The class "pp" represents discrete measures with some fixed mass at any of finitely many locations.
Dominic Schuhmacher dschuhm1@uni-goettingen.de
Objects of class "pp" may be created by the function 
  pp, and are most commonly used as input to the function
  transport. There are methods plot, print and
  summary for this class.
An object of class "pp" contains the following elements:
dimension | the dimension of the Euclidean space in which the patterns live. Must be \(\geq 2\). | 
N | the total number of points. | 
coordinates | the coordinates of the points. An N \(\times\) dimension matrix, where each row
    corresponds to a point. | 
Constructor function pp.