125 SUBROUTINE sgeqr2p( M, N, A, LDA, TAU, WORK, INFO )
133 INTEGER INFO, LDA, M, N
136 REAL A( lda, * ), TAU( * ), WORK( * )
143 parameter ( one = 1.0e+0 )
162 ELSE IF( n.LT.0 )
THEN
164 ELSE IF( lda.LT.max( 1, m ) )
THEN
168 CALL xerbla(
'SGEQR2P', -info )
178 CALL slarfgp( m-i+1, a( i, i ), a( min( i+1, m ), i ), 1,
186 CALL slarf(
'Left', m-i+1, n-i, a( i, i ), 1, tau( i ),
187 $ a( i, i+1 ), lda, work )
subroutine sgeqr2p(M, N, A, LDA, TAU, WORK, INFO)
SGEQR2P computes the QR factorization of a general rectangular matrix with non-negative diagonal elem...
subroutine xerbla(SRNAME, INFO)
XERBLA
subroutine slarfgp(N, ALPHA, X, INCX, TAU)
SLARFGP generates an elementary reflector (Householder matrix) with non-negative beta.
subroutine slarf(SIDE, M, N, V, INCV, TAU, C, LDC, WORK)
SLARF applies an elementary reflector to a general rectangular matrix.