sopgtr.f(3) LAPACK sopgtr.f(3)NAMEsopgtr.f-
SYNOPSIS
Functions/Subroutines
subroutine sopgtr (UPLO, N, AP, TAU, Q, LDQ, WORK, INFO)
SOPGTR
Function/Subroutine Documentation
subroutine sopgtr (characterUPLO, integerN, real, dimension( * )AP, real,
dimension( * )TAU, real, dimension( ldq, * )Q, integerLDQ, real,
dimension( * )WORK, integerINFO)
SOPGTR
Purpose:
SOPGTR generates a real orthogonal matrix Q which is defined as the
product of n-1 elementary reflectors H(i) of order n, as returned by
SSPTRD 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
= 'U': Upper triangular packed storage used in previous
call to SSPTRD;
= 'L': Lower triangular packed storage used in previous
call to SSPTRD.
N
N is INTEGER
The order of the matrix Q. N >= 0.
AP
AP is REAL array, dimension (N*(N+1)/2)
The vectors which define the elementary reflectors, as
returned by SSPTRD.
TAU
TAU is REAL array, dimension (N-1)
TAU(i) must contain the scalar factor of the elementary
reflector H(i), as returned by SSPTRD.
Q
Q is REAL array, dimension (LDQ,N)
The N-by-N orthogonal matrix Q.
LDQ
LDQ is INTEGER
The leading dimension of the array Q. LDQ >= max(1,N).
WORK
WORK is REAL array, dimension (N-1)
INFO
INFO 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 sopgtr.f.
Author
Generated automatically by Doxygen for LAPACK from the source code.
Version 3.4.2 Sat Nov 16 2013 sopgtr.f(3)
