Spatial data contains
the coordinates and identifying information describing the map itself.
Attribute data contains
information that can be linked to the spatial data, such as population and demographic information,
that matches addresses or coordinates in the spatial data.
The second type of data used in a GIS application is attribute data. With THE TOWN™ software,
data sets or data views can be associated with the map through links to the spatial data.
For instance, the spatial data might represent a county and contain information for city
boundaries, census tract boundaries, streets, and so forth. An attribute data set with population
information for each census tract can be linked to a map by the corresponding tract value
in the spatial data.
Some of the ways in which you can use attribute data include:
Using variables from the attribute data as themes for layers. For example, an attribute
data set containing population data could provide a theme for a map of census tracts.
Creating actions that display or manipulate the attribute data when features are selected
in the map. The actions can range from simple, such as displaying observations from an
attribute data set that relate to features in the map, to complex, such as submitting
queries to perform statistical analyses.
One of the key concepts with THE TOWN™ software is selecting features from the map and
then performing actions on the attribute data associated with those features. Actions can
be defined to:
- Display observations from the attribute data sets that relate to the selected map
- Open additional maps that relate to selected map features
- Display graphic images that relate to the selected map features
- Interactively subset the attribute data sets according to the subset of selected map
- Submit subsets of the attribute data that relate to the selected map features