123 SUBROUTINE zspt02( UPLO, N, NRHS, A, X, LDX, B, LDB, RWORK,
133 INTEGER LDB, LDX, N, NRHS
134 DOUBLE PRECISION RESID
137 DOUBLE PRECISION RWORK( * )
138 COMPLEX*16 A( * ), B( ldb, * ), X( ldx, * )
144 DOUBLE PRECISION ZERO, ONE
145 parameter ( zero = 0.0d+0, one = 1.0d+0 )
147 parameter ( cone = ( 1.0d+0, 0.0d+0 ) )
151 DOUBLE PRECISION ANORM, BNORM, EPS, XNORM
154 DOUBLE PRECISION DLAMCH, DZASUM, ZLANSP
155 EXTERNAL dlamch, dzasum, zlansp
167 IF( n.LE.0 .OR. nrhs.LE.0 )
THEN
174 eps = dlamch(
'Epsilon' )
175 anorm = zlansp(
'1', uplo, n, a, rwork )
176 IF( anorm.LE.zero )
THEN
184 CALL zspmv( uplo, n, -cone, a, x( 1, j ), 1, cone, b( 1, j ),
193 bnorm = dzasum( n, b( 1, j ), 1 )
194 xnorm = dzasum( n, x( 1, j ), 1 )
195 IF( xnorm.LE.zero )
THEN
198 resid = max( resid, ( ( bnorm / anorm ) / xnorm ) / eps )
subroutine zspt02(UPLO, N, NRHS, A, X, LDX, B, LDB, RWORK, RESID)
ZSPT02
subroutine zspmv(UPLO, N, ALPHA, AP, X, INCX, BETA, Y, INCY)
ZSPMV computes a matrix-vector product for complex vectors using a complex symmetric packed matrix ...