SRC/zlaqz3.f(3)

Library Functions Manual

SRC/zlaqz3.f(3)

NAME

SRC/zlaqz3.f

SYNOPSIS

Functions/Subroutines

subroutine zlaqz3 (ilschur, ilq, ilz, n, ilo, ihi, nshifts, nblock_desired, alpha, beta, a, lda, b, ldb, q, ldq, z, ldz, qc, ldqc, zc, ldzc, work, lwork, info)
ZLAQZ3

Function/Subroutine Documentation

subroutine zlaqz3 (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, complex16, dimension( ), intent(inout) alpha, complex16, dimension( ), intent(inout) beta, complex16, dimension( lda, ), intent(inout) a, integer, intent(in) lda, complex16, dimension( ldb, ), intent(inout) b, integer, intent(in) ldb, complex16, dimension( ldq, ), intent(inout) q, integer, intent(in) ldq, complex16, dimension( ldz, ), intent(inout) z, integer, intent(in) ldz, complex16, dimension( ldqc, ), intent(inout) qc, integer, intent(in) ldqc, complex16, dimension( ldzc, ), intent(inout) zc, integer, intent(in) ldzc, complex16, dimension( ), intent(inout) work, integer, intent(in) lwork, integer, intent(out) info)

ZLAQZ3

Purpose:

 ZLAQZ3 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 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

ALPHA

          ALPHA is COMPLEX*16 array. SR contains
          the alpha parts of the shifts to use.

BETA

          BETA is COMPLEX*16 array. SS contains
          the scale of the shifts to use.

          A is COMPLEX*16 array, dimension (LDA, N)

LDA

          LDA is INTEGER
          The leading dimension of the array A.  LDA >= max( 1, N ).

          B is COMPLEX*16 array, dimension (LDB, N)

LDB

          LDB is INTEGER
          The leading dimension of the array B.  LDB >= max( 1, N ).

          Q is COMPLEX*16 array, dimension (LDQ, N)

LDQ

          LDQ is INTEGER

          Z is COMPLEX*16 array, dimension (LDZ, N)

LDZ

          LDZ is INTEGER

          QC is COMPLEX*16 array, dimension (LDQC, NBLOCK_DESIRED)

LDQC

          LDQC is INTEGER

          ZC is COMPLEX*16 array, dimension (LDZC, NBLOCK_DESIRED)

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.

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 204 of file zlaqz3.f.

Author

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