166 SUBROUTINE sormqr( SIDE, TRANS, M, N, K, A, LDA, TAU, C, LDC,
167 $ WORK, LWORK, INFO )
174 CHARACTER SIDE, TRANS
175 INTEGER INFO, K, LDA, LDC, LWORK, M, N
178 REAL A( LDA, * ), C( LDC, * ), TAU( * ),
185 INTEGER NBMAX, LDT, TSIZE
186 parameter( nbmax = 64, ldt = nbmax+1,
187 $ tsize = ldt*nbmax )
190 LOGICAL LEFT, LQUERY, NOTRAN
191 INTEGER I, I1, I2, I3, IB, IC, IINFO, IWT, JC, LDWORK,
192 $ lwkopt, mi, nb, nbmin, ni, nq, nw
197 EXTERNAL lsame, ilaenv
210 left = lsame( side,
'L' )
211 notran = lsame( trans,
'N' )
212 lquery = ( lwork.EQ.-1 )
223 IF( .NOT.left .AND. .NOT.lsame( side,
'R' ) )
THEN
225 ELSE IF( .NOT.notran .AND. .NOT.lsame( trans,
'T' ) )
THEN
227 ELSE IF( m.LT.0 )
THEN
229 ELSE IF( n.LT.0 )
THEN
231 ELSE IF( k.LT.0 .OR. k.GT.nq )
THEN
233 ELSE IF( lda.LT.max( 1, nq ) )
THEN
235 ELSE IF( ldc.LT.max( 1, m ) )
THEN
237 ELSE IF( lwork.LT.nw .AND. .NOT.lquery )
THEN
245 nb = min( nbmax, ilaenv( 1,
'SORMQR', side // trans, m, n, k,
247 lwkopt = nw*nb + tsize
252 CALL xerbla(
'SORMQR', -info )
254 ELSE IF( lquery )
THEN
260 IF( m.EQ.0 .OR. n.EQ.0 .OR. k.EQ.0 )
THEN
267 IF( nb.GT.1 .AND. nb.LT.k )
THEN
268 IF( lwork.LT.lwkopt )
THEN
269 nb = (lwork-tsize) / ldwork
270 nbmin = max( 2, ilaenv( 2,
'SORMQR', side // trans, m, n, k,
275 IF( nb.LT.nbmin .OR. nb.GE.k )
THEN
279 CALL sorm2r( side, trans, m, n, k, a, lda, tau, c, ldc, work,
286 IF( ( left .AND. .NOT.notran ) .OR.
287 $ ( .NOT.left .AND. notran ) )
THEN
292 i1 = ( ( k-1 ) / nb )*nb + 1
306 ib = min( nb, k-i+1 )
311 CALL slarft(
'Forward',
'Columnwise', nq-i+1, ib, a( i, i ),
312 $ lda, tau( i ), work( iwt ), ldt )
329 CALL slarfb( side, trans,
'Forward',
'Columnwise', mi, ni,
330 $ ib, a( i, i ), lda, work( iwt ), ldt,
331 $ c( ic, jc ), ldc, work, ldwork )
subroutine xerbla(SRNAME, INFO)
XERBLA
subroutine slarfb(SIDE, TRANS, DIRECT, STOREV, M, N, K, V, LDV, T, LDT, C, LDC, WORK, LDWORK)
SLARFB applies a block reflector or its transpose to a general rectangular matrix.
subroutine slarft(DIRECT, STOREV, N, K, V, LDV, TAU, T, LDT)
SLARFT forms the triangular factor T of a block reflector H = I - vtvH
subroutine sorm2r(SIDE, TRANS, M, N, K, A, LDA, TAU, C, LDC, WORK, INFO)
SORM2R multiplies a general matrix by the orthogonal matrix from a QR factorization determined by sge...
subroutine sormqr(SIDE, TRANS, M, N, K, A, LDA, TAU, C, LDC, WORK, LWORK, INFO)
SORMQR