first steps

• Main Window
• Network Model
• Using the Main View
• Analysis
• Visualization

From the top to the bottom the main window of visone consists of the following elements :

visone main window

• the menu bar
• the toolbar
• an overview of the network
• a control area
• the main network view
• the status bar

Together with to control area the menu bar provides access to all functions of visone. While the analysis and visualization methods are accessible via the control area, the menu bar contains standard functions like open and save, print, general graph layout methods, zoom, etc.

A quick access to the most commonly used functions of the menu is available by icons in the toolbar below the menu bar. From left to right, the functions are:

• new, open, save network
• undo and redo
• zoom
• switch the edit mode

The overview shows a sketch of the whole current network. A shaded box depicts the part of the network currently visible in the main view.

The control area provides quick access to some of the commonly used functions of visone. There are tabs for using the analysis and visualization methods, for selecting templates for the appearance of vertices and edges, and for handling grouped graph elements.

The main network view, or main view, shows the network in all details. Furthermore, it can be used for manipulation the network, e.g. you can add or delete vertices and edges, move them around, and change their appearance, and to see the result of a visualization.

You can open multiple networks at the same time. Views of different networks are placed in different network views accessible via tabs at the top of the main view area. All functions in visone apply to the currently visible network.

The status bar at the bottom of the main window shows the number of vertices and edges the current network has.

The network model in visone is very permissive. A network may contain directed and undirected links, multi-links, and self-loops at the same time.

different link types (confirmed directed, confirmed undirected, and unconfirmed directed with different confirming actors)

Besides this, links have the special property confirmation. Confirmation can be used to display different opinions of the concerned actors about existence or characteristics of a link. Therefore, confirmation is a directed property.

How to regard unconfirmed links in an analysis is a controversial topic, therefore is choice is left to the user. By default, an analysis method does not consider unconfirmed links at all, but the user can choose which links to consider by simply selecting them.

User data can be added to the actors and links in unlimited size, called attributes in visone. Each attribute has a name and a type, i.e. binary, decimal, integer, text, or list. Attributes can be either data imported from a file, entered directly by the user, or the result of an analysis, and are used as parameters for the selection of network elements, an analysis method, or an visualization algorithm.

The main network view, or main view, shows the network in all details. Furthermore, it can be used for manipulation the network, e.g. you can add or delete vertices and edges, move them around, and change their appearance, and to see the result of a visualization.

There are three use modes in visone changing the allowed mouse commands and therefore the edit options the user has. These modes are

• edit mode
• analysis mode
• zoom mode

The edit mode allows the creation and deletion of actors and links by mouse clicking. New actors can be created by clicking on an empty space in the view. Links are created by successively clicking on a source actor and on an target actor.

In the analysis mode the network structure can not by changed by simple mouse commands. Instead, network elements can be selected by clicking on them or by dragging a selection box. You can use the Control-key to add new elements to an already existing selection. You can also move selected elements by dragging them around.

In the zoom mode you can zoom in and out by clicking in the view with the left resp. the right mouse button and move the viewing area by dragging the mouse.

analysis tab

The analysis methods are accessible using the analysis tab in the control area. They are grouped according to the level they operate on, i.e. Actor and Link, Group, and Network, and the objective the compute, e.g. centrality or connectedness. Generally, the result of an analysis is stored in an attribute which can be used as parameter for various visualization algorithms. Note, that unconfirmed links are only considered by an analysis if they are selected (see also section confirmation).

Available analysis methods include actor-level centrality indices, e.g. closeness, betweenness, and pagerank, cohesive subgroups like cliques, k-cliques, and k-clans, and connectedness.

Some algorithms, e.g. a k-clique computation in large networks for large parameter k, may take a while to finish. Therefore, the analysis tab features a progress indicator allowing the user to interrupt the computation.

visualization tab

Visualization algorithms are chosen in the layout tab in the control bar. Here you can select an attribute as input parameter and other properties of the algorithms. The final layout is shown directly in the main view.

Available visualization algorithms include scaling of actors and links sizes according to values, assigning collors to actors and links, radial layout, and group highlighting.

highlighting the k-core shells

centrality layout of status centrality