The generic function nobjects counts the number of
geometrical objects in the spatial dataset x.
The methods for point patterns (classes "ppp" and "ppx",
embracing "pp3" and "lpp")
count the number of points in the pattern.
The method for line segment patterns (class "psp")
counts the number of line segments in the pattern.
The method for tessellations (class "tess")
counts the number of tiles of the tessellation.