215 SUBROUTINE dggqrf( N, M, P, A, LDA, TAUA, B, LDB, TAUB, WORK,
224 INTEGER info, lda, ldb, lwork, m, n, p
227 DOUBLE PRECISION a( lda, * ),
b( ldb, * ), taua( * ), taub( * ),
235 INTEGER lopt, lwkopt, nb, nb1, nb2, nb3
245 INTRINSIC int, max, min
252 nb1 =
ilaenv( 1,
'DGEQRF',
' ', n, m, -1, -1 )
253 nb2 =
ilaenv( 1,
'DGERQF',
' ', n, p, -1, -1 )
254 nb3 =
ilaenv( 1,
'DORMQR',
' ', n, m, p, -1 )
255 nb = max( nb1, nb2, nb3 )
256 lwkopt = max( n, m, p )*nb
258 lquery = ( lwork.EQ.-1 )
261 ELSE IF( m.LT.0 )
THEN
263 ELSE IF( p.LT.0 )
THEN
265 ELSE IF( lda.LT.max( 1, n ) )
THEN
267 ELSE IF( ldb.LT.max( 1, n ) )
THEN
269 ELSE IF( lwork.LT.max( 1, n, m, p ) .AND. .NOT.lquery )
THEN
273 CALL
xerbla(
'DGGQRF', -info )
275 ELSE IF( lquery )
THEN
281 CALL
dgeqrf( n, m, a, lda, taua, work, lwork, info )
286 CALL
dormqr(
'Left',
'Transpose', n, p, min( n, m ), a, lda, taua,
287 $
b, ldb, work, lwork, info )
288 lopt = max( lopt, int( work( 1 ) ) )
292 CALL
dgerqf( n, p,
b, ldb, taub, work, lwork, info )
293 work( 1 ) = max( lopt, int( work( 1 ) ) )
subroutine dgeqrf(M, N, A, LDA, TAU, WORK, LWORK, INFO)
DGEQRF
subroutine dormqr(SIDE, TRANS, M, N, K, A, LDA, TAU, C, LDC, WORK, LWORK, INFO)
DORMQR
subroutine xerbla(SRNAME, INFO)
XERBLA
set ue cd $ADTTMP cat<< EOF > tmp f Program LinearEquations Implicit none Real b(3) integer i
subroutine dggqrf(N, M, P, A, LDA, TAUA, B, LDB, TAUB, WORK, LWORK, INFO)
DGGQRF
subroutine dgerqf(M, N, A, LDA, TAU, WORK, LWORK, INFO)
DGERQF
integer function ilaenv(ISPEC, NAME, OPTS, N1, N2, N3, N4)