THESE/codes/graphe/Ncut_9/compute_relation.m

   1 function [W,distances] = compute_relation(data,scale_sig,order)
   2 %
   3 %      [W,distances] = compute_relation(data,scale_sig)
   4 %       Input: data= Feature_dimension x Num_data
   5 %       ouput: W = pair-wise data similarity matrix
   6 %              Dist = pair-wise Euclidean distance
   7 %
   8 %
   9 % Jianbo Shi, 1997
  10
  11
  12 distances = zeros(length(data),length(data));
  13 for j = 1:length(data),
  14   distances(j,:) = (sqrt((data(1,:)-data(1,j)).^2 +...
  15                 (data(2,:)-data(2,j)).^2));
  16 end
  17
  18 % distances = X2distances(data');
  19
  20 if (~exist('scale_sig')),
  21     scale_sig = 0.05*max(distances(:));
  22 end
  23
  24 if (~exist('order')),
  25   order = 2;
  26 end
  27
  28 tmp = (distances/scale_sig).^order;
  29
  30 W = exp(-tmp);
  31