7.3.3 Using the Geographical Layout

The Graph Visualization application offers a choice of layouts for rendering graphs. One of them is the Geographical layout that will show the graph (vertices and edges) on a global map.

The following figure shows a graph rendered on a geographical layout in the Graph Visualization application:

Figure 7-4 Geographical Layout

Description of "Figure 7-4 Geographical Layout"

In order to view your vertices on a map, they must include a geographical location, in the form of a pair of properties that contain the longitude and latitude coordinates for that vertex. For example:

+-------------------------------------------------+
| iata | city        | longitude    | latitude    |
+-------------------------------------------------+
| SIN  | Singapore   | 103.994003   | 1.35019     |
| LAX  | Los Angeles | -118.4079971 | 33.94250107 |
| MUC  | Munich      | 11.7861      | 48.353802   |
| CDG  | Paris       | 2.55         | 49.012798   |
| LHR  | London      | -0.461941    | 51.4706     |
+-------------------------------------------------+

Note:

You can use any name for the longitude and latitude properties (such as X and Y, or long and lat). But, you must ensure that the longitude/latitude pair are in the WGS84 system (GPS coordinates), and the coordinates are expressed in decimal degrees.

You can select the geographical layout in the Graph Visualization settings window as shown:

Figure 7-5 Setting Geographical Layout

Description of "Figure 7-5 Setting Geographical Layout"

Then, select the properties in your vertices that contain the geographical coordinates as shown:

Figure 7-6 Selecting the Coordinates for the Geographical layout

Description of "Figure 7-6 Selecting the Coordinates for the Geographical layout"

You can now move around the map and zoom in/out using your mouse or trackpad. From now on, whenever you enter a new PGQL query, the map will automatically center and zoom the vertices returned by the query.