

   NNoorrmmaall kkeerrnneell rreeggrreessssiioonn eessttiimmaattee

        nkreg(data.x, data.y, bandwidth, n.points, grid)

   AArrgguummeennttss::

     data.x: Vector or matrix of independent variables.

     data.y: Vector of the dependent variable

   bandwidth: Vector of bandwidths

   n.points: Number of equally spaced points to evaluate a uni-
             variate density estimate.

       grid: A vector or matrix of values to evaluate the esti-
             mate.The defautl is to use the data.

   VVaalluuee::

        A list where x is the points used for evaluation, y the
        density estimates at these points and bandwidths and h
        the vector of bandwidths. If more than one bandwidth is
        given then the estimates are arranged as columns in the
        matrix y.

   SSeeee AAllssoo::

        nkden, nkden.cv, ksmooth

   EExxaammpplleess::

        nkreg( auto.paint$thick, auto.paint$DOI, 5.0)-> look
        plot( auto.paint$thick, auto.paint$DOI)
        lines( look$x, look$y)
        plot( look$y, auto.paint$DOI- look$y, xlab="Predicted", ylab="Residuals")

