


Function to compute the distance between two ranking vectors, as detailed in Lampel and Moran, 2005 (in Information Retrieval, 8, 245-264). INPUT : two ranking vectors of the same size OUTPUT: their distance _______________________________________________________________________ Copyright (C) 2011 Machine Learning & Neuroimaging Laboratory


0001 function dr=prt_comp_ranking_dist(v,w) 0002 % Function to compute the distance between two ranking vectors, as detailed 0003 % in Lampel and Moran, 2005 (in Information Retrieval, 8, 245-264). 0004 % 0005 % INPUT : two ranking vectors of the same size 0006 % OUTPUT: their distance 0007 %_______________________________________________________________________ 0008 % Copyright (C) 2011 Machine Learning & Neuroimaging Laboratory 0009 0010 % Written by Jessica Schrouff, 18/10/2012 0011 0012 if nargin<2 0013 error('prt_comp_ranking_dist:nargin',... 0014 'two ranking vectors should be entered, please correct') 0015 end 0016 nr=length(v); 0017 0018 if nr~=length(w) 0019 error('prt_comp_ranking_dist:sizeerror',... 0020 'the ranking vectors do not have the same size, please correct') 0021 end 0022 0023 % Compute the distance 0024 dr=0; 0025 for i=1:nr 0026 for j=1:nr 0027 if (v(i)<v(j) && w(i)>w(j)) 0028 tmp=1; 0029 else 0030 tmp=0; 0031 end 0032 dr=dr+tmp; 0033 end 0034 end 0035 dr=2*dr/(nr*(nr-1)); 0036 0037 end