# `write_dimacs_max_flow`

    //outputs a graph with including edge_capacity properties to an std::ostream
    template < typename Graph, typename CapacityMap, typename IndexMap >
    void write_dimacs_max_flow(Graph& g,
                             CapacityMap capacity,
                             IndexMap idx,
                             typename graph_traits::vertex_descriptor& src,
                             typename graph_traits::vertex_descriptor& sink,
                             std::ostream& out)

This method writes a BGL graph object as an max-flow problem into an output stream in extended dimacs format (see `Goldbergs site` for more information). The output can be read in again using the `boost/graph/read_dimacs.hpp` method.

### Where Defined

`boost/graph/write_dimacs.hpp`

### Parameters

IN: `Graph& g`

> A directed or undirected graph. The graph's type must be a model of VertexListGraph and EdgeListGraph, as num_vertices(Graph) and num_edges(Graph) is used inside. [1]

IN: `CapacityMap capacity`

> A property map that models Readable Property Map whose key type is the edge descriptor of the graph and whose value type can be written to a stream.

IN: `IndexMap epw`

> A property map that models Readable Property Map whose key type is the vertex descriptor of the graph and whose value type can be written to a stream.

OUT: `std::ostream& out`

> A standard `std::ostream` object.

### Example

A short example which uses read_dimacs and write_dimacs is located in the examples directory.

### See Also

`read_dimacs`

### Notes

[1] As num_edges() and num_vertices() is used inside which returns values for the unfiltered graph (instead of the filtered), this method cannot be used with a filtered_graphSee filtered_graph Note [2] for the reason.