Discrete and Continuous Data

From Wiki.GIS.com

[edit] Discrete Data

Data within a mapped area are discrete when they are found only at certain fixed locations. Features that have distinct boundaries or limits are considered discrete, such as buildings or roads. These are sometimes referred to as discontinuous data. In mapping discrete data can be shown as a point, line, or a polygon.

Discrete data is helpful in showing exact location, perimeter, and length of objects.

[edit] Continuous Data

Continuous data are geographic phenomena that do not have well-defined boundaries and are found everywhere throughout the mapped area. An example of a map containing continuous data would be one displaying temperature measurements across a region.

One of the most common types of continuous data is a topographic map showing elevation on a color scale. Continuous data are often shown in a color scale in order to show change over an extent. In the example of a topographical map, sea level could be shown in white and progress through the gray scale as it gets higher until the highest points on the map appear black.

[edit] References

• Judith A. Tyner, Principles of Map Design, New York: Guilford Press, 2010.