home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
IRIX 6.2 Development Libraries
/
SGI IRIX 6.2 Development Libraries.iso
/
dist
/
complib.idb
/
usr
/
share
/
catman
/
p_man
/
cat3
/
complib
/
zunghr.z
/
zunghr
Wrap
Text File
|
1996-03-14
|
2KB
|
67 lines
ZZZZUUUUNNNNGGGGHHHHRRRR((((3333FFFF)))) ZZZZUUUUNNNNGGGGHHHHRRRR((((3333FFFF))))
NNNNAAAAMMMMEEEE
ZUNGHR - generate a complex unitary matrix Q which is defined as the
product of IHI-ILO elementary reflectors of order N, as returned by
ZGEHRD
SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS
SUBROUTINE ZUNGHR( N, ILO, IHI, A, LDA, TAU, WORK, LWORK, INFO )
INTEGER IHI, ILO, INFO, LDA, LWORK, N
COMPLEX*16 A( LDA, * ), TAU( * ), WORK( LWORK )
PPPPUUUURRRRPPPPOOOOSSSSEEEE
ZUNGHR generates a complex unitary matrix Q which is defined as the
product of IHI-ILO elementary reflectors of order N, as returned by
ZGEHRD:
Q = H(ilo) H(ilo+1) . . . H(ihi-1).
AAAARRRRGGGGUUUUMMMMEEEENNNNTTTTSSSS
N (input) INTEGER
The order of the matrix Q. N >= 0.
ILO (input) INTEGER
IHI (input) INTEGER ILO and IHI must have the same values as
in the previous call of ZGEHRD. Q is equal to the unit matrix
except in the submatrix Q(ilo+1:ihi,ilo+1:ihi). 1 <= ILO <= IHI
<= N, if N > 0; ILO=1 and IHI=0, if N=0.
A (input/output) COMPLEX*16 array, dimension (LDA,N)
On entry, the vectors which define the elementary reflectors, as
returned by ZGEHRD. On exit, the N-by-N unitary matrix Q.
LDA (input) INTEGER
The leading dimension of the array A. LDA >= max(1,N).
TAU (input) COMPLEX*16 array, dimension (N-1)
TAU(i) must contain the scalar factor of the elementary reflector
H(i), as returned by ZGEHRD.
WORK (workspace/output) COMPLEX*16 array, dimension (LWORK)
On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
LWORK (input) INTEGER
The dimension of the array WORK. LWORK >= IHI-ILO. For optimum
performance LWORK >= (IHI-ILO)*NB, where NB is the optimal
blocksize.
INFO (output) INTEGER
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value
PPPPaaaaggggeeee 1111