sopgtr.f (3) Linux Manual Page
sopgtr.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
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