comparison toolboxes/FullBNT-1.0.7/KPMstats/histCmpChi2.m @ 0:e9a9cd732c1e tip

first hg version after svn

+function d = histCmpChi2(h1, h2)
+% Compare two histograms using chi-squared
+% function d = histCmpChi2(h1, h2)
+%
+% d(i,j) = chi^2(h1(i,:), h2(j,:)) = sum_b  (h1(i,b)-h2(j,b)^2 / (h1(i,b) + h2(j,b))
+
+[N B] = size(h1);
+d = zeros(N,N);
+for i=1:N
+  h1i = repmat(h1(i,:), N, 1);
+  numer = (h1i - h2).^2;
+  denom = h1i + h2 + eps; % if denom=0, then numer=0
+  d(i,:) = sum(numer ./ denom, 2);
+end
+