140 SUBROUTINE dgelqt( M, N, MB, A, LDA, T, LDT, WORK, INFO )
148 INTEGER INFO, LDA, LDT, M, N, MB
151 DOUBLE PRECISION A( lda, * ), T( ldt, * ), WORK( * )
158 INTEGER I, IB, IINFO, K
170 ELSE IF( n.LT.0 )
THEN
172 ELSE IF( mb.LT.1 .OR. ( mb.GT.min(m,n) .AND. min(m,n).GT.0 ) )
THEN
174 ELSE IF( lda.LT.max( 1, m ) )
THEN
176 ELSE IF( ldt.LT.mb )
THEN
180 CALL xerbla(
'DGELQT', -info )
192 ib = min( k-i+1, mb )
196 CALL dgelqt3( ib, n-i+1, a(i,i), lda, t(1,i), ldt, iinfo )
201 CALL dlarfb(
'R',
'N',
'F',
'R', m-i-ib+1, n-i+1, ib,
202 $ a( i, i ), lda, t( 1, i ), ldt,
203 $ a( i+ib, i ), lda, work , m-i-ib+1 )
subroutine dlarfb(SIDE, TRANS, DIRECT, STOREV, M, N, K, V, LDV, T, LDT, C, LDC, WORK, LDWORK)
DLARFB applies a block reflector or its transpose to a general rectangular matrix.
recursive subroutine dgeqrt3(M, N, A, LDA, T, LDT, INFO)
DGEQRT3 recursively computes a QR factorization of a general real or complex matrix using the compact...
subroutine xerbla(SRNAME, INFO)
XERBLA
recursive subroutine dgelqt3(M, N, A, LDA, T, LDT, INFO)
DGELQT3 recursively computes a LQ factorization of a general real or complex matrix using the compact...
subroutine dgeqrt2(M, N, A, LDA, T, LDT, INFO)
DGEQRT2 computes a QR factorization of a general real or complex matrix using the compact WY represen...
subroutine dgelqt(M, N, MB, A, LDA, T, LDT, WORK, INFO)
DGELQT