3 Copyright (c) 2004 Trustees of Indiana University
5 Distributed under the Boost Software License, Version 1.0.
6 (See accompanying file LICENSE_1_0.txt or copy at
7 http://www.boost.org/LICENSE_1_0.txt)
10 <Title>Boost Graph Library: Gürsoy-Atun Layout</Title>
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32 <TT>gursoy_atun_layout</TT>
39 <em>// Non-named parameter version</em>
40 template<typename VertexListAndIncidenceGraph, typename Topology,
41 typename PositionMap, typename VertexIndexMap,
42 typename EdgeWeightMap>
44 gursoy_atun_layout(const VertexListAndIncidenceGraph& g,
45 const Topology& space,
47 int nsteps = num_vertices(g),
48 double diameter_initial = sqrt((double)num_vertices(g)),
49 double diameter_final = 1,
50 double learning_constant_initial = 0.8,
51 double learning_constant_final = 0.2,
52 VertexIndexMap vertex_index_map = get(vertex_index, g),
53 EdgeWeightMap weight = dummy_property_map());
55 <em>// Named parameter version</em>
56 template<typename VertexListAndIncidenceGraph, typename Topology,
57 typename PositionMap, typename P, typename T, typename R>
59 gursoy_atun_layout(const VertexListAndIncidenceGraph& g,
60 const Topology& space,
62 const bgl_named_params<P,T,R>& params = <em>all defaults</em>);
67 <P> This algorithm [<A HREF="bibliography.html#gursoy00">60</A>]
68 performs layout of directed graphs, either weighted or unweighted. This
69 algorithm is very different from the <a
70 href="kamada_kawai_spring_layout.html">Kamada-Kawai</a> and <a
71 href="fruchterman_reingold.html">Fruchterman-Reingold</a> algorithms,
72 because it does not explicitly strive to layout graphs in a visually
73 pleasing manner. Instead, it attempts to distribute the vertices
74 uniformly within a <em>topology</em> (e.g., rectangle, sphere, heart shape),
75 keeping vertices close to their neighbors; <a href="topology.html">various
76 topologies</a> are provided by BGL, and users can also create their own. The
79 href="http://davis.wpi.edu/~matt/courses/soms/">Self-Organizing
83 <a href="topology.html#square_topology"><img src="figs/ga-square.png"></a>
84 <a href="topology.html#heart_topology"><img src="figs/ga-heart.png"></a>
85 <a href="topology.html#circle_topology"><img src="figs/ga-circle.png"></a>
88 <h3>Where Defined</h3>
90 <a href="../../../boost/graph/gursoy_atun_layout.hpp"><tt>boost/graph/gursoy_atun_layout.hpp</tt></a>
94 IN: <tt>const Graph& g</tt>
96 The graph object on which the algorithm will be applied. The type
97 <tt>Graph</tt> must be a model of <a
98 href="./VertexAndEdgeListGraph.html">Vertex List Graph</a> and <a
99 href="IncidenceGraph.html">Incidence Graph</a>.
102 IN: <tt>const Topology& space</tt>
104 The topology on which the graph will be laid out. The type must
105 model the <a href="topology.html#topology-concept">Topology</a> concept.
108 OUT: <tt>PositionMap position</tt>
110 The property map that stores the position of each vertex. The type
111 <tt>PositionMap</tt> must be a model of <a
112 href="../../property_map/doc/LvaluePropertyMap.html">Lvalue Property
113 Map</a> such that the vertex descriptor type of <tt>Graph</tt> is
114 convertible to its key type. Its value type must be
115 <tt>Topology::point_type</tt>.
