180 SUBROUTINE dgglse( M, N, P, A, LDA, B, LDB, C, D, X, WORK, LWORK,
189 INTEGER INFO, LDA, LDB, LWORK, M, N, P
192 DOUBLE PRECISION A( lda, * ), B( ldb, * ), C( * ), D( * ),
200 parameter ( one = 1.0d+0 )
204 INTEGER LOPT, LWKMIN, LWKOPT, MN, NB, NB1, NB2, NB3,
216 INTRINSIC int, max, min
224 lquery = ( lwork.EQ.-1 )
227 ELSE IF( n.LT.0 )
THEN
229 ELSE IF( p.LT.0 .OR. p.GT.n .OR. p.LT.n-m )
THEN
231 ELSE IF( lda.LT.max( 1, m ) )
THEN
233 ELSE IF( ldb.LT.max( 1, p ) )
THEN
244 nb1 = ilaenv( 1,
'DGEQRF',
' ', m, n, -1, -1 )
245 nb2 = ilaenv( 1,
'DGERQF',
' ', m, n, -1, -1 )
246 nb3 = ilaenv( 1,
'DORMQR',
' ', m, n, p, -1 )
247 nb4 = ilaenv( 1,
'DORMRQ',
' ', m, n, p, -1 )
248 nb = max( nb1, nb2, nb3, nb4 )
250 lwkopt = p + mn + max( m, n )*nb
254 IF( lwork.LT.lwkmin .AND. .NOT.lquery )
THEN
260 CALL xerbla(
'DGGLSE', -info )
262 ELSE IF( lquery )
THEN
280 CALL dggrqf( p, m, n, b, ldb, work, a, lda, work( p+1 ),
281 $ work( p+mn+1 ), lwork-p-mn, info )
282 lopt = work( p+mn+1 )
287 CALL dormqr(
'Left',
'Transpose', m, 1, mn, a, lda, work( p+1 ),
288 $ c, max( 1, m ), work( p+mn+1 ), lwork-p-mn, info )
289 lopt = max( lopt, int( work( p+mn+1 ) ) )
294 CALL dtrtrs(
'Upper',
'No transpose',
'Non-unit', p, 1,
295 $ b( 1, n-p+1 ), ldb, d, p, info )
304 CALL dcopy( p, d, 1, x( n-p+1 ), 1 )
308 CALL dgemv(
'No transpose', n-p, p, -one, a( 1, n-p+1 ), lda,
315 CALL dtrtrs(
'Upper',
'No transpose',
'Non-unit', n-p, 1,
316 $ a, lda, c, n-p, info )
325 CALL dcopy( n-p, c, 1, x, 1 )
333 $
CALL dgemv(
'No transpose', nr, n-m, -one, a( n-p+1, m+1 ),
334 $ lda, d( nr+1 ), 1, one, c( n-p+1 ), 1 )
339 CALL dtrmv(
'Upper',
'No transpose',
'Non unit', nr,
340 $ a( n-p+1, n-p+1 ), lda, d, 1 )
341 CALL daxpy( nr, -one, d, 1, c( n-p+1 ), 1 )
346 CALL dormrq(
'Left',
'Transpose', n, 1, p, b, ldb, work( 1 ), x,
347 $ n, work( p+mn+1 ), lwork-p-mn, info )
348 work( 1 ) = p + mn + max( lopt, int( work( p+mn+1 ) ) )
subroutine dggrqf(M, P, N, A, LDA, TAUA, B, LDB, TAUB, WORK, LWORK, INFO)
DGGRQF
subroutine dcopy(N, DX, INCX, DY, INCY)
DCOPY
subroutine dgemv(TRANS, M, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY)
DGEMV
subroutine dormqr(SIDE, TRANS, M, N, K, A, LDA, TAU, C, LDC, WORK, LWORK, INFO)
DORMQR
subroutine daxpy(N, DA, DX, INCX, DY, INCY)
DAXPY
subroutine dtrtrs(UPLO, TRANS, DIAG, N, NRHS, A, LDA, B, LDB, INFO)
DTRTRS
subroutine dgglse(M, N, P, A, LDA, B, LDB, C, D, X, WORK, LWORK, INFO)
DGGLSE solves overdetermined or underdetermined systems for OTHER matrices
subroutine xerbla(SRNAME, INFO)
XERBLA
subroutine dormrq(SIDE, TRANS, M, N, K, A, LDA, TAU, C, LDC, WORK, LWORK, INFO)
DORMRQ
subroutine dtrmv(UPLO, TRANS, DIAG, N, A, LDA, X, INCX)
DTRMV