`random_graph_layout`

Places the vertices of a graph at random locations within a given topology.

Complexity: O(|V|)
Defined in: <boost/graph/random_layout.hpp>

Example

#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/random_layout.hpp>
#include <boost/graph/topology.hpp>
#include <iostream>
#include <vector>

using namespace boost;
using Point = rectangle_topology<>::point_type;
using Graph = adjacency_list<vecS, vecS, undirectedS>;

int main() {
    Graph g(5);
    add_edge(0, 1, g); add_edge(1, 2, g);
    add_edge(2, 3, g); add_edge(3, 4, g);

    minstd_rand gen(42);
    rectangle_topology<> topology(gen, 0.0, 0.0, 100.0, 100.0);

    std::vector<Point> positions(num_vertices(g));
    auto pos_map = make_iterator_property_map(
        positions.begin(), get(vertex_index, g));

    random_graph_layout(g, pos_map, topology);

    for (auto v : make_iterator_range(vertices(g)))
        std::cout << "vertex " << v << ": ("
                  << positions[v][0] << ", " << positions[v][1] << ")\n";
}

vertex 0: (0.0944073, 57.1363)
vertex 1: (25.6809, 44.7674)
vertex 2: (65.4139, 96.697)
vertex 3: (62.8985, 71.6352)
vertex 4: (4.20589, 22.7523)

Positional version

template<typename Graph, typename PositionMap, typename Topology>
void random_graph_layout(
    const Graph& g,
    PositionMap position_map,
    const Topology& space);

Direction Parameter Description

Direction	Parameter	Description
IN	`const Graph& g`	The graph object on which the algorithm will be applied. The type `Graph` must be a model of Vertex And Edge List Graph.
IN/OUT	`PositionMap position_map`	The property map that stores the position of each vertex. The type `PositionMap` must be a model of Lvalue Property Map such that the vertex descriptor type of `Graph` is convertible to its key type. Its value type must be `Topology::point_type`, representing the coordinates of the vertex.
IN	`const Topology& space`	The topology used to lay out the vertices. This parameter describes both the size and shape of the layout area and provides a random number generator used to create random positions within the space. Topologies are described in more detail (with a list of BGL-provided topologies) in separate documentation.

const Graph& g

The graph object on which the algorithm will be applied. The type Graph must be a model of Vertex And Edge List Graph.

IN/OUT

PositionMap position_map

The property map that stores the position of each vertex. The type PositionMap must be a model of Lvalue Property Map such that the vertex descriptor type of Graph is convertible to its key type. Its value type must be Topology::point_type, representing the coordinates of the vertex.

const Topology& space

The topology used to lay out the vertices. This parameter describes both the size and shape of the layout area and provides a random number generator used to create random positions within the space. Topologies are described in more detail (with a list of BGL-provided topologies) in separate documentation.

Edit this Page