function ENCODEDVECTOR = prefix_encode(CODE,DATAVECTOR);
% prefix_encode: encode data using given code book.
%
% Usage:
%	CODE = [ ...
%		bitstring_to_index([1]),...
%		bitstring_to_index([0,1]),...
%		bitstring_to_index([0,0,1]),...
%		bitstring_to_index([0,0,0]) ];
%	DATAVECTOR = [ 0 1 2 3 0 0 0 0 ];
%	ENCODEDVECTOR = prefix_encode(CODE,DATAVECTOR)'
%	print_without_spaces(ENCODEDVECTOR);
% returns
%		1010010001111
%
%DATAVECTOR has alphabet {0,1,...,k-1} for 
%some integer k
%CODE is a vector of length k giving the
%indices of the codewords for 0,1,...,k-1
%respectively (usually generated by compactcodeP ).
%ENCODEDVECTOR is the encoder output when
%DATAVECTOR is memorylessly encoded by CODE.
%
% See also HUFFMAN_COMPRESS, COMPACTCODEP, CONCAT,
% PREFIX_DECODE.


% documented in
% ftp://oz.ee.umn.edu/users/kieffer/seminar/notes2.ps
% Change log:
% 1999-07-01:DAV: This was very slow for large images, so I sped it up.
%   Now it's much faster.
% 1999-05-06more documentation by David Cary 
% 1999-05-06:DAV: David Cary added more documentation
% ???:JCK: originally by John C. Kieffer
%   http://www.ee.umn.edu/users/kieffer/programs.html


n=length(DATAVECTOR);
i=1:n;
u(i) = CODE(DATAVECTOR(i)+1);
ENCODEDVECTOR=concat(u);

if(0)
   % working original program.
   n=length(DATAVECTOR);
   for i=1:n;
      u(i)=CODE(DATAVECTOR(i)+1);
   end
   ENCODEDVECTOR=concat(u);
end;

% end prefix_encode.m