124 SUBROUTINE sgeql2( M, N, A, LDA, TAU, WORK, INFO )
132 INTEGER INFO, LDA, M, N
135 REAL A( lda, * ), TAU( * ), WORK( * )
142 parameter ( one = 1.0e+0 )
161 ELSE IF( n.LT.0 )
THEN
163 ELSE IF( lda.LT.max( 1, m ) )
THEN
167 CALL xerbla(
'SGEQL2', -info )
178 CALL slarfg( m-k+i, a( m-k+i, n-k+i ), a( 1, n-k+i ), 1,
183 aii = a( m-k+i, n-k+i )
184 a( m-k+i, n-k+i ) = one
185 CALL slarf(
'Left', m-k+i, n-k+i-1, a( 1, n-k+i ), 1, tau( i ),
187 a( m-k+i, n-k+i ) = aii
subroutine slarfg(N, ALPHA, X, INCX, TAU)
SLARFG generates an elementary reflector (Householder matrix).
subroutine sgeql2(M, N, A, LDA, TAU, WORK, INFO)
SGEQL2 computes the QL factorization of a general rectangular matrix using an unblocked algorithm...
subroutine xerbla(SRNAME, INFO)
XERBLA
subroutine slarf(SIDE, M, N, V, INCV, TAU, C, LDC, WORK)
SLARF applies an elementary reflector to a general rectangular matrix.