COMPLEX*16 array, dimension (LDQC, NW)
LDQC
LDQC is INTEGER
ZC
ZC is COMPLEX*16 array, dimension (LDZC, NW)
LDZC
LDZ is INTEGER
WORK
WORK is COMPLEX*16 array, dimension (MAX(1,LWORK)) On exit, if INFO >= 0, WORK(1) returns the optimal LWORK.
LWORK
LWORK is INTEGER The dimension of the array WORK. LWORK >= max(1,N). 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
RWORK is DOUBLE PRECISION array, dimension (N)
REC
REC is INTEGER REC indicates the current recursion level. Should be set to 0 on first call.
INFO
INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value
Author
Thijs Steel, KU Leuven
Date
May 2020
Definition at line 230 of file zlaqz2.f.
Author
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