LINPACK reciprocal condition estimator.
RCOND(X) is an estimate for the reciprocal of the
condition of X in the 1-norm obtained by the LINPACK
condition estimator. If X is well conditioned, RCOND(X)
is near 1.0. If X is badly conditioned, RCOND(X) is
See also COND15XZCU2, NORM , CONDEST , NORMEST .