Network Diagram

When to use a network diagram

A lot of times, real-world information comes in the form of relationships between entities/items - people who know each other (social networks), Web pages that are connected to each other, etc. In a network diagram, entities are connected to each other in the form of a node and link diagram.

How the network diagram works

A network consists of a set of objects called vertices connected by edges. The visualization of the network is optimized to keep strongly related items in close proximity to each other. In this way, the overall arrangement of vertices in the network is very telling of the structure of the connections between vertices (vertices that are far away are weakly related to each other). In this visualization, the size of a vertex is proportional to the number of edges emanating from it.

The network display in ManyEyes is fully interactive and can be zoomed and panned to obtain a detailed view of different sections of the graph:

Pan : Click and drag using the right mouse button to view a different area of the graph.
Zoom : Use the mousewheel or drag a rectangle over the area of interest using the left mouse button. Alternatively, one can use the and buttons on the bottom to zoom in and out. The whole graph can be brought back into view by clicking the view reset button.

Selection : Nodes can be highlighted by selecting them with the left mouse button. If desired, you can manually fine-tune the layout by selecting the nodes to be moved and dragging them to their new positions. The entire layout can be recomputed using the button at the bottom of the screen.

Direction : If the direction of links is relevant to your dataset you can optionally toggle arrowheads on edges by clicking the link toggle button.

Data requirements

A network diagram takes a table consisting of at least two text columns of data, with each row representing a single relationship between two items. The colmnn contents are interpreted as the display label for each item. Please keep in mind that in general, the layout optimization process can be very time consuming for larger networks (more than a thousand vertices) especially when running in a browser. In most cases the applet will eventually compute a correct layout in a few minutes, however. Also, this technique is not very well suited for networks in which a lot of nodes have a large number of neighbors.

An example data set suitable for the network diagram would be: