ZUNML2(3) LAPACK routine of NEC Numeric Library Collection ZUNML2(3)
NAME
ZUNML2
SYNOPSIS
SUBROUTINE ZUNML2 (SIDE, TRANS, M, N, K, A, LDA, TAU, C, LDC, WORK,
INFO)
PURPOSE
ZUNML2 overwrites the general complex m-by-n matrix C with
Q * C if SIDE = 'L' and TRANS = 'N', or
Q**H* C if SIDE = 'L' and TRANS = 'C', or
C * Q if SIDE = 'R' and TRANS = 'N', or
C * Q**H if SIDE = 'R' and TRANS = 'C',
where Q is a complex unitary matrix defined as the product of k
elementary reflectors
Q = H(k)**H . . . H(2)**H H(1)**H
as returned by ZGELQF. Q is of order m if SIDE = 'L' and of order n
if SIDE = 'R'.
ARGUMENTS
SIDE (input)
SIDE is CHARACTER*1
= 'L': apply Q or Q**H from the Left
= 'R': apply Q or Q**H from the Right
TRANS (input)
TRANS is CHARACTER*1
= 'N': apply Q (No transpose)
= 'C': apply Q**H (Conjugate transpose)
M (input)
M is INTEGER
The number of rows of the matrix C. M >= 0.
N (input)
N is INTEGER
The number of columns of the matrix C. N >= 0.
K (input)
K is INTEGER
The number of elementary reflectors whose product defines
the matrix Q.
If SIDE = 'L', M >= K >= 0;
if SIDE = 'R', N >= K >= 0.
A (input)
A is COMPLEX*16 array, dimension
(LDA,M) if SIDE = 'L',
(LDA,N) if SIDE = 'R'
The i-th row must contain the vector which defines the
elementary reflector H(i), for i = 1,2,...,k, as returned by
ZGELQF in the first k rows of its array argument A.
A is modified by the routine but restored on exit.
LDA (input)
LDA is INTEGER
The leading dimension of the array A. LDA >= max(1,K).
TAU (input)
TAU is COMPLEX*16 array, dimension (K)
TAU(i) must contain the scalar factor of the elementary
reflector H(i), as returned by ZGELQF.
C (input/output)
C is COMPLEX*16 array, dimension (LDC,N)
On entry, the m-by-n matrix C.
On exit, C is overwritten by Q*C or Q**H*C or C*Q**H or C*Q.
LDC (input)
LDC is INTEGER
The leading dimension of the array C. LDC >= max(1,M).
WORK (output)
WORK is COMPLEX*16 array, dimension
(N) if SIDE = 'L',
(M) if SIDE = 'R'
INFO (output)
INFO is INTEGER
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value
LAPACK routine 31 October 2017 ZUNML2(3)