REFLECTION: THE ANATOMY OF A TABLEAU MAP
When you create a map by adding a geographic field (a dimension marked with the globe symbol) to the view, the following processes happen in the background:
- Tableau looks up the longitude and latitude of the geographic entries and adds the information to two new fields. These fields are added to the Rows and Column shelves and provide the coordinates for the chart's marks.
- In the case of filled maps, Tableau looks up the shapes of the different geographic areas and styles the marks accordingly.
- Tableau also adds a background map to provide more context for the individual marks. By default, this map is provided by OpenStreetMap.
You can manually intervene in all three of these processing steps, to fine‐tune your chart or to create even more advanced maps.
If a dimension is not recognized as a geographic field, you can provide the coordinates manually by adding latitude and longitude as separate fields. For example, you may have a list...