CUPGTR (3) Linux Manual Page
cupgtr.f –
Synopsis
Functions/Subroutines
subroutine cupgtr (UPLO, N, AP, TAU, Q, LDQ, WORK, INFO)CUPGTR
Function/Subroutine Documentation
subroutine cupgtr (characterUPLO, integerN, complex, dimension( * )AP, complex, dimension( * )TAU, complex, dimension( ldq, * )Q, integerLDQ, complex, dimension( * )WORK, integerINFO)
CUPGTR Purpose:
CUPGTR generates a complex unitary matrix Q which is defined as the
product of n-1 elementary reflectors H(i) of order n, as returned by
CHPTRD using packed storage:
if UPLO = ‘U’, Q = H(n-1) . . . H(2) H(1),
if UPLO = ‘L’, Q = H(1) H(2) . . . H(n-1).
Parameters:
- UPLO
UPLO is CHARACTER*1
N
= ‘U’: Upper triangular packed storage used in previous
call to CHPTRD;
= ‘L’: Lower triangular packed storage used in previous
call to CHPTRD.N is INTEGER
AP
The order of the matrix Q. N >= 0.AP is COMPLEX array, dimension (N*(N+1)/2)
TAU
The vectors which define the elementary reflectors, as
returned by CHPTRD.TAU is COMPLEX array, dimension (N-1)
Q
TAU(i) must contain the scalar factor of the elementary
reflector H(i), as returned by CHPTRD.Q is COMPLEX array, dimension (LDQ,N)
LDQ
The N-by-N unitary matrix Q.LDQ is INTEGER
WORK
The leading dimension of the array Q. LDQ >= max(1,N).WORK is COMPLEX array, dimension (N-1)
INFOINFO is INTEGER
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value
Author:
- Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
- November 2011
Definition at line 115 of file cupgtr.f.
