source: orange/orange/doc/widgets/Associate/NetExplorer.htm @ 9399:6bbe263e8bcf

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Renaming widgets catalog.

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1<html>
2<head>
3<title>Net Explorer</title>
4<link rel=stylesheet href="../../../style.css" type="text/css" media=screen>
5<link rel=stylesheet href="../../../style-print.css" type="text/css" media=print></link>
6</head>
7
8<body>
9
10<h1>Net Explorer</h1>
11<img class="screenshot" src="../icons/NetExplorer.png">
12<p>Interactive network exploration widget.</p>
13
14<h2>Channels</h2>
15
16<h3>Inputs</h3>
17<DL class=attributes>
18<DT>Network (Network)</DT>
19<DD>Network object to plot.</DD>
20<DT>Items (ExampleTable)</DT>
21<DD>Additional data about vertices, one example for each vertex.</DD>
22<DT>Items to Mark (ExampleTable)</DT>
23<DD>A subset from items instances to mark.</DD>
24<DT>Items Subset (ExampleTable)</DT>
25<DD>A subset from items instances to show. All other instances will be hidden.</DD>
26<DT>Vertex Distance (SymMatrix)</DT>
27<DD>Distance matrix with distances between vertices.</DD>
28</dl>
29
30<h3>Outputs</h3>
31<DL class=attributes>
32<DT>Selected Network (Network)</DT>
33<DD>Subnetwork of all selected nodes.</DD>
34<DT>Selected Examples (ExampleTable)</DT>
35<DD>Descriptions of vertices (from the graph of input signal Items) that correspond to selected vertices.</DD>
36<DT>Unselected Examples (ExampleTable)</DT>
37<DD>Descriptions of vertices corresponding to unselected vertices.</DD>
38<DT>Marked Examples (ExampleTable)</DT>
39<DD>Descriptions of vertices corresponding to marked vertices.</DD>
40</dl>
41
42<h2>Description</h2>
43<p>Net Explorer visualizes graphs, lets the user explore them by selecting their
44individual parts and gives the corresponding data to other widgets. It is currently available
45only in the latest (Qt4) version of Orange.</p>
46
47<p>More information on the use the widget from Python is available in documentation on <a href="../../../modules/orngNetwork.htm">
48orngNetwork Orange module</a>.</p>
49
50<a href="NetExplorer.png"><img class="screenshot"
51src="NetExplorer-S.png" alt="Classification Tree Graph
52- Node Tab" border=0></a></center>
53
54<h3>Navigation</h3>
55<p>Four navigation buttons are located in the upper right corner of the control area.</p>
56
57<table>
58<tr valign="top"><td><img class="leftscreenshot" src="NetExplorer-navigation.png"/></td>
59
60<td>
61<p><i>Zooming:</i></p>
62<p>Zooming mode is selected by default. User can zoom in a rectangle by pressing and holding the
63left mouse button and dragging the mouse to draw a rectangle to zoom in to. Zoom out (one level)
64command can then be executed by pressing right mouse button.</p>
65
66<p><i>Zoom to extent:</i></p>
67<p>By pressing this button the zoom is automatically set to show all visible nodes in the network.</p>
68
69<p><i>Zoom selection:</i></p>
70<p>By pressing this button the zoom is automatically set to show all selected nodes in the network.</p>
71
72<p><i>Panning:</i></p>
73<p>Use this mode to drag the network around the canvas.</p>
74</td></tr>
75</table>
76
77<h3>Marking and Selecting</h3>
78<p>The widget features a two-stage procedure for selection of vertices, which allows for a very flexible
79manipulation of subsets of vertices. Vertices can be marked and/or selected. Marked vertices are presented
80by filled circled and selected vertices are highlighted with a yellow border.</p>
81
82<table>
83<tr valign="top"><td><img class="leftscreenshot" src="NetExplorer-select.png"/></td>
84
85<td>
86<p>Vertices can be selected manually by clicking or by drawing selection rectangle. Selection mode is
87enabled by pressing fifth button from the top in the upper right corner in control area.
88</td></tr>
89
90<tr>
91<tr valign="top"><td><img class="leftscreenshot" src="NetExplorer-MarkSelect.png"/></td>
92<td> Another way to
93select vertices is to add or remove the marked vertices to or from the selection, or to replace the
94current selection with the marked vertices (buttons seven to nine).</p>
95</td></tr>
96</table>
97<p>The vertices can be marked based upon values of the attributes of the corresponding objects. Most marking
98options are available in the Mark Tab.</p>
99
100<h3>Vertices Tab</h3>
101
102<img class="leftscreenshot" src="NetExplorer-vertices.png" width="237"/>
103<p>Parameters in vertices tab govern the appearance of network vertices and data associated with them.
