MutualInformationWeightMatric( LGObj )

function    MI_Matric = MutualInformationWeightMatric( LGObj )
% This function builds a matric that measures the weight( Ip(Ci, Cj) ) between node i and
% node j. It is used in maximizing the weighted spanning tree for class
% subgraph in the third step.

%Input: OriginData is the Original sample, Dim is the value range of classes.
%Output: CIW_Matric is the class information weight matric. 
  LG = struct(LGObj);
  Dim = LG.VarNumber;
  MI_Matric = zeros( Dim );
      for r = 1 : (Dim-1)
           for c = (r+1) : Dim      %IW_Matric is symmetric
                MI_Matric( r,c ) = ConditionallyIndependent_MutualInformation( LGObj,r ,c  );
                MI_Matric( c,r ) = MI_Matric( r,c ); 
             %  since all information is already in upper triangular.
           end
      end
end