wolffd@0: function graph_to_dot(G, varargin)
wolffd@0: % DAG_TO_DOT Make a file representing the directed graph in dotty format.
wolffd@0: % dag_to_dot(G, ...)
wolffd@0: %
wolffd@0: % Optional arguments should be passed as name/value pairs [default]
wolffd@0: %
wolffd@0: % 'filename' - if omitted, we write to 'tmp.dot', convert this to 'tmp.ps',
wolffd@0: %              and then call ghostview automatically 
wolffd@0: % 'arc_label' - arc_label{i,j} is a string attached to the i->j arc. [""]
wolffd@0: % 'node_label' - node_label{i} is a string attached to node i. ["i"]
wolffd@0: % 'width'      - width in inches [10]
wolffd@0: % 'height'     - height in inches [10]
wolffd@0: % 'leftright'  - 1 means layout left-to-right, 0 means top-to-bottom [0]
wolffd@0: % 'directed'  - 1 means use directed arcs, 0 means undirected [1]
wolffd@0: %
wolffd@0: % For details on dotty, See http://www.research.att.com/sw/tools/graphviz
wolffd@0: %
wolffd@0: % Example:
wolffd@0: % G = rand(5,5);
wolffd@0: % names = cell(5,5);
wolffd@0: % names{1,2} = 'arc 1-2';
wolffd@0: % graph_to_dot(G, 'arc_label', names)
wolffd@0: % or graph_to_dot(G, 'arc_label', 'numbers') % prints value of G(i,j) on i->j arc 
wolffd@0: 
wolffd@0: % Kevin Murphy, 1998
wolffd@0: 
wolffd@0: % set default args
wolffd@0: filename = [];
wolffd@0: node_label = [];
wolffd@0: arc_label = [];
wolffd@0: width = 10;
wolffd@0: height = 10;
wolffd@0: leftright = 0;
wolffd@0: directed = 1;
wolffd@0: % get optional args
wolffd@0: args = varargin;
wolffd@0: for i=1:2:length(args)
wolffd@0:   switch args{i}
wolffd@0:    case 'filename', filename = args{i+1};
wolffd@0:    case 'node_label', node_label = args{i+1};
wolffd@0:    case 'arc_label', arc_label = args{i+1};
wolffd@0:    case 'width', width = args{i+1};
wolffd@0:    case 'height', height = args{i+1};
wolffd@0:    case 'leftright', leftright = args{i+1};
wolffd@0:    case 'directed', directed = args{i+1};
wolffd@0:   end
wolffd@0: end
wolffd@0: 
wolffd@0: if isstr(arc_label) & strcmp(arc_label, 'numbers')
wolffd@0:   N = length(G);
wolffd@0:   arc_label = cell(N,N);
wolffd@0:   for i=1:N
wolffd@0:     for j=1:N
wolffd@0:       arc_label{i,j} = sprintf('%4.2f', G(i,j));
wolffd@0:     end
wolffd@0:   end
wolffd@0: end
wolffd@0: 
wolffd@0: if isempty(filename)
wolffd@0:   make_file(G, 'tmp.dot', node_label, arc_label, width, height, leftright, directed);
wolffd@0:   if isunix
wolffd@0:     !dot -Tps tmp.dot -o tmp.ps
wolffd@0: 
wolffd@0:     !gs tmp.ps &
wolffd@0:   else
wolffd@0:     dos('dot -Tps tmp.dot -o tmp.ps');
wolffd@0:     dos('gsview32 tmp.ps &');
wolffd@0:   end
wolffd@0: else
wolffd@0:   
wolffd@0:   
wolffd@0:   make_file(G, filename, node_label, arc_label, width, height, leftright, directed);
wolffd@0: end
wolffd@0: 
wolffd@0: 
wolffd@0: %%%%%%
wolffd@0: 
wolffd@0: function make_file(G, filename, node_label, arc_label, width, height, leftright, directed)
wolffd@0: 
wolffd@0: n = length(G);
wolffd@0: fid = fopen(filename, 'w');
wolffd@0: if directed
wolffd@0:   fprintf(fid, 'digraph G {\n');
wolffd@0: else
wolffd@0:   fprintf(fid, 'graph G {\n');
wolffd@0: end
wolffd@0: fprintf(fid, 'center = 1;\n');
wolffd@0: fprintf(fid, 'size=\"%d,%d\";\n', width, height);
wolffd@0: if leftright
wolffd@0:   fprintf(fid, 'rankdir=LR;\n');
wolffd@0: end
wolffd@0: for i=1:n
wolffd@0:   if isempty(node_label)
wolffd@0:     fprintf(fid, '%d;\n', i);
wolffd@0:   else
wolffd@0:     fprintf(fid, '%d [ label = "%s" ];\n', i, node_label{i});
wolffd@0:   end
wolffd@0: end
wolffd@0: if directed
wolffd@0:   for i=1:n
wolffd@0:     cs = children(G,i);
wolffd@0:     for j=1:length(cs)
wolffd@0:       c = cs(j);
wolffd@0:       if isempty(arc_label)
wolffd@0: 	fprintf(fid, '%d -> %d;\n', i, c);
wolffd@0:       else
wolffd@0: 	fprintf(fid, '%d -> %d [label="%s"];\n', i, c, arc_label{i,c});
wolffd@0:       end
wolffd@0:     end
wolffd@0:   end
wolffd@0: else
wolffd@0:   for i=1:n
wolffd@0:     ns = intersect(neighbors(G,i), i+1:n); % remove duplicate arcs
wolffd@0:     for j=1:length(ns)
wolffd@0:       c = ns(j);
wolffd@0:       if isempty(arc_label)
wolffd@0: 	fprintf(fid, '%d -- %d [dir=none];\n', i, c);
wolffd@0:       else
wolffd@0: 	fprintf(fid, '%d -- %d [label="%s",dir=none];\n', i, c, arc_label{i,c});
wolffd@0:       end
wolffd@0:     end
wolffd@0:   end
wolffd@0: end
wolffd@0: fprintf(fid, '\n}');
wolffd@0: fclose(fid);
wolffd@0: 
wolffd@0: 
wolffd@0: 
wolffd@0: %%%%%%%%%%%%%%%
wolffd@0: 
wolffd@0: function cs = children(adj_mat, i, t)
wolffd@0: % CHILDREN Return the indices of a node's children in sorted order
wolffd@0: % c = children(adj_mat, i, t)
wolffd@0: %
wolffd@0: % t is an optional argument: if present, dag is assumed to be a 2-slice DBN
wolffd@0: 
wolffd@0: if nargin < 3 
wolffd@0:   cs = find(adj_mat(i,:));
wolffd@0: else
wolffd@0:   if t==1
wolffd@0:     cs = find(adj_mat(i,:));
wolffd@0:   else
wolffd@0:     ss = length(adj_mat)/2;
wolffd@0:     j = i+ss;
wolffd@0:     cs = find(adj_mat(j,:)) + (t-2)*ss;
wolffd@0:   end
wolffd@0: end
wolffd@0: 
wolffd@0: %%%%%%%%%%%%
wolffd@0: 
wolffd@0: function ps = parents(adj_mat, i)
wolffd@0: % PARENTS Return the list of parents of node i
wolffd@0: % ps = parents(adj_mat, i)
wolffd@0: 
wolffd@0: ps = find(adj_mat(:,i))';
wolffd@0: 
wolffd@0: %%%%%%%%%%%%%
wolffd@0: 
wolffd@0: function ns = neighbors(adj_mat, i)
wolffd@0: % NEIGHBORS Find the parents and children of a node in a graph.
wolffd@0: % ns = neighbors(adj_mat, i)
wolffd@0: 
wolffd@0: ns = union(children(adj_mat, i), parents(adj_mat, i));
wolffd@0: 
wolffd@0: 
wolffd@0: