ztrexc.f(3) LAPACK ztrexc.f(3)
subroutine ztrexc (COMPQ, N, T, LDT, Q, LDQ, IFST, ILST, INFO)
subroutine ztrexc (characterCOMPQ, integerN, complex*16, dimension( ldt, * )T, integerLDT,
complex*16, dimension( ldq, * )Q, integerLDQ, integerIFST, integerILST, integerINFO)
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.
COMPQ is CHARACTER*1
= 'V': update the matrix Q of Schur vectors;
= 'N': do not update Q.
N is INTEGER
The order of the matrix T. N >= 0.
T is COMPLEX*16 array, dimension (LDT,N)
On entry, the upper triangular matrix T.
On exit, the reordered upper triangular matrix.
LDT is INTEGER
The leading dimension of the array T. LDT >= max(1,N).
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.
LDQ is INTEGER
The leading dimension of the array Q. LDQ >= max(1,N).
IFST is INTEGER
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.
INFO is INTEGER
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
Definition at line 125 of file ztrexc.f.
Generated automatically by Doxygen for LAPACK from the source code.
Version 3.4.2 Tue Sep 25 2012 ztrexc.f(3)