Automatic Legends for Proportional Symbol Maps
This Java applet demonstrates self-adjusting legends for proportional symbol maps. Legends only display intermediate symbols for round values (for example 100, 250, 500, 1000, 2500, etc.). The legend will always display a set of appropriate intermediate symbols, even when the minimum and the maximum values are very large or very small.
Paper with more details.
Parameters
- The Maximum and the Minimum value define the range of the legend. Fractional positive numbers can be entered.
- The Size slider adjusts the legend size.
- Type Size controls the size of the text labels.
- The Distance slider defines the minimum distance between two symbols. The minimum distance is the value selected with this slider, multiplied with the type size. If two intermediate symbols are closer than this distance, the smaller symbol is removed. The default value is 1.25, which will not have to be changed in most cases.
- Intermediate symbols will be inserted at multiples of values entered in the Breaks field. Example: A break value of 5 will place symbols at 0.5, 5, 50, 500, etc. The symbols actually displayed also depend on the value specified by the Distance slider. The default break values are
5 2.5 1. These values will not have to be changed in most cases. - Use the Export button to generate SVG formatted output that can be read with Adobe Illustrator and many other vector graphics programs.