104User can select optimization method, vertex color and size attribute, set the labels and tooltips and
105other rendering options.</p>
106
107<h4><b>Optimization methods</b></h4>
108<dl>
109<dt>No optimization</dt>
110<dd>The vertices are left as they are. If the
111 given network object already contains the vertices placement
112 data (these can be given, for instance, in Pajek format), they
113 are placed accordingly, otherwise their positions are random.</dd>
114 
115<dt>Random</dt>
116<dd>The vertices are scattered randomly.</dd>
117
118<dt>Fruchterman-Reingold</dt>
119<dd> The standard Fruchterman-Reingold algorithm, which
120 tries to put the pairs of connected vertices to a certain fixed
121 small distance and the unconnected ones to the fixed large
122 distance. A simulated annealing optimization algorithm is used
123 to minimize the stress of the solution.</dd>
124 
125<dt>Fruchterman-Reingold Weighted</dt>
126<dd> A variation of the Fruchterman-Reingold algorithm which also
127 takes the edge weights into account: the larger the weight, the
128 smaller the desired distance between the two vertices.</dd>
129 
130<dt>Fruchterman-Reingold Radial</dt>
131<dd> A Fruchterman-Reingold-type algorithm which places a vertex
132 selected by the user at the center of the graph and optimizes
133 the layout around it. The optimization procedure ensures that
134 vertices with shorter paths to the central vertex are closer to
135 it than those with longer paths.</dd>
136 
137<dt>Circular</dt>
138<dd> The vertices are placed around the circle in the same order in
139 which they are given in the data.</dd>
140
141<dt>Circular crossing reduction</dt>
142<dd> A local optimization algorithm which puts the vertices on the
143 circle and tries to minimize the number of crossed edges.</dd>
144 
145<dt>Circular random</dt>
146<dd> The vertices are placed randomly around the circle.</dd>
147</dl>
148
149<p>The user can specify the number of iterations of the optimization procedure where applicable.</p>
150
151<h4>Labels and tooltips</h4>
152
153<p>One or more attributes can be chosen to be shown as <span class="option">Vertex labels or tooltips</span>.
154To reduce the visual clutter, the user can also decide to <span class="option">Show labels on marked vertices only</span>.
155Checking <span class="option">Inside view</span> enables a special mode in which only selected vertex and vertices
156closer to it than the specified distance (in terms of the number of connections, not their lengths) are shown.</p>
157
158<p><span class="option">Show missing values</span> decides whether missing values should be displayed (as question marks).</p>
159
160<h3 style="clear: both">Edges Tab</h3>
161
162<img class="leftscreenshot" src="NetExplorer-edges.png" width="238" />
163
164<p>Parameters in edges tab are used to specify the appearance of edges. One can set edges color, width and
165whether weights of edges are displayed.</p>
166
167<p>When <span class="option">Explore vertex distances</span> is selected, the user can examine the distance between vertices, as given in the "Vertex Distance" signal. To display the distance, one must first select a vertex. When hovering over an arbitrary vertex, the distance between the selected vertex and the vertex under the mouse pointer is displayed as a popup.</p>
168
169<h3 style="clear: both">Mark Tab</h3>
170
171<img class="leftscreenshot" src="NetExplorer-Mark.png" width="238" />
172
173<p>Most options for interactive network exploration are gathered here. User can search for nodes by value in items meta
174data, mark neighbours of selected vertices or mark vertices by number of connections.</p>
175
176<!-- mislim, da tole ni potrebno, saj je ocitno iz slike. bi pa bilo to smiselno nasteti, ce bi o vsakem kaj povedal. a skoraj ni kaj
177<p><i>Complete list of marking features:</i></p>
178<ul>
179<li>mark neighbours of focused vertex,</li>
180<li>mark neighbours of selected vertex,</li>
181<li>mark vertices with at list N connections,</li>
182<li>mark vertices with at most N connections,</li>
183<li>mark vertices with more connections than any neighbour,</li>
184<li>mark vertices with more connections than average neighbour,</li>
185<li>find hubs (vertices with the most connections),</li>
186<li>mark vertices specified in input signal (Items to Mark signal).</li>
187</ul>
188-->
189
190<h3 style="clear: both">Info Tab</h3>
191
192<img class="leftscreenshot" src="NetExplorer-Info.png" width="238" />
193
194<p>The info tab gives some general information (such as number of vertices, number of edges, diameter, clustering coefficient) about the network. Button <span class="option">Degree Distribution</span> calculates and displays the degree distribution. Finally, the network can be saved in <a href="http://pajek.imfm.si/doku.php">Pajek</a> format by clicking on <span class="option">Save network</span> button.</p>
195
196<h2>Examples</h2>
197<p>The best way to get to know how to use this widget is by playing with it. Try some of the following network data sets:</p>
198
199<ul>
200<li><a href="NetExplorer-K2K4.net">K2K4</a>, a network containing two full graphs (one with 2 vertices, other with 4);</li>
201<li><a href="NetExplorer-K8.net">K8</a>, ful graph with 8 vertices;</li>
202<li><a href="NetExplorer-Cube.net">cube</a>, a cube;</li>
203<li><a href="NetExplorer-Star.net">star</a>, a star with 6 vertices;</li>
204<li><a href="NetExplorer-Rose.net">rose</a>, a rose like graph with 19 vertices;</li>
205<li><a href="NetExplorer-Lattice.net">lattice</a>, a lattice with 100 vertices;</li>
206<li><a href="NetExplorer-lastfm_artists.net">last.fm network</a> and <a href="NetExplorer-lastfm_artists.tab">last.fm items</a>, a network where similar artists are connected. Data was aquired from the <a href="http://www.last.fm/">last.fm web site</a>.</li>
207</ul>
208
209<p>More comprehensive list of examples will be available soon.</p>
210
211</body>
212</html>
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