function [bestelemwise,bestseqwise] = choosebestscore(scores,starts,tiebreaker)

% CHOOSEBESTSCORE : chooses bestseqwise score 
%
% [bestelemwise,bestseqwise] = choosebestseqwisescore(scores,starts,tiebreaker)
%
% Suppose there are K sequences with a total of N elements
%  The N elements have scores (from some previous classifier) in scores
%  The elements of the k-th sequence are in 
%      starts(k):starts(k+1)-1, if k == 1 to K-1
%   or starts(K):N              if k == K
%
% scores is a N-element vector of scores
% starts is a K-element vector of start positions 
%   (it is a monotone increasing subvector of [1:N])
% tiebreaker is one of the strings
%   'first' : in case of ties, choose the first
%   'last' : in case of ties, choose the last
%   'rand' : in case of ties, choose something randomly
%
% bestseqwise is a K x 1 vector whose k-th element a=bestseqwise(k) is between 1 and n inclusive
%  (where n is the length of the k-th sequence) and a-th score in that k-th sequence is highest
%
% bestelemewise is a N x 1 binary vector whose n-th element is 1 if the n-th element had the 
%  highest score in its sequence
%
% Example:
%
%  scores = [1.1   0.5   1.1   0.2   -0.4]
%  starts = [1 4]
%  tiebreaker = 'last'
%
%  This example has two sequences, 
%    the first sequence has scores [1.1  0.5  1.1] and
%    the second sequence has scores [0.2  -0.4]
%
%  The output is
% 
%  bestseqwise = [3 1]
%  bestelemwise = [0 0 1 1 0]

if (size(starts,1)==1),starts=starts';end   % now is col vector
K = length(starts);
N = length(scores);

starts(K+1)=N+1;
bestseqwise=zeros(K,1);

for k=1:K
  a = starts(k);
  b = starts(k+1)-1;

  x = scores(a:b);
  f = find(x == max(x));
  if (length(f)==1)
    bestseqwise(k)=f;
  else
    if strcmp(tiebreaker ,'first')
      bestseqwise(k)=f(1);
    elseif strcmp(tiebreaker ,'last')
      bestseqwise(k)=f(end);
    elseif strcmp(tiebreaker ,'rand')
      bestseqwise(k) = max(1,ceil(rand*length(f)));
    else
      error(sprintf('unknown tiebreaker %s',tiebreaker));
    end
  end
end

bestelemwise = zeros(N,1);
bestelemwise(starts(1:K)-1+bestseqwise)=1;