

   PPooiinntt OObbjjeecctt

        point(data.frame, x='x', y='y')

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

   data.frame: a data frame containing the x and y coordinates
             for each point and the variables observed at each
             point

          x: the name of the column in data.frame that contains
             the x coordinate

          y: the name of the column in data.frame that contains
             the y coordinate

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

        Create an object of class point from a data frame.

        An object of class point represents the observed data
        of a spatial process. This includes the spatial loca
        tion of sampling sites and the values observed at those
        sites. A point object is stored as a data frame. The
        data frame must contain one column for the X coordinate
        and one column for the Y coordinate of each point, as
        well as any number of columns representing data
        observed at the points.

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

        A point object:

          x: vector of x coordinates

          y: vector of ycoordinates

       var1: vector of the first variable

        ...: ...

       varm: vector of the mth variable

   RReeffeerreenncceess::

        http://www.gis.iastate.edu/SGeoStat/homepage.html

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

        `point'

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

        data(maas)
        maas.pts <- point(maas)

