126 SUBROUTINE ctbt06( RCOND, RCONDC, UPLO, DIAG, N, KD, AB, LDAB,
137 REAL rat, rcond, rcondc
141 COMPLEX ab( ldab, * )
148 parameter( zero = 0.0e+0, one = 1.0e+0 )
151 REAL anorm, bignum, eps, rmax, rmin
163 rmax = max( rcond, rcondc )
164 rmin = min( rcond, rcondc )
168 IF( rmin.LT.zero )
THEN
174 ELSE IF( rmin.GT.zero )
THEN
178 rat = rmax / rmin - one
180 ELSE IF( rmax.EQ.zero )
THEN
194 bignum = one /
slamch(
'Safe minimum' )
195 anorm =
clantb(
'M', uplo, diag, n, kd, ab, ldab, rwork )
197 rat = rmax*( min( bignum / max( one, anorm ), one / eps ) )
real function clantb(NORM, UPLO, DIAG, N, K, AB, LDAB, WORK)
CLANTB returns the value of the 1-norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a triangular band matrix.
subroutine ctbt06(RCOND, RCONDC, UPLO, DIAG, N, KD, AB, LDAB, RWORK, RAT)
CTBT06
real function slamch(CMACH)
SLAMCH