109 SUBROUTINE dget03( N, A, LDA, AINV, LDAINV, WORK, LDWORK, RWORK,
118 INTEGER lda, ldainv, ldwork, n
119 DOUBLE PRECISION rcond, resid
122 DOUBLE PRECISION a( lda, * ), ainv( ldainv, * ), rwork( * ),
129 DOUBLE PRECISION zero, one
130 parameter( zero = 0.0d+0, one = 1.0d+0 )
134 DOUBLE PRECISION ainvnm, anorm, eps
159 anorm =
dlange(
'1', n, n, a, lda, rwork )
160 ainvnm =
dlange(
'1', n, n, ainv, ldainv, rwork )
161 IF( anorm.LE.zero .OR. ainvnm.LE.zero )
THEN
166 rcond = ( one / anorm ) / ainvnm
170 CALL
dgemm(
'No transpose',
'No transpose', n, n, n, -one, ainv,
171 $ ldainv, a, lda, zero, work, ldwork )
173 work( i, i ) = one + work( i, i )
178 resid =
dlange(
'1', n, n, work, ldwork, rwork )
180 resid = ( ( resid*rcond ) / eps ) / dble( n )
subroutine dgemm(TRANSA, TRANSB, M, N, K, ALPHA, A, LDA, B, LDB, BETA, C, LDC)
DGEMM
double precision function dlange(NORM, M, N, A, LDA, WORK)
DLANGE returns the value of the 1-norm, Frobenius norm, infinity-norm, or the largest absolute value ...
double precision function dlamch(CMACH)
DLAMCH
subroutine dget03(N, A, LDA, AINV, LDAINV, WORK, LDWORK, RWORK, RCOND, RESID)
DGET03