function [common,s] =  identify( path, s)
% [common,s] =  identify(dir,name1, name2, num)
% dir : directory to find necessary files in
% name1 : name of first file, bw image of centers
% name2 : name of second file, ascii format connections data
% num : image number
% common : structure of tile signatures (neighborhoods determined by
% connections)
% s : size of neighborhood used
%
% find and record neighborhoods of each tile
% method:
% record existance or absense of all paths from a node length [2,3]. [4,6] directions 

load( '-mat', path, 'conn','N', 'x','y','rotim')
image = rotim;

conn2 = conn(:,[2,3,5,6]);

% method for choosing s?
if nargin < 2
    if N < 100
        s = 16;
    elseif N < 1000
        s = 36;
    elseif N < 10000
        s = 64;
    else 
        s = 216;
    end 
end
common = struct( 'ID', zeros(s,0), 'count', [], 'n', [] , 'length', 0);

for n = 1:N
    % determine neighborhood for node n
    tempID = zeros(s,1);
    switch s                            % improve more?
        case 16
            for s1 = 1:4
            for s2 = 1:4
                n2 = conn2(n,s1);
                if n2 ~= 0
                if conn2(n2,s2) ~= 0
                    tempID(4*(s1-1)+s2) = 1;
                end
                end
            end
            end  
            
        case 36
            for s1 = 1:6
            for s2 = 1:6
                n2 = conn(n,s1);
                if n2 ~= 0
                if conn(n2,s2) ~= 0
                    tempID(6*(s1-1)+s2) = 1;
                end
                end
            end
            end
            
        case 64
            for s1 = 1:4
            for s2 = 1:4
            for s3 = 1:4
                n2 = conn2(n,s1);
                if n2 ~= 0
                n3 = conn2(n2,s2);
                if n3 ~= 0
                if conn2(n3,s3) ~= 0
                    tempID(16*(s1-1)+4*(s2-1)+s3) = 1;
                end
                end
                end
            end
            end
            end
           
        case 216
            for s1 = 1:6
            for s2 = 1:6
            for s3 = 1:6
                n2 = conn(n,s1);
                if n2 ~= 0 
                n3 = conn(n2,s2);
                if n3 ~= 0 
                if conn(n3,s3) ~= 0
                    tempID(36*(s1-1)+6*(s2-1)+s3) = 1;
                end
                end
                end
            end
            end
            end
    end
    
    %%--------------------%%-----------------%%---------------------%%
    
    % determine where to put this node.
    if common.length == 0
        % add to list, bc list is empty
        common.ID = [common.ID, tempID];
        common.count = [common.count, 1];
        common.n = [common.n, n];
        common.length = common.length + 1;
    else
        % repeat current ID until is same size as common
        temp = repmat(tempID, [1, common.length]);
        % compare current ID to each ID in common list
        temp = xor( temp, common.ID );
        % sum up the results of each comparison
        % if sums to zero, perfect match
        temp = sum( temp );
        % gives column of perfect match if it exists, empty otherwise
        temp = find ( temp == 0 );
        % if a match exists, increase count
        if ~isempty( temp )
            common.count(temp) = common.count(temp) + 1;
        else 
            % add to list if matach doesnt exist
            common.ID = [common.ID, tempID];
            common.count = [common.count, 1];
            common.n = [common.n, n];
            common.length = common.length + 1;
        end
    end
    
end

    imagesc(image)
    plotconn(x,y,conn,N)
    hold on
    
% plot locations of unique signatures in red
for n = 1:common.length
    if common.count(n) == 1
        a = common.n(n);
        plot ( x(a), y(a), 'ro');
        
    end
end
    
    hold off