1 SUBROUTINE zpot02( UPLO, N, NRHS, A, LDA, X, LDX, B, LDB, RWORK,
10 INTEGER lda, ldb, ldx, n, nrhs
11 DOUBLE PRECISION resid
14 DOUBLE PRECISION rwork( * )
15 COMPLEX*16 a( lda, * ), b( ldb, * ), x( ldx, * )
74 DOUBLE PRECISION zero, one
75 parameter( zero = 0.0d+0, one = 1.0d+0 )
77 parameter( cone = ( 1.0d+0, 0.0d+0 ) )
81 DOUBLE PRECISION anorm, bnorm, eps, xnorm, rhsnorm
84 DOUBLE PRECISION dlamch, dzasum,
zlanhe, clange
85 EXTERNAL dlamch, dzasum,
zlanhe, clange
97 IF( n.LE.0 .OR. nrhs.LE.0 )
THEN
104 eps = dlamch(
'Epsilon' )
106 rhsnorm = clange(
'1', n, nrhs, b, ldb, rwork )
107 IF( anorm.LE.zero )
THEN
114 CALL zhemm(
'Left',
uplo, n, nrhs, -cone, a, lda, x, ldx, cone, b,
122 bnorm = dzasum( n, b( 1, j ), 1 )
123 xnorm = dzasum( n, x( 1, j ), 1 )
124 IF( xnorm.LE.zero )
THEN
127 resid =
max( resid, ( bnorm) / ((anorm * xnorm + rhsnorm)*