SRC/dlaqz1.f(3)            Library Functions Manual            SRC/dlaqz1.f(3)

NAME
       SRC/dlaqz1.f

SYNOPSIS
   Functions/Subroutines
       subroutine dlaqz1 (a, lda, b, ldb, sr1, sr2, si, beta1, beta2, v)
           DLAQZ1

Function/Subroutine Documentation
   subroutine dlaqz1 (double precision, dimension( lda, * ), intent(in) a,
       integer, intent(in) lda, double precision, dimension( ldb, * ),
       intent(in) b, integer, intent(in) ldb, double precision, intent(in)
       sr1, double precision, intent(in) sr2, double precision, intent(in) si,
       double precision, intent(in) beta1, double precision, intent(in) beta2,
       double precision, dimension( * ), intent(out) v)
       DLAQZ1

       Purpose:


           !>
           !>      Given a 3-by-3 matrix pencil (A,B), DLAQZ1 sets v to a
           !>      scalar multiple of the first column of the product
           !>
           !>      (*)  K = (A - (beta2*sr2 - i*si)*B)*B^(-1)*(beta1*A - (sr2 + i*si2)*B)*B^(-1).
           !>
           !>      It is assumed that either
           !>
           !>              1) sr1 = sr2
           !>          or
           !>              2) si = 0.
           !>
           !>      This is useful for starting double implicit shift bulges
           !>      in the QZ algorithm.
           !>

       Parameters
           A

           !>          A is DOUBLE PRECISION array, dimension (LDA,N)
           !>              The 3-by-3 matrix A in (*).
           !>

           LDA

           !>          LDA is INTEGER
           !>              The leading dimension of A as declared in
           !>              the calling procedure.
           !>

           B

           !>          B is DOUBLE PRECISION array, dimension (LDB,N)
           !>              The 3-by-3 matrix B in (*).
           !>

           LDB

           !>          LDB is INTEGER
           !>              The leading dimension of B as declared in
           !>              the calling procedure.
           !>

           SR1

           !>          SR1 is DOUBLE PRECISION
           !>

           SR2

           !>          SR2 is DOUBLE PRECISION
           !>

           SI

           !>          SI is DOUBLE PRECISION
           !>

           BETA1

           !>          BETA1 is DOUBLE PRECISION
           !>

           BETA2

           !>          BETA2 is DOUBLE PRECISION
           !>

           V

           !>          V is DOUBLE PRECISION array, dimension (N)
           !>              A scalar multiple of the first column of the
           !>              matrix K in (*).
           !>

       Author
           Thijs Steel, KU Leuven

       Date
           May 2020

       Definition at line 125 of file dlaqz1.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

LAPACK                          Version 3.12.0                 SRC/dlaqz1.f(3)