122 SUBROUTINE dgelq2( M, N, A, LDA, TAU, WORK, INFO )
130 INTEGER INFO, LDA, M, N
133 DOUBLE PRECISION A( lda, * ), TAU( * ), WORK( * )
140 parameter ( one = 1.0d+0 )
159 ELSE IF( n.LT.0 )
THEN
161 ELSE IF( lda.LT.max( 1, m ) )
THEN
165 CALL xerbla(
'DGELQ2', -info )
175 CALL dlarfg( n-i+1, a( i, i ), a( i, min( i+1, n ) ), lda,
183 CALL dlarf(
'Right', m-i, n-i+1, a( i, i ), lda, tau( i ),
184 $ a( i+1, i ), lda, work )
subroutine dlarf(SIDE, M, N, V, INCV, TAU, C, LDC, WORK)
DLARF applies an elementary reflector to a general rectangular matrix.
subroutine dgelq2(M, N, A, LDA, TAU, WORK, INFO)
DGELQ2 computes the LQ factorization of a general rectangular matrix using an unblocked algorithm...
subroutine xerbla(SRNAME, INFO)
XERBLA
subroutine dlarfg(N, ALPHA, X, INCX, TAU)
DLARFG generates an elementary reflector (Householder matrix).