121 SUBROUTINE sgeqrs( M, N, NRHS, A, LDA, TAU, B, LDB, WORK, LWORK,
130 INTEGER INFO, LDA, LDB, LWORK, M, N, NRHS
133 REAL A( lda, * ), B( ldb, * ), TAU( * ),
141 parameter ( one = 1.0e+0 )
156 ELSE IF( n.LT.0 .OR. n.GT.m )
THEN
158 ELSE IF( nrhs.LT.0 )
THEN
160 ELSE IF( lda.LT.max( 1, m ) )
THEN
162 ELSE IF( ldb.LT.max( 1, m ) )
THEN
164 ELSE IF( lwork.LT.1 .OR. lwork.LT.nrhs .AND. m.GT.0 .AND. n.GT.0 )
169 CALL xerbla(
'SGEQRS', -info )
175 IF( n.EQ.0 .OR. nrhs.EQ.0 .OR. m.EQ.0 )
180 CALL sormqr(
'Left',
'Transpose', m, nrhs, n, a, lda, tau, b, ldb,
181 $ work, lwork, info )
185 CALL strsm(
'Left',
'Upper',
'No transpose',
'Non-unit', n, nrhs,
186 $ one, a, lda, b, ldb )
subroutine sgeqrs(M, N, NRHS, A, LDA, TAU, B, LDB, WORK, LWORK, INFO)
SGEQRS
subroutine strsm(SIDE, UPLO, TRANSA, DIAG, M, N, ALPHA, A, LDA, B, LDB)
STRSM
subroutine sormqr(SIDE, TRANS, M, N, K, A, LDA, TAU, C, LDC, WORK, LWORK, INFO)
SORMQR
subroutine xerbla(SRNAME, INFO)
XERBLA