sample multiset implementation

NCDM.m

+% /******************************************************************************
+% 
+% This program, "NCDM", the associated MATLAB scripts and all 
+% provided data, are copyright (C) 2018 Andrew R. Cohen, All rights reserved.
+% 
+% This program uses bzip2 compressor as a static library.
+% A built version for windows 64 is included. for other platforms, see 
+% the files in the bzlib project on https://git-bioimage.coe.drexel.edu
+% 
+% This software may be referenced as:
+% A.R.Cohen and P.M.B. Vitanyi, Normalized Compression Distance of Multisets
+%       with Applications, IEEE Transactions on Pattern Analysis and Machine 
+%       Intelligence. 2015 Aug;37(8):1602-14, 
+%
+% Redistribution and use in source and binary forms, with or without
+% modification, are permitted provided that the following conditions
+% are met:
+% 
+% 1. Redistributions of source code must retain the above copyright
+%    notice, this list of conditions and the following disclaimer.
+% 
+% 2. The origin of this software must not be misrepresented; you must 
+%    not claim that you wrote the original software.  If you use this 
+%    software in a product, an acknowledgment in the product 
+%    documentation would be appreciated but is not required.
+% 
+% 3. Altered source versions must be plainly marked as such, and must
+%    not be misrepresented as being the original software.
+% 
+% 4. The name of the author may not be used to endorse or promote 
+%    products derived from this software without specific prior written 
+%    permission.
+% 
+% THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
+% OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+% WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+% ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+% DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+% DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+% GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+% INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+% WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+% NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+% SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+% 
+% Andrew R. Cohen andrew.r.cohen@drexel.edu
+% 
+% ******************************************************************************/
+
+% NCDM
+% Returns the normalized compression distance for the multiset X
+% each row of x is assumed to be a single member x of set X
+% this is the multiset NCD
+
+function ncd = NCD(X)
+
+if size(X,1)<2
+    ncd=0;
+    fprintf(1,'single element x of X : d=0\n');
+    return
+end
+GX = Press(X',[]);
+cxi=[];
+for i=1:size(X,1)
+    xi=X(i,:);
+    cxi(i)=Press(xi,[]);
+end
+gx = min([cxi]);
+
+gExclude =[];
+xExclude=[];
+for i=1:size(X,1)
+    xExclude=X;
+    xExclude(i,:)=[];
+    gExclude(i)=Press(xExclude',[]); % G(X\x)
+end
+
+ncd = (GX - gx)/(max(gExclude));
+
+
+
+end
+
+