% Macro used for preparing the blog post http://www.37steps.com/4536/eu-song-contest/
% PRTools version 5.1.1 has been used\
%
% Bob Duin, 14 May 2014

% load the data
prdownload('http://37steps.com/data/examples/eu_song_2014.mat');
load eu_song_2014

% extract labels: feature labels are the countries of the songs
% object labels afre the voting countries
flab = getfeatlab(x);
olab = getlabels(x);
% correct for naste underscore
olab(olab=='_') = '-';
x = setlabels(x,olab);

% rank objects by alphabetic label order
[dummy,R] = sortrows(olab);
x = x(R,:);
olab = olab(R,:);

% get rid of existing figures
delfigs

% correct for 0 points of native song
for j=1:size(x,2)
  flabj = flab(j,:);
  n = findlabels(x,flabj);
  x(n,j) = 12;
end
x = x*normm; % normalize vectors to unit legth (L1)

% compute Hellinger distances
d = x*proxm(x,'g');

% PCA scatterplot
figure;
g = x*(pcam*mapex);
scattern(g,0,[0 0 0]);
marksize(1);
text(+g(:,1),+g(:,2),olab,'HorizontalAlignment','center');
fontsize(16)

% MDS scatterplot computed from dissimilarity representation
figure;
g = d*(sammonm*mapex);
scattern(g,0,[0 0 0]);
marksize(1);
text(+g(:,1),+g(:,2),olab,'HorizontalAlignment','center');
fontsize(16)
% manual rotation needed for alignment with pca

% hierarchical clustering
c = hclust(d,'c');
L = c(1,:); % object order

% find 5 neighbors for every object
neighbors = cell(size(d,1),6);
for j=1:size(d,1)
  [dd,R] = sort(+d(j,:));
  fprintf('<tr>')
  for i=1:6
    fprintf('<td>%s</td>',olab(R(i),:))
    neighbors{j,i} = deblank(olab(R(i),:));
  end
  fprintf('</tr>\n');
end

% Order objects according to their total distance to other objects
s = sum(+d);
[ss,R] = sort(s);
ranksum = olab(R,:)
  
% Plot dendrogram
figure;
plotdg(c,[],true);
set(gca,'ytick',[1:37]);
set(gca,'yticklabel',olab(L,:));

% Image from distances, sorted
figure;
J = fliplr(L);
imagesc(+d(J,J));
colormap gray;
set(gca,'ytick',[1:37]);
set(gca,'yticklabel',olab(J,:));
set(gca,'xtick',[]);

% Image from distances unsorted
figure;
imagesc(+d);
colormap gray;
set(gca,'ytick',[1:37]);
set(gca,'yticklabel',olab);
set(gca,'xtick',[]);

showfigs