101 SUBROUTINE dpotrf ( UPLO, N, A, LDA, INFO )
113 DOUBLE PRECISION A( lda, * )
120 parameter ( one = 1.0d+0 )
129 EXTERNAL lsame, ilaenv
142 upper = lsame( uplo,
'U' )
143 IF( .NOT.upper .AND. .NOT.lsame( uplo,
'L' ) )
THEN
145 ELSE IF( n.LT.0 )
THEN
147 ELSE IF( lda.LT.max( 1, n ) )
THEN
151 CALL xerbla(
'DPOTRF', -info )
162 nb = ilaenv( 1,
'DPOTRF', uplo, n, -1, -1, -1 )
163 IF( nb.LE.1 .OR. nb.GE.n )
THEN
167 CALL dpotf2( uplo, n, a, lda, info )
178 jb = min( nb, n-j+1 )
182 CALL dtrsm(
'Left',
'Upper',
'Transpose',
'Non-unit',
183 $ j-1, jb, one, a( 1, 1 ), lda,
186 CALL dsyrk(
'Upper',
'Transpose', jb, j-1, -one,
188 $ one, a( j, j ), lda )
193 CALL dpotf2(
'Upper', jb, a( j, j ), lda, info )
205 jb = min( nb, n-j+1 )
209 CALL dtrsm(
'Right',
'Lower',
'Transpose',
'Non-unit',
210 $ jb, j-1, one, a( 1, 1 ), lda,
213 CALL dsyrk(
'Lower',
'No Transpose', jb, j-1,
214 $ -one, a( j, 1 ), lda,
215 $ one, a( j, j ), lda )
221 CALL dpotf2(
'Lower', jb, a( j, j ), lda, info )
subroutine dtrsm(SIDE, UPLO, TRANSA, DIAG, M, N, ALPHA, A, LDA, B, LDB)
DTRSM
subroutine dpotrf(UPLO, N, A, LDA, INFO)
DPOTRF
subroutine dgemm(TRANSA, TRANSB, M, N, K, ALPHA, A, LDA, B, LDB, BETA, C, LDC)
DGEMM
subroutine dsyrk(UPLO, TRANS, N, K, ALPHA, A, LDA, BETA, C, LDC)
DSYRK
subroutine xerbla(SRNAME, INFO)
XERBLA
subroutine dpotf2(UPLO, N, A, LDA, INFO)
DPOTF2 computes the Cholesky factorization of a symmetric/Hermitian positive definite matrix (unblock...