a character vector, which specifies the type of bounded influence
estimator. If
method="sch", the Schweppe-type or Krasker-Welsch type
bounded influence estimator is used; if
method="mal", the Mallows-type
bounded influence estimator is used.
tuning.p
a scalar which gives the value of the tuning constant for the
psi-function of the corresponding generalized M-estimator. It is
only used if
method="mal".
nx
the number of explanatory variables used in the regression, not including
the intercept.
intercept
logical flag: if
TRUE, an intercept will be fitted by the regression.
sigmax
a scalar which gives the standard deviation of the model matrix
x.
VALUE:
the tuning constant of the optimal weight function which will have
the required asymptotic efficiency.