.TH "SRC/dlaqz1.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*-
.ad l
.nh
.SH NAME
SRC/dlaqz1.f
.SH SYNOPSIS
.br
.PP
.SS "Functions/Subroutines"

.in +1c
.ti -1c
.RI "subroutine \fBdlaqz1\fP (a, lda, b, ldb, sr1, sr2, si, beta1, beta2, v)"
.br
.RI "\fBDLAQZ1\fP "
.in -1c
.SH "Function/Subroutine Documentation"
.PP 
.SS "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)"

.PP
\fBDLAQZ1\fP  
.PP
\fBPurpose:\fP
.RS 4

.PP
.nf
!>
!>      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\&.
!> 
.fi
.PP
 
.RE
.PP
\fBParameters\fP
.RS 4
\fIA\fP 
.PP
.nf
!>          A is DOUBLE PRECISION array, dimension (LDA,N)
!>              The 3-by-3 matrix A in (*)\&.
!> 
.fi
.PP
.br
\fILDA\fP 
.PP
.nf
!>          LDA is INTEGER
!>              The leading dimension of A as declared in
!>              the calling procedure\&.
!> 
.fi
.PP
 
.br
\fIB\fP 
.PP
.nf
!>          B is DOUBLE PRECISION array, dimension (LDB,N)
!>              The 3-by-3 matrix B in (*)\&.
!> 
.fi
.PP
.br
\fILDB\fP 
.PP
.nf
!>          LDB is INTEGER
!>              The leading dimension of B as declared in
!>              the calling procedure\&.
!> 
.fi
.PP
.br
\fISR1\fP 
.PP
.nf
!>          SR1 is DOUBLE PRECISION
!> 
.fi
.PP
.br
\fISR2\fP 
.PP
.nf
!>          SR2 is DOUBLE PRECISION
!> 
.fi
.PP
.br
\fISI\fP 
.PP
.nf
!>          SI is DOUBLE PRECISION
!> 
.fi
.PP
.br
\fIBETA1\fP 
.PP
.nf
!>          BETA1 is DOUBLE PRECISION
!> 
.fi
.PP
.br
\fIBETA2\fP 
.PP
.nf
!>          BETA2 is DOUBLE PRECISION
!> 
.fi
.PP
.br
\fIV\fP 
.PP
.nf
!>          V is DOUBLE PRECISION array, dimension (N)
!>              A scalar multiple of the first column of the
!>              matrix K in (*)\&.
!> 
.fi
.PP
 
.RE
.PP
\fBAuthor\fP
.RS 4
Thijs Steel, KU Leuven 
.RE
.PP
\fBDate\fP
.RS 4
May 2020 
.RE
.PP

.PP
Definition at line \fB125\fP of file \fBdlaqz1\&.f\fP\&.
.SH "Author"
.PP 
Generated automatically by Doxygen for LAPACK from the source code\&.