1 SUBROUTINE dget02( TRANS, M, N, NRHS, A, LDA, X, LDX, B, LDB,
10 INTEGER lda, ldb, ldx, m, n, nrhs
11 DOUBLE PRECISION resid
14 DOUBLE PRECISION a( lda, * ), b( ldb, * ), rwork( * ),
77 DOUBLE PRECISION zero, one
78 parameter( zero = 0.0d+0, one = 1.0d+0 )
82 DOUBLE PRECISION anorm, bnorm, rhsnorm, eps, xnorm
86 DOUBLE PRECISION dasum, dlamch, dlange
87 EXTERNAL lsame, dasum, dlamch, dlange
99 IF( m.LE.0 .OR. n.LE.0 .OR. nrhs.EQ.0 )
THEN
104 IF( lsame(
trans,
'T' ) .OR. lsame(
trans,
'C' ) )
THEN
114 eps = dlamch(
'Epsilon' )
115 anorm = dlange(
'1', n1, n2, a, lda, rwork )
116 rhsnorm = dlange(
'1', n1, nrhs, b, ldb, rwork )
117 IF( anorm.LE.zero )
THEN
124 CALL dgemm(
trans,
'No transpose', n1, nrhs, n2, -one, a, lda, x,
132 bnorm = dasum( n1, b( 1, j ), 1 )
133 xnorm = dasum( n2, x( 1, j ), 1 )
134 IF( xnorm.LE.zero )
THEN
137 resid =
max( resid, ( bnorm) / ((anorm * xnorm + rhsnorm)*