INTERFACE VarKamSpring;

IMPORT Energy;

TYPE
  T <: Public;
  Public = Energy.T OBJECT
      length: REAL;   (* Ideal edge length for. *)
      strength: REAL; (* Edge strength factor. *)
    METHODS
      init(): T;
    END;
  (*
    In Kamada's energy, a spring is placed between every pair of
    triangulation vertices u, v, adjacent or not, whose length is
    equal to the graph-theoretical distance between u and v in T.
    
    In this version, the distances are computed by setting each edge's
    length to "length * sqrt (Na/Nb + Nb/Na)" where "Na" and "Nb" are
    the endpoint degrees.
  *)
  
END VarKamSpring.
(* Last edited on 2001-05-21 02:35:52 by stolfi *)