IJGIS special issue on Visual Exploration of Spatial Data

Index to Web Supplements for this issue

Active Legends

For

Interactive Cartographic Animation

PDF Version of Paper

Prof. Michael P. Peterson
Department of Geography / Geology
University of Nebraska at Omaha
Omaha, NE 68182 USA
geolib@unomaha.edu

Disney Studios Animation (1940):

(9.5 MB QuickTime File)

Figure 1. Five frames from the Disney Studios production of the invasion of Poland in 1939. Arrows, representing the German army, are shown encircling the capital of Warsau.

MacChoro II Animations

MacChoro II was written in 1988 and was an early program that implemented an interactive form of cartographic animation. The following are examples of non-temporal cartographic animations produced with the program.

• Generalization Animation - This animation depicts the percent of births to mothers under the age of 20 for the United States. The first frame in the animation is a two-class map and the last frame is a seven class map. The legend is represented as a histogram with bars indicating the number of observations in each category.
• Classification Animation - This animation consists of just four maps each a different classification of the data. The four classification types are standard-deviation, equal interval, quantile and natural breaks.
• Geographic Trend Animation - The last example of non-temporal cartographic animation depicts a spatial trend. The objective of this type of animation is to show the relationship of a series of related variables. The maps show census tract data of age of population for Omaha, Nebraska. Younger people tend to live in the western parts of the city while the older population tends to remain in the eastern parts of the city. The animation depicts this distribution of age groups as a 'wave' between the eastern and western parts of the city.

Temporal animations show change over time and can also be created with the program. An example of a temporal animation is the change in the use of irrigation in Nebraska in the 33 year time span between 1954 and 1987. In the 1950's, irrigation was mostly used in the western counties. During the late 1960's and 1970's, irrigation was expanded in the central part of the state.

Interactive Cartographic Animations implemented with JavaScript:

(JavaScript is implemented in Netscape 3 or higher, Explorer 4 or higher. Clicking on the illustration below will activate the associated map display implemented in JavaScript. Move mouse over active legends to switch frames.)

(683 KB Javascript Mouse-over Mapping Example)

(JavaScript is implemented in Netscape 3 or higher, Explorer 4 or higher. Clicking on the illustration below will activate the associated map display implemented in JavaScript. Move mouse over active legends to switch frames. Move mouse quickly over active legends on the right to implement an interactive animation.)

JavaScript Mapping example of Mortality Statistics in the state of Nebraska