143 SUBROUTINE dpbtf2( UPLO, N, KD, AB, LDAB, INFO )
152 INTEGER info, kd, ldab, n
155 DOUBLE PRECISION ab( ldab, * )
161 DOUBLE PRECISION one, zero
162 parameter( one = 1.0d+0, zero = 0.0d+0 )
177 INTRINSIC max, min, sqrt
184 upper =
lsame( uplo,
'U' )
185 IF( .NOT.upper .AND. .NOT.
lsame( uplo,
'L' ) )
THEN
187 ELSE IF( n.LT.0 )
THEN
189 ELSE IF( kd.LT.0 )
THEN
191 ELSE IF( ldab.LT.kd+1 )
THEN
195 CALL
xerbla(
'DPBTF2', -info )
204 kld = max( 1, ldab-1 )
225 CALL
dscal( kn, one / ajj, ab( kd,
j+1 ), kld )
226 CALL
dsyr(
'Upper', kn, -one, ab( kd,
j+1 ), kld,
227 $ ab( kd+1,
j+1 ), kld )
249 CALL
dscal( kn, one / ajj, ab( 2,
j ), 1 )
250 CALL
dsyr(
'Lower', kn, -one, ab( 2,
j ), 1,
251 $ ab( 1,
j+1 ), kld )
subroutine dsyr(UPLO, N, ALPHA, X, INCX, A, LDA)
DSYR
subroutine dpbtf2(UPLO, N, KD, AB, LDAB, INFO)
DPBTF2 computes the Cholesky factorization of a symmetric/Hermitian positive definite band matrix (un...
subroutine xerbla(SRNAME, INFO)
XERBLA
logical function lsame(CA, CB)
LSAME
subroutine dscal(N, DA, DX, INCX)
DSCAL
set ue cd $ADTTMP cat<< EOF > tmp f Program LinearEquations Implicit none Real j