% AUTORIGHTS
% Copyright (C) 2007 Princeton University
%       
% This file is part of Ferret Toolkit.
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% Ferret Toolkit is free software; you can redistribute it and/or modify
% it under the terms of the GNU General Public License as published by
% the Free Software Foundation; either version 2, or (at your option)
% any later version.
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% but WITHOUT ANY WARRANTY; without even the implied warranty of
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\section{Distance Functions}
New distance functions can be added by toolkit user. Also the
customized distance function (eg: L2 distance using only certain
dimensions from the cass\_vec) can be generated on the fly to satisfy
customized queries.

\subsection{CASS Distance Functions}
\begin{verbatim}
enum cass_vecset_type_t {any_vecset, single_cass_vec, set_of_cass_vecs,
  ...};
enum cass_cass_vec_type_t {any_cass_vec, float_array, L1_sketch,
  multires_sketch, ...};
enum cass_vecset_dist_measure_t {any_vecset_dist, emd,
  one_to_one_best_match, ...};
enum cass_cass_vec_distance_measure_t {any_cass_vec_dist, L1, L2, ...};

float (*cass_cass_vec_dist_func)(cass_cass_vec_t *f1, cass_cass_vec_t *f2);
float (*cass_vecset_dist_func)(cass_vecset_t *f1, cass_vecset_t *f2);

\end{verbatim}