slaqz4.f - Man Page
SRC/slaqz4.f
Synopsis
Functions/Subroutines
subroutine slaqz4 (ilschur, ilq, ilz, n, ilo, ihi, nshifts, nblock_desired, sr, si, ss, a, lda, b, ldb, q, ldq, z, ldz, qc, ldqc, zc, ldzc, work, lwork, info)
SLAQZ4
Function/Subroutine Documentation
subroutine slaqz4 (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) nshifts, integer, intent(in) nblock_desired, real, dimension( * ), intent(inout) sr, real, dimension( * ), intent(inout) si, real, dimension( * ), intent(inout) ss, real, dimension( lda, * ), intent(inout) a, integer, intent(in) lda, real, dimension( ldb, * ), intent(inout) b, integer, intent(in) ldb, real, dimension( ldq, * ), intent(inout) q, integer, intent(in) ldq, real, dimension( ldz, * ), intent(inout) z, integer, intent(in) ldz, real, dimension( ldqc, * ), intent(inout) qc, integer, intent(in) ldqc, real, dimension( ldzc, * ), intent(inout) zc, integer, intent(in) ldzc, real, dimension( * ), intent(inout) work, integer, intent(in) lwork, integer, intent(out) info)
SLAQZ4
Purpose:
SLAQZ4 Executes a single multishift QZ sweep
- 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
NSHIFTS
NSHIFTS is INTEGER The desired number of shifts to use
NBLOCK_DESIRED
NBLOCK_DESIRED is INTEGER The desired size of the computational windows
SR
SR is REAL array. SR contains the real parts of the shifts to use.
SI
SI is REAL array. SI contains the imaginary parts of the shifts to use.
SS
SS is REAL array. SS contains the scale of the shifts to use.
A
A is REAL array, dimension (LDA, N)
LDA
LDA is INTEGER The leading dimension of the array A. LDA >= max( 1, N ).
B
B is REAL array, dimension (LDB, N)
LDB
LDB is INTEGER The leading dimension of the array B. LDB >= max( 1, N ).
Q
Q is REAL array, dimension (LDQ, N)
LDQ
LDQ is INTEGER
Z
Z is REAL array, dimension (LDZ, N)
LDZ
LDZ is INTEGER
QC
QC is REAL array, dimension (LDQC, NBLOCK_DESIRED)
LDQC
LDQC is INTEGER
ZC
ZC is REAL array, dimension (LDZC, NBLOCK_DESIRED)
LDZC
LDZ is INTEGER
WORK
WORK is REAL 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.
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 210 of file slaqz4.f.
Author
Generated automatically by Doxygen for LAPACK from the source code.
Referenced By
The man page slaqz4(3) is an alias of slaqz4.f(3).
Tue Nov 28 2023 12:08:42 Version 3.12.0 LAPACK