.TH "ztrexc.f" 3 "Tue Nov 14 2017" "Version 3.8.0" "LAPACK" \" -*- nroff -*-
.ad l
.nh
.SH NAME
ztrexc.f
.SH SYNOPSIS
.br
.PP
.SS "Functions/Subroutines"

.in +1c
.ti -1c
.RI "subroutine \fBztrexc\fP (COMPQ, \fBN\fP, T, LDT, Q, LDQ, IFST, ILST, INFO)"
.br
.RI "\fBZTREXC\fP "
.in -1c
.SH "Function/Subroutine Documentation"
.PP 
.SS "subroutine ztrexc (character COMPQ, integer N, complex*16, dimension( ldt, * ) T, integer LDT, complex*16, dimension( ldq, * ) Q, integer LDQ, integer IFST, integer ILST, integer INFO)"

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

.PP
.nf
 ZTREXC reorders the Schur factorization of a complex matrix
 A = Q*T*Q**H, so that the diagonal element of T with row index IFST
 is moved to row ILST.

 The Schur form T is reordered by a unitary similarity transformation
 Z**H*T*Z, and optionally the matrix Q of Schur vectors is updated by
 postmultplying it with Z.
.fi
.PP
 
.RE
.PP
\fBParameters:\fP
.RS 4
\fICOMPQ\fP 
.PP
.nf
          COMPQ is CHARACTER*1
          = 'V':  update the matrix Q of Schur vectors;
          = 'N':  do not update Q.
.fi
.PP
.br
\fIN\fP 
.PP
.nf
          N is INTEGER
          The order of the matrix T. N >= 0.
          If N == 0 arguments ILST and IFST may be any value.
.fi
.PP
.br
\fIT\fP 
.PP
.nf
          T is COMPLEX*16 array, dimension (LDT,N)
          On entry, the upper triangular matrix T.
          On exit, the reordered upper triangular matrix.
.fi
.PP
.br
\fILDT\fP 
.PP
.nf
          LDT is INTEGER
          The leading dimension of the array T. LDT >= max(1,N).
.fi
.PP
.br
\fIQ\fP 
.PP
.nf
          Q is COMPLEX*16 array, dimension (LDQ,N)
          On entry, if COMPQ = 'V', the matrix Q of Schur vectors.
          On exit, if COMPQ = 'V', Q has been postmultiplied by the
          unitary transformation matrix Z which reorders T.
          If COMPQ = 'N', Q is not referenced.
.fi
.PP
.br
\fILDQ\fP 
.PP
.nf
          LDQ is INTEGER
          The leading dimension of the array Q.  LDQ >= 1, and if
          COMPQ = 'V', LDQ >= max(1,N).
.fi
.PP
.br
\fIIFST\fP 
.PP
.nf
          IFST is INTEGER
.fi
.PP
.br
\fIILST\fP 
.PP
.nf
          ILST is INTEGER

          Specify the reordering of the diagonal elements of T:
          The element with row index IFST is moved to row ILST by a
          sequence of transpositions between adjacent elements.
          1 <= IFST <= N; 1 <= ILST <= N.
.fi
.PP
.br
\fIINFO\fP 
.PP
.nf
          INFO is INTEGER
          = 0:  successful exit
          < 0:  if INFO = -i, the i-th argument had an illegal value
.fi
.PP
 
.RE
.PP
\fBAuthor:\fP
.RS 4
Univ\&. of Tennessee 
.PP
Univ\&. of California Berkeley 
.PP
Univ\&. of Colorado Denver 
.PP
NAG Ltd\&. 
.RE
.PP
\fBDate:\fP
.RS 4
December 2016 
.RE
.PP

.PP
Definition at line 128 of file ztrexc\&.f\&.
.SH "Author"
.PP 
Generated automatically by Doxygen for LAPACK from the source code\&.
