164 SUBROUTINE dlatsqr( M, N, MB, NB, A, LDA, T, LDT, WORK,
172 INTEGER INFO, LDA, M, N, MB, NB, LDT, LWORK
175 DOUBLE PRECISION A( LDA, * ), WORK( * ), T(LDT, *)
183 INTEGER I, II, KK, CTR
191 INTRINSIC max, min, mod
199 lquery = ( lwork.EQ.-1 )
203 ELSE IF( n.LT.0 .OR. m.LT.n )
THEN
205 ELSE IF( mb.LT.1 )
THEN
207 ELSE IF( nb.LT.1 .OR. ( nb.GT.n .AND. n.GT.0 ))
THEN
209 ELSE IF( lda.LT.max( 1, m ) )
THEN
211 ELSE IF( ldt.LT.nb )
THEN
213 ELSE IF( lwork.LT.(n*nb) .AND. (.NOT.lquery) )
THEN
220 CALL xerbla(
'DLATSQR', -info )
222 ELSE IF (lquery)
THEN
228 IF( min(m,n).EQ.0 )
THEN
234 IF ((mb.LE.n).OR.(mb.GE.m))
THEN
235 CALL dgeqrt( m, n, nb, a, lda, t, ldt, work, info)
239 kk = mod((m-n),(mb-n))
244 CALL dgeqrt( mb, n, nb, a(1,1), lda, t, ldt, work, info )
247 DO i = mb+1, ii-mb+n , (mb-n)
251 CALL dtpqrt( mb-n, n, 0, nb, a(1,1), lda, a( i, 1 ), lda,
260 CALL dtpqrt( kk, n, 0, nb, a(1,1), lda, a( ii, 1 ), lda,
261 $ t(1, ctr * n + 1), ldt,
subroutine dlatsqr(M, N, MB, NB, A, LDA, T, LDT, WORK, LWORK, INFO)
DLATSQR
subroutine xerbla(SRNAME, INFO)
XERBLA
subroutine dgeqrt(M, N, NB, A, LDA, T, LDT, WORK, INFO)
DGEQRT
subroutine dtpqrt(M, N, L, NB, A, LDA, B, LDB, T, LDT, WORK, INFO)
DTPQRT