
dopgtr.f(3) LAPACK dopgtr.f(3)
NAME
dopgtr.f 
SYNOPSIS
Functions/Subroutines
subroutine dopgtr (UPLO, N, AP, TAU, Q, LDQ, WORK, INFO)
DOPGTR
Function/Subroutine Documentation
subroutine dopgtr (characterUPLO, integerN, double precision, dimension( * )AP, double
precision, dimension( * )TAU, double precision, dimension( ldq, * )Q, integerLDQ, double
precision, dimension( * )WORK, integerINFO)
DOPGTR
Purpose:
DOPGTR generates a real orthogonal matrix Q which is defined as the
product of n1 elementary reflectors H(i) of order n, as returned by
DSPTRD using packed storage:
if UPLO = 'U', Q = H(n1) . . . H(2) H(1),
if UPLO = 'L', Q = H(1) H(2) . . . H(n1).
Parameters:
UPLO
UPLO is CHARACTER*1
= 'U': Upper triangular packed storage used in previous
call to DSPTRD;
= 'L': Lower triangular packed storage used in previous
call to DSPTRD.
N
N is INTEGER
The order of the matrix Q. N >= 0.
AP
AP is DOUBLE PRECISION array, dimension (N*(N+1)/2)
The vectors which define the elementary reflectors, as
returned by DSPTRD.
TAU
TAU is DOUBLE PRECISION array, dimension (N1)
TAU(i) must contain the scalar factor of the elementary
reflector H(i), as returned by DSPTRD.
Q
Q is DOUBLE PRECISION array, dimension (LDQ,N)
The NbyN orthogonal matrix Q.
LDQ
LDQ is INTEGER
The leading dimension of the array Q. LDQ >= max(1,N).
WORK
WORK is DOUBLE PRECISION array, dimension (N1)
INFO
INFO is INTEGER
= 0: successful exit
< 0: if INFO = i, the ith 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 dopgtr.f.
Author
Generated automatically by Doxygen for LAPACK from the source code.
Version 3.4.2 Tue Sep 25 2012 dopgtr.f(3) 