118 IN: <tt>int nsteps</tt>
120 The number of iterations to perform.<br>
121 <b>Default</b>: <tt>num_vertices(g)</tt>
124 IN: <tt>double diameter_initial</tt>
126 When a vertex is selected to be updated, all vertices that are
127 reachable from that vertex within a certain diameter (in graph
128 terms) will also be updated. This diameter begins at
129 <tt>diameter_initial</tt> in the first iteration and ends at
130 <tt>diameter_final</tt> in the last iteration, progressing
131 exponentially. Generally the diameter decreases, in a manner similar to
132 the cooling schedule in <a
133 href="fruchterman_reingold.html">Fruchterman-Reingold</a>. The
134 diameter should typically decrease in later iterations, so this value
135 should not be less than <tt>diameter_final</tt>.<br>
136 <b>Default</b>: <tt>sqrt((double)num_vertices(g))</tt>
139 IN: <tt>double diameter_final</tt>
141 The final value of the diameter.<br>
145 IN: <tt>double learning_constant_initial</tt>
147 The learning rate affects how far vertices can moved to rearrange
148 themselves in a given iteration. The learning rate progresses
149 linearly from the initial value to the final value, both of which
150 should be between 0 and 1. The learning rate should typically
151 decrease, so the initial value should not exceed the final
152 value.<br> <b>Default</b>: 0.8
155 IN: <tt>double learning_constant_final</tt>
157 The final learning rate constant.<br>
161 IN: <tt>VertexIndexMap vertex_index_map</tt>
163 This maps each vertex to an integer in the range <tt>[0,
164 num_vertices(g))</tt>. This is only necessary when no
165 displacement map is provided.
166 The type <tt>VertexIndexMap</tt> must be a model of <a
167 href="../../property_map/doc/ReadablePropertyMap.html">Readable Property
168 Map</a>. The value type of the map must be an integer type. The
169 vertex descriptor type of the graph needs to be usable as the key
171 <b>Default:</b> <tt>get(vertex_index, g)</tt>
172 Note: if you use this default, make sure your graph has
173 an internal <tt>vertex_index</tt> property. For example,
174 <tt>adjacenty_list</tt> with <tt>VertexList=listS</tt> does
175 not have an internal <tt>vertex_index</tt> property.
178 IN: <tt>EdgeWeightMap weight</tt>
180 This maps each edge to a weight.
181 The type <tt>EdgeWeightMap</tt> must be a model of <a
182 href="../../property_map/doc/ReadablePropertyMap.html">Readable Property
183 Map</a>. The value type of the map must be an floating-point type
184 compatible with <tt>double</tt>. The edge descriptor type of the
185 graph needs to be usable as the key type of the map. When this map
186 is a <tt>dummy_property_map</tt>, the algorithm assumes the graph is
188 <b>Default:</b> <tt>dummy_property_map()</tt>
191 <h3>Named Parameters</h3>
193 IN: <tt>iterations(int n)</tt>
195 Executes the algorithm for <em>n</em> iterations.<br>
196 <b>Default:</b> <tt>num_vertices(g)</tt>
199 IN: <tt>diameter_range(std::pair<T, T> range)</tt>
201 Range specifying the parameters (<tt>diameter_initial</tt>, <tt>diameter_final</tt>). <br>
202 <b>Default:</b> <tt>std::make_pair(sqrt((double)num_vertices(g)), 1.0)</tt>
205 IN: <tt>learning_constant_range(std::pair<T, T> range)</tt>
207 Range specifying the parameters (<tt>learning_constant_initial</tt>, <tt>learning_constant_final</tt>). <br>
208 <b>Default:</b> <tt>std::make_pair(0.8, 0.2)</tt>
211 IN: <tt>edge_weight(EdgeWeightMap weight)</tt>
213 Equivalent to the non-named <tt>weight</tt> parameter.<br>
214 <b>Default:</b> <tt>dummy_property_map()</tt>
217 IN: <tt>vertex_index_map(VertexIndexMap i_map)</tt>
219 Equivalent to the non-named <tt>vertex_index_map</tt> parameter.<br>
220 <b>Default:</b> <tt>get(vertex_index, g)</tt>
221 Note: if you use this default, make sure your graph has
222 an internal <tt>vertex_index</tt> property. For example,
223 <tt>adjacency_list</tt> with <tt>VertexList=listS</tt> does
224 not have an internal <tt>vertex_index</tt> property.
231 <TD nowrap>Copyright © 2004 Trustees of Indiana University</TD><TD>
232 Jeremiah Willcock, Indiana University (<script language="Javascript">address("osl.iu.edu", "jewillco")</script>)<br>
233 <A HREF="http://www.boost.org/people/doug_gregor.html">Doug Gregor</A>, Indiana University (<script language="Javascript">address("cs.indiana.edu", "dgregor")</script>)<br>
234 <A HREF="http://www.osl.iu.edu/~lums">Andrew Lumsdaine</A>,
235 Indiana University (<script language="Javascript">address("osl.iu.edu", "lums")</script>)