136 parameter( one = 1.0e+0, zero = 0.0e+0 )
159 upper = lsame( uplo,
'U' )
160 IF( .NOT.upper .AND. .NOT.lsame( uplo,
'L' ) )
THEN
162 ELSE IF( n.LT.0 )
THEN
166 CALL xerbla(
'SPPTRF', -info )
187 $
CALL stpsv(
'Upper',
'Transpose',
'Non-unit', j-1, ap,
192 ajj = ap( jj ) - sdot( j-1, ap( jc ), 1, ap( jc ), 1 )
193 IF( ajj.LE.zero )
THEN
197 ap( jj ) = sqrt( ajj )
209 IF( ajj.LE.zero )
THEN
220 CALL sscal( n-j, one / ajj, ap( jj+1 ), 1 )
221 CALL sspr(
'Lower', n-j, -one, ap( jj+1 ), 1,
subroutine xerbla(SRNAME, INFO)
XERBLA
subroutine spptrf(UPLO, N, AP, INFO)
SPPTRF
subroutine sscal(N, SA, SX, INCX)
SSCAL
subroutine sspr(UPLO, N, ALPHA, X, INCX, AP)
SSPR
subroutine stpsv(UPLO, TRANS, DIAG, N, AP, X, INCX)
STPSV