185 SUBROUTINE dggglm( N, M, P, A, LDA, B, LDB, D, X, Y, WORK, LWORK,
194 INTEGER INFO, LDA, LDB, LWORK, M, N, P
197 DOUBLE PRECISION A( lda, * ), B( ldb, * ), D( * ), WORK( * ),
204 DOUBLE PRECISION ZERO, ONE
205 parameter ( zero = 0.0d+0, one = 1.0d+0 )
209 INTEGER I, LOPT, LWKMIN, LWKOPT, NB, NB1, NB2, NB3,
221 INTRINSIC int, max, min
229 lquery = ( lwork.EQ.-1 )
232 ELSE IF( m.LT.0 .OR. m.GT.n )
THEN
234 ELSE IF( p.LT.0 .OR. p.LT.n-m )
THEN
236 ELSE IF( lda.LT.max( 1, n ) )
THEN
238 ELSE IF( ldb.LT.max( 1, n ) )
THEN
249 nb1 = ilaenv( 1,
'DGEQRF',
' ', n, m, -1, -1 )
250 nb2 = ilaenv( 1,
'DGERQF',
' ', n, m, -1, -1 )
251 nb3 = ilaenv( 1,
'DORMQR',
' ', n, m, p, -1 )
252 nb4 = ilaenv( 1,
'DORMRQ',
' ', n, m, p, -1 )
253 nb = max( nb1, nb2, nb3, nb4 )
255 lwkopt = m + np + max( n, p )*nb
259 IF( lwork.LT.lwkmin .AND. .NOT.lquery )
THEN
265 CALL xerbla(
'DGGGLM', -info )
267 ELSE IF( lquery )
THEN
285 CALL dggqrf( n, m, p, a, lda, work, b, ldb, work( m+1 ),
286 $ work( m+np+1 ), lwork-m-np, info )
287 lopt = work( m+np+1 )
292 CALL dormqr(
'Left',
'Transpose', n, 1, m, a, lda, work, d,
293 $ max( 1, n ), work( m+np+1 ), lwork-m-np, info )
294 lopt = max( lopt, int( work( m+np+1 ) ) )
299 CALL dtrtrs(
'Upper',
'No transpose',
'Non unit', n-m, 1,
300 $ b( m+1, m+p-n+1 ), ldb, d( m+1 ), n-m, info )
307 CALL dcopy( n-m, d( m+1 ), 1, y( m+p-n+1 ), 1 )
312 DO 10 i = 1, m + p - n
318 CALL dgemv(
'No transpose', m, n-m, -one, b( 1, m+p-n+1 ), ldb,
319 $ y( m+p-n+1 ), 1, one, d, 1 )
324 CALL dtrtrs(
'Upper',
'No Transpose',
'Non unit', m, 1, a, lda,
334 CALL dcopy( m, d, 1, x, 1 )
339 CALL dormrq(
'Left',
'Transpose', p, 1, np,
340 $ b( max( 1, n-p+1 ), 1 ), ldb, work( m+1 ), y,
341 $ max( 1, p ), work( m+np+1 ), lwork-m-np, info )
342 work( 1 ) = m + np + max( lopt, int( work( m+np+1 ) ) )
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 dtrtrs(UPLO, TRANS, DIAG, N, NRHS, A, LDA, B, LDB, INFO)
DTRTRS
subroutine xerbla(SRNAME, INFO)
XERBLA
subroutine dggglm(N, M, P, A, LDA, B, LDB, D, X, Y, WORK, LWORK, INFO)
DGGGLM
subroutine dggqrf(N, M, P, A, LDA, TAUA, B, LDB, TAUB, WORK, LWORK, INFO)
DGGQRF
subroutine dormrq(SIDE, TRANS, M, N, K, A, LDA, TAU, C, LDC, WORK, LWORK, INFO)
DORMRQ