101 SUBROUTINE dgetrf ( M, N, A, LDA, IPIV, INFO)
109 INTEGER info, lda, m, n
113 DOUBLE PRECISION a( lda, * )
120 parameter( one = 1.0d+0 )
123 INTEGER i, iinfo,
j, jb, nb
142 ELSE IF( n.LT.0 )
THEN
144 ELSE IF( lda.LT.max( 1, m ) )
THEN
148 CALL
xerbla(
'DGETRF', -info )
154 IF( m.EQ.0 .OR. n.EQ.0 )
159 nb =
ilaenv( 1,
'DGETRF',
' ', m, n, -1, -1 )
160 IF( nb.LE.1 .OR. nb.GE.min( m, n ) )
THEN
164 CALL
dgetf2( m, n, a, lda, ipiv, info )
169 DO 20
j = 1, min( m, n ), nb
170 jb = min( min( m, n )-
j+1, nb )
174 CALL
dgemm(
'No transpose',
'No transpose',
175 $ m-
j+1, jb,
j-1, -one,
176 $ a(
j, 1 ), lda, a( 1,
j ), lda, one,
183 CALL
dgetf2( m-
j+1, jb, a(
j,
j ), lda, ipiv(
j ), iinfo )
187 IF( info.EQ.0 .AND. iinfo.GT.0 )
188 $ info = iinfo +
j - 1
189 DO 10 i =
j, min( m,
j+jb-1 )
190 ipiv( i ) =
j - 1 + ipiv( i )
195 CALL
dlaswp(
j-1, a, lda,
j,
j+jb-1, ipiv, 1 )
197 IF (
j+jb.LE.n )
THEN
201 CALL
dlaswp( n-
j-jb+1, a( 1,
j+jb ), lda,
j,
j+jb-1,
204 CALL
dgemm(
'No transpose',
'No transpose',
205 $ jb, n-
j-jb+1,
j-1, -one,
206 $ a(
j, 1 ), lda, a( 1,
j+jb ), lda, one,
207 $ a(
j,
j+jb ), lda )
211 CALL
dtrsm(
'Left',
'Lower',
'No transpose',
'Unit',
212 $ jb, n-
j-jb+1, one, a(
j,
j ), lda,
213 $ a(
j,
j+jb ), lda )
subroutine dlaswp(N, A, LDA, K1, K2, IPIV, INCX)
DLASWP performs a series of row interchanges on a general rectangular matrix.
subroutine dgemm(TRANSA, TRANSB, M, N, K, ALPHA, A, LDA, B, LDB, BETA, C, LDC)
DGEMM
subroutine xerbla(SRNAME, INFO)
XERBLA
subroutine dtrsm(SIDE, UPLO, TRANSA, DIAG, M, N, ALPHA, A, LDA, B, LDB)
DTRSM
subroutine dgetf2(M, N, A, LDA, IPIV, INFO)
DGETF2 computes the LU factorization of a general m-by-n matrix using partial pivoting with row inter...
set ue cd $ADTTMP cat<< EOF > tmp f Program LinearEquations Implicit none Real j
integer function ilaenv(ISPEC, NAME, OPTS, N1, N2, N3, N4)
subroutine dgetrf(M, N, A, LDA, IPIV, INFO)
DGETRF