comparison toolboxes/graph_visualisation/graphViz4Matlab/layouts/Gvizlayout.m @ 0:e9a9cd732c1e tip

first hg version after svn

+classdef Gvizlayout < Abstractlayout
+% Use the graphVIZ package to determine the optimal layout for a graph.
+%
+% Matthew Dunham
+% University of British Columbia 
+% http://www.cs.ubc.ca/~mdunham/
+   properties
+     xmin;               % The left most point on the graph axis in data units           
+     xmax;               % The right most point on the graph axis in data units
+     ymin;               % The bottom most point on the graph axis in data units
+     ymax;               % The top most point on the graph axis in data units
+     adjMatrix;          % The adjacency matrix
+     maxNodeSize;        % The maximum diameter of a node in data units
+     image;              % An image for the button that will lanuch this layout
+     name;               % A unique name for instances of this class. 
+     shortDescription;   % A short descriptions used in tooltips.
+     nodeSize;           % The calculated node size, call dolayout() before accessing
+     centers;            % The calculated node centers in an n-by-2 matrix
+   end
+    
+   properties(GetAccess = 'protected', SetAccess = 'protected')
+        layoutFile = 'layout.dot';
+        adjFile   =  'adjmat.dot';
+   end
+    
+   methods
+     
+       function obj = Gvizlayout(name)
+       % constructor
+            if(nargin < 1)
+                obj.name = 'Gvizlayout';
+            else
+                obj.name = name;
+            end
+            load glicons;
+            obj.image = icons.energy;
+            obj.shortDescription = 'Minimum Energy Layout (GraphViz)';
+       end
+       
+       function available = isavailable(obj)
+        % Make sure graphViz is available. 
+            available = Gvizlayout.queryGviz('neato');
+            if(not(available))
+                  fprintf('Please install or upgrade graphViz\n');
+            end
+        end
+       
+       
+   end
+
+   
+   methods(Access = 'protected')
+       
+       function calcLayout(obj)
+       % Have graphViz calculate the layout
+          obj.writeDOTfile();
+          obj.callGraphViz();
+          obj.readLayout();
+          obj.cleanup();
+       end
+      
+       function writeDOTfile(obj)
+       % Write the adjacency matrix into a dot file that graphViz can
+       % understand. 
+            fid = fopen('adjmat.dot','w');
+            fprintf(fid,'digraph G {\ncenter = 1;\nsize="10,10";\n');
+            n = size(obj.adjMatrix,1);
+            for i=1:n, fprintf(fid,'%d;\n',i); end
+            edgetxt = ' -> ';
+            for i=1:n
+                for j=1:n
+                   if(obj.adjMatrix(i,j))
+                      fprintf(fid,'%d%s%d;\n',i,edgetxt,j);
+                   end
+                end 
+            end
+            fprintf(fid,'}');
+            fclose(fid);
+       end
+       
+       function callGraphViz(obj)
+       % Call GraphViz to determine an optimal layout. Write this layout in
+       % layout.dot for later parsing. 
+           err = system(['neato -Tdot -Gmaxiter=5000 -Gstart=7 -o ',obj.layoutFile,' ',obj.adjFile]);
+           if(err),error('Sorry, unknown GraphViz failure, try another layout'); end
+       end
+       
+       function readLayout(obj)
+       % Parse the layout.dot file for the graphViz node locations and 
+       % dimensions. 
+            fid = fopen(obj.layoutFile,'r');
+            text = textscan(fid,'%s','delimiter','\n'); 
+            fclose(fid);
+            text = text{:};
+            [start,dims] = strtok(text{cellfun(@(x)~isempty(x),strfind(text,'graph [bb="'))},'"');
+            dims = textscan(strtok(dims,'"'),'%n','delimiter',',');
+            dims = dims{:}';
+            text(cellfun(@(x)~isempty(x),strfind(text,' -> ')))=[]; % delete edge info, we don't need it
+            text(cellfun(@(x)isempty(x),strfind(text,'pos')))=[];   % keep only positions
+            [start,remaining] = strtok(text,'"');
+            [locations,remaining] = strtok(remaining,'"');
+            locations = cellfun(@(str)textscan(str,'%n','delimiter',','),locations,'UniformOutput',false);
+            locations = [locations{:}];
+            locations = [locations{:}]';
+            obj.scaleLocations(locations,dims);
+       end
+       
+       function scaleLocations(obj,locations,graphVizDims)
+       % Scale the graphViz node locations to the smartgraph dimensions and
+       % set the node size. 
+            dims = graphVizDims; loc = locations;
+            loc(:,1) = (loc(:,1)-dims(1)) ./ (dims(3)-dims(1))*(obj.xmax - obj.xmin) + obj.xmin;
+            loc(:,2) = (loc(:,2)-dims(2)) ./ (dims(4)-dims(2))*(obj.ymax - obj.ymin) + obj.ymin;
+            obj.centers = loc;
+            
+            a = min(abs(loc(:,1) - obj.xmin));
+            b = min(abs(loc(:,1) - obj.xmax));
+            c = min(abs(loc(:,2) - obj.ymin));
+            d = min(abs(loc(:,2) - obj.ymax));
+            obj.nodeSize = min(2*min([a,b,c,d]),obj.maxNodeSize);
+            
+       end
+       
+       function cleanup(obj)
+       % delete the temporary files. 
+           delete(obj.adjFile);
+           delete(obj.layoutFile);
+       end
+       
+   end
+  
+   methods(Access = 'protected',Static = true)
+      
+       function available = queryGviz(name)
+            err = system([name,' -V']);
+            available = ~err;
+       end
+       
+   end
+   
+ 
+end % end of graphVIZlayout class