List of Figures

 

Chapter 1. What is a spatial database?

Figure 1.1. Pushpin madness!

Figure 1.2. The basic geometries: a point, a linestring, and a polygon

Figure 1.3. The Utah salt flats—we can model them with linestrings, points, and polygons.

Figure 1.4. Linestrings and polygons created in the following code snippets

Figure 1.5. The Plugins menu of pgAdmin III shows the PostGIS Shapefile and DBF loader.

Figure 1.6. Loading into the geometry data type

Figure 1.7. Loading data into the geography data type. We pretend our data is 4326 instead of 4269 because they’re similar. We go ahead and index and check the load into geography.

Figure 1.8. U.S. Route 1 in Maryland, with three Hardee’s restaurants in the 10-mile buffer, and the 10-mile buffer around the route

Chapter 2. Geometry types

Figure 2.1. Three points created using the code in listing 2.1

Figure 2.2. Open and closed linestrings created using the code in listing 2.2. The points that make up the lines are shown as well.

Figure 2.3. A non-simple linestring tested for simplicity

Figure 2.4. Triangle-shaped polygon

Figure 2.5. Polygon with interior rings (holes)

Figure 2.6. We model the Seattle area as a polygon with two rings. Lake Washington fills up the hole. We’re also overlooking the existence of Mercer Island in the lake, which would make this a multipolygon.