Demographic Data Analysis

Spatial Data

Spatial data contain the coordinates and identifying information for various map features. Three types of features can be represented in the map: points, lines, and areas. The various physical aspects of the map (political boundaries, roads, railroads, waterways, etc.) are organized into layers according to their common features.

For example, the collection of points that represent park locations can be organized into a parks layer, the collection of lines that represent streets can be organized into a streets layer, and the collection of areas that represent census tracts can be organized into a tracts layer.

Static and Dynamic Layers

A layer can be either static or dynamic. Static layers use the same graphical attributes (color, line width, and so forth) for all features in a layer. Dynamic layers can use different graphical attributes to classify the features in the layer. For example, a dynamic area layer representing sales regions could use different thematic colors to show the quarterly sales performance of each region. A dynamic line layer representing highways could use different line widths to show the classes of roads.