139 parameter( one = 1.0e+0, zero = 0.0e+0 )
162 upper = lsame( uplo,
'U' )
163 IF( .NOT.upper .AND. .NOT.lsame( uplo,
'L' ) )
THEN
165 ELSE IF( n.LT.0 )
THEN
169 CALL
xerbla(
'SPPTRF', -info )
190 $ CALL
stpsv(
'Upper',
'Transpose',
'Non-unit', j-1, ap,
195 ajj = ap( jj ) - sdot( j-1, ap( jc ), 1, ap( jc ), 1 )
196 IF( ajj.LE.zero )
THEN
200 ap( jj ) = sqrt( ajj )
212 IF( ajj.LE.zero )
THEN
223 CALL
sscal( n-j, one / ajj, ap( jj+1 ), 1 )
224 CALL
sspr(
'Lower', n-j, -one, ap( jj+1 ), 1,
subroutine xerbla(SRNAME, INFO)
XERBLA
subroutine stpsv(UPLO, TRANS, DIAG, N, AP, X, INCX)
STPSV
subroutine sspr(UPLO, N, ALPHA, X, INCX, AP)
SSPR
subroutine spptrf(UPLO, N, AP, INFO)
SPPTRF
subroutine sscal(N, SA, SX, INCX)
SSCAL