LAPACK 3.12.0
LAPACK: Linear Algebra PACKage
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◆ sorgl2()

subroutine sorgl2 ( integer m,
integer n,
integer k,
real, dimension( lda, * ) a,
integer lda,
real, dimension( * ) tau,
real, dimension( * ) work,
integer info )

SORGL2

Download SORGL2 + dependencies [TGZ] [ZIP] [TXT]

Purpose:
!>
!> SORGL2 generates an m by n real matrix Q with orthonormal rows,
!> which is defined as the first m rows of a product of k elementary
!> reflectors of order n
!>
!>       Q  =  H(k) . . . H(2) H(1)
!>
!> as returned by SGELQF.
!> 
Parameters
[in]M
!>          M is INTEGER
!>          The number of rows of the matrix Q. M >= 0.
!> 
[in]N
!>          N is INTEGER
!>          The number of columns of the matrix Q. N >= M.
!> 
[in]K
!>          K is INTEGER
!>          The number of elementary reflectors whose product defines the
!>          matrix Q. M >= K >= 0.
!> 
[in,out]A
!>          A is REAL array, dimension (LDA,N)
!>          On entry, the i-th row must contain the vector which defines
!>          the elementary reflector H(i), for i = 1,2,...,k, as returned
!>          by SGELQF in the first k rows of its array argument A.
!>          On exit, the m-by-n matrix Q.
!> 
[in]LDA
!>          LDA is INTEGER
!>          The first dimension of the array A. LDA >= max(1,M).
!> 
[in]TAU
!>          TAU is REAL array, dimension (K)
!>          TAU(i) must contain the scalar factor of the elementary
!>          reflector H(i), as returned by SGELQF.
!> 
[out]WORK
!>          WORK is REAL array, dimension (M)
!> 
[out]INFO
!>          INFO is INTEGER
!>          = 0: successful exit
!>          < 0: if INFO = -i, the i-th argument has an illegal value
!> 
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.