122 SUBROUTINE dgeqr2p( 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(
'DGEQR2P', -info )
175 CALL
dlarfgp( m-i+1, a( i, i ), a( min( i+1, m ), i ), 1,
183 CALL
dlarf(
'Left', m-i+1, n-i, a( i, i ), 1, tau( i ),
184 $ a( i, i+1 ), lda, work )
subroutine dgeqr2p(M, N, A, LDA, TAU, WORK, INFO)
DGEQR2P computes the QR factorization of a general rectangular matrix with non-negative diagonal elem...
subroutine dlarfgp(N, ALPHA, X, INCX, TAU)
DLARFGP generates an elementary reflector (Householder matrix) with non-negatibe beta.
subroutine xerbla(SRNAME, INFO)
XERBLA
subroutine dlarf(SIDE, M, N, V, INCV, TAU, C, LDC, WORK)
DLARF applies an elementary reflector to a general rectangular matrix.