

   WWeeiigghhtt ddiiaaggrraammss aanndd tthhee hhaatt mmaattrriixx ffoorr aa llooccaall rreeggrreessssiioonn
   mmooddeell..

        hatmatrix(formula, ...)

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

    formula: model formula.

        ...: Other arguments to `locfit' and `locfit.raw'.

   DDeessccrriippttiioonn::

        `hatmatrix()' computes the weight diagrams (also known
        as equivalent or effective kernels) for a local regres-
        sion smooth.  Essentially, `hatmatrix()' is a front-end
        to `locfit()', setting a flag to compute and return
        weight diagrams, rather than the fit.

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

        A matrix with n rows and p columns; each column being
        the weight diagram for the corresponding `locfit' fit
        point.  If `ev="data"', this is the transpose of the
        hat matrix.

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

        `locfit', `plot.locfit.1d', `plot.locfit.2d',
        `plot.locfit.3d', `lines.locfit', `predict.locfit'

