Working with Location data

Zegami provides a unique and highly visual way to explore data sets that contain location or spatial data. However in order to get the most out of Zegami your data must first be in the correct format.

ISO 6709 Annex H String Expression

ISO 670... what? So that Zegami can understand that a data item has location information associated with it the specific coordinate data must be represented in a certain format. The details of the ISO 6709 specification can be found in this article https://en.wikipedia.org/wiki/ISO_6709

In short when representing location in a data file the Latitude and Longitude must be joined together in a single piece of text. The values must be prefixed with a positive + or negative - sign and end with a trailing /.

For example the Eiffel Tower, located at Latitude 48.8577 and Latitude 002.295 is encoded as:

+48.8577+002.295/

When loading a data set that contains a column in this format, Zegami will automatically detect that the collection contains location information and will enable the Map View and Location filter.

You can confirm that the automatic detection worked when looking at the Column Options page when creating or editing a collection.

Map View

Collections that have a Geo type column will automatically have the map view enabled. You can switch to the map view via the Visualisation Types menu.

Each item is represented as a pin on the map.

Items that are close to each other are collapsed into a single item to save space. Zooming in on a collapsed item will expand it out to individual points.

Selecting an individual pin will display the image for the individual item as well as the metadata panel.

Location Filter

Expanding a Geo type column in the filter panel will display a mini map with all the points plotted on it. To select a group of points on the map, simply draw or lasso an area around the points of interest.