SaveFunctionStructure

 SaveFunctionStructure(filename,NumberVar,ListFactors,Card)

 SaveFunctionStructure:   Saves the structure of a function in the form of a factor graph 
                       The factor graph has two classes of nodes variable
                       nodes and factor nodes. Each variable node should
                       be associated to at least one factor node and
                       viceversa. There each one edge from each variable
                       node to the factor it belongs to.
 INPUTS
 filename:  Name of file 
 NumberVar: Number of variables
 ListFactors: Each  cell {i} stores the numb variables in the factor (k+1), the
              current variable (i), and its k neighbors
 Card: Cardinality of the variables
 OUTPUTS
 file of name 'filename' with the following format:

    Total number of nodes
    Total number of variable  nodes
    for i=1 to Total number of variables nodes
      Variable node (for C compatibility i-1 instead of i is printed to the file) 
      Cardinality of variable node i
    end
    Number of edges in the factor graph
    for i=1 to Total number of edges
      variable node incident to  edge i
      factor node incident to  edge i
    end

 Last version 8/26/2008. Alex Mendiburu and Roberto Santana (roberto.santana@ehu.es)

0001 function SaveFunctionStructure(filename,NumberVar,ListFactors,Card)
0002 % SaveFunctionStructure(filename,NumberVar,ListFactors,Card)
0003 %
0004 % SaveFunctionStructure:   Saves the structure of a function in the form of a factor graph
0005 %                       The factor graph has two classes of nodes variable
0006 %                       nodes and factor nodes. Each variable node should
0007 %                       be associated to at least one factor node and
0008 %                       viceversa. There each one edge from each variable
0009 %                       node to the factor it belongs to.
0010 % INPUTS
0011 % filename:  Name of file
0012 % NumberVar: Number of variables
0013 % ListFactors: Each  cell {i} stores the numb variables in the factor (k+1), the
0014 %              current variable (i), and its k neighbors
0015 % Card: Cardinality of the variables
0016 % OUTPUTS
0017 % file of name 'filename' with the following format:
0018 %
0019 %    Total number of nodes
0020 %    Total number of variable  nodes
0021 %    for i=1 to Total number of variables nodes
0022 %      Variable node (for C compatibility i-1 instead of i is printed to the file)
0023 %      Cardinality of variable node i
0024 %    end
0025 %    Number of edges in the factor graph
0026 %    for i=1 to Total number of edges
0027 %      variable node incident to  edge i
0028 %      factor node incident to  edge i
0029 %    end
0030 %
0031 % Last version 8/26/2008. Alex Mendiburu and Roberto Santana (roberto.santana@ehu.es)
0032 
0033 
0034 totfactors = size(ListFactors,2);
0035 totnodes = totfactors + NumberVar;
0036 
0037 membership = zeros(1,NumberVar); % In how many factors is each variable
0038 
0039 for i=1:totfactors,     
0040   sizefactor = size(ListFactors{i},2);    % Size of factor i
0041   for j=1:sizefactor,
0042      membership(ListFactors{i}(j)) = membership(ListFactors{i}(j)) + 1;
0043   end, 
0044 end,
0045 NumberEdges = sum(membership);
0046 
0047 fid = fopen(filename,'wt');
0048  
0049 fprintf(fid,'%d \n',totnodes);  % Total number of nodes
0050 fprintf(fid,'%d \n',NumberVar); % Total number of variable  nodes
0051   
0052  for i=1:NumberVar,              % Each variable node and its cardinality
0053    fprintf(fid,'%d  \n',i-1);    
0054    fprintf(fid,'%d  \n', Card(i));
0055  end,
0056 
0057 fprintf(fid,'%d \n',NumberEdges); % Number of edges in the factor graph
0058 
0059 for i=1:totfactors,      % All the edges are printed
0060   sizefactor = size(ListFactors{i},2); 
0061   for j=1:sizefactor,
0062   fprintf(fid,'%d  \n',ListFactors{i}(j)-1);
0063   fprintf(fid,'%d  \n',NumberVar+i-1);
0064   end, 
0065 end,
0066 
0067 fclose(fid);
0068