C++ Boost

write_graphviz

(1)
template < typename VertexListGraph >
void 
write_graphviz(std::ostream& out, const VertexListGraph& g);

(2)
template < typename VertexListGraph, typename VertexPropertyWriter >
void 
write_graphviz(std::ostream& out, const VertexListGraph& g, 
               VertexPropertyWriter vpw);

(3)
template < typename VertexListGraph, typename VertexPropertyWriter,
           typename EdgePropertyWriter >
void
write_graphviz(std::ostream& out, const VertexListGraph& g, 
               VertexPropertyWriter vpw, EdgePropertyWriter epw);

(4)
template < typename VertexListGraph, typename VertexPropertyWriter,
           typename EdgePropertyWriter, typename GraphPropertyWriter >
void 
write_graphviz(std::ostream& out, const VertexListGraph& g, 
               VertexPropertyWriter vpw, EdgePropertyWriter epw, 
               GraphPropertyWriter gpw);

This is to write a BGL graph object into a output stream in graphviz dot format so that users can make use of AT&T graphviz to draw a picture with nice layout.

The first version with two parameters will write graph into an std::ostream where vertex is represented by numerical vertex IDs. If users have either interior or exterior properties for each vertex in the graph, the second version above provides a way to print those properties into the gaphviz format file. For example, if each vertex in the graph has its label through property map object name, users can use the second version:

  write_graph(out, g, make_label_writer(name));
The utility function make_label_writer returns a predefined PropertyWriter for vertex label. Similarly, the third version and fourth version require edge PropertyWriter, edge PropertyWriter and graph PropertyWriter, respectively.

PropertyWriter

PropertyWriter is used in the write_graphviz function to print properties of vertex, edge or graph. There are two types of PropertyWriter. One is for a vertex or edge. The other is for a graph. Thus, users could easily extend the write_graphviz function by creating their own PropertyWriter only.

A PropertyWriter for vertices or edges is a functor which is to print a series of "name=value" separated with spaces or a comma or a semicolon in square bracket into an std::ostream. The following functor is the example of PropertyWriter for vertices or edges. It is used to print the label of each vertex or edge.

  template < class Name >
  class label_writer {
  public:
    label_writer(Name _name) : name(_name) {}
    template 
    void operator()(std::ostream& out, const VertexOrEdge& v) const {
      out << "[label=\"" << name[v] << "\"]";
    }
  private:
    Name name;
  };

A PropertyWriter for graph is a functor which is to print a series graph properties into an std::ostream. The following code excerpt is an example of a PropertyWriter for a graph.

  struct sample_graph_writer {
    void operator()(std::ostream& out) const {
      out << "graph [bgcolor=lightgrey]" << std::endl;
      out << "node [shape=circle color=white]" << std::endl;
      out << "edge [style=dashed]" << std::endl;
    }
  };
}

Parameters

For version 1:

OUT: std::ostream& out

A standard std::ostream object.
IN: VertexListGraph& g
A directed or undirected graph. The graph's type must be a model of VertexListGraph.
For version 2:

OUT: std::ostream& out

A standard std::ostream object.
IN: VertexListGraph& g
A directed or undirected graph. The graph's type must be a model of VertexListGraph.
IN: VertexPropertyWriter vpw
A functor that models PropertyWriter concept to print properties of a vertex.
For version 3:

OUT: std::ostream& out

A standard std::ostream object.
IN: VertexListGraph& g
A directed or undirected graph. The graph's type must be a model of VertexListGraph.
IN: VertexPropertyWriter vpw
A functor that models PropertyWriter concept to print properties of a vertex.
IN: EdgePropertyWriter epw
A functor that models PropertyWriter concept to print properties of an edge.
For version 4:

OUT: std::ostream& out

A standard std::ostream object.
IN: VertexListGraph& g
A directed or undirected graph. The graph's type must be a model of VertexListGraph.
IN: VertexPropertyWriter vpw
A functor that models PropertyWriter concept to print properties of a vertex.
IN: EdgePropertyWriter epw
A functor that models PropertyWriter concept to print properties of an edge.
IN: GeaphPropertyWriter epw
A functor that models PropertyWriter concept to print properties of a graph.

Example

This example demonstrates using BGL-graphviz interface to write a BGL graph into a graphviz format file.
enum files_e { dax_h, yow_h, boz_h, zow_h, foo_cpp, 
               foo_o, bar_cpp, bar_o, libfoobar_a,
               zig_cpp, zig_o, zag_cpp, zag_o, 
                 libzigzag_a, killerapp, N };
const char* name[] = { "dax.h", "yow.h", "boz.h", "zow.h", "foo.cpp",
                       "foo.o", "bar.cpp", "bar.o", "libfoobar.a",
                       "zig.cpp", "zig.o", "zag.cpp", "zag.o",
                       "libzigzag.a", "killerapp" };

int main(int,char*[])
{
    
  typedef pair Edge;
  Edge used_by[] = {
    Edge(dax_h, foo_cpp), Edge(dax_h, bar_cpp), Edge(dax_h, yow_h),
    Edge(yow_h, bar_cpp), Edge(yow_h, zag_cpp),
    Edge(boz_h, bar_cpp), Edge(boz_h, zig_cpp), Edge(boz_h, zag_cpp),
    Edge(zow_h, foo_cpp), 
    Edge(foo_cpp, foo_o),
    Edge(foo_o, libfoobar_a),
    Edge(bar_cpp, bar_o),
    Edge(bar_o, libfoobar_a),
    Edge(libfoobar_a, libzigzag_a),
    Edge(zig_cpp, zig_o),
    Edge(zig_o, libzigzag_a),
    Edge(zag_cpp, zag_o),
    Edge(zag_o, libzigzag_a),
    Edge(libzigzag_a, killerapp)
  };
  const int nedges = sizeof(used_by)/sizeof(Edge);
  int weights[nedges];
  fill(weights, weights + nedges, 1);

  typedef adjacency_list< vecS, vecS, directedS, 
      property< vertex_color_t, default_color_type >,
      property< edge_weight_t, int >
    > Graph;
  Graph g(N, used_by, used_by + nedges, weights);

  write_graphviz(std::cout, g, make_label_writer(name));
}
The output will be:
digraph G {
0 -> 4;
0 -> 6;
0 -> 1;
0 [label="dax.h"];
1 -> 6;
1 -> 11;
1 [label="yow.h"];
2 -> 6;
2 -> 9;
2 -> 11;
2 [label="boz.h"];
3 -> 4;
3 [label="zow.h"];
4 -> 5;
4 [label="foo.cpp"];
5 -> 8;
5 [label="foo.o"];
6 -> 7;
6 [label="bar.cpp"];
7 -> 8;
7 [label="bar.o"];
8 -> 13;
8 [label="libfoobar.a"];
9 -> 10;
9 [label="zig.cpp"];
10 -> 13;
10 [label="zig.o"];
11 -> 12;
11 [label="zag.cpp"];
12 -> 13;
12 [label="zag.o"];
13 -> 14;
13 [label="libzigzag.a"];
14;
14 [label="killerapp"];
edge[style="dotted"];
6 -> 0;
}

See Also

read_graphviz

Notes

Note that you can use Graphviz dot file write facilities without the library libbglviz.a.

Copyright © 2000-2001 Lie-Quan Lee, Indiana University (llee@cs.indiana.edu)
Jeremy Siek, Indiana University (jsiek@osl.iu.edu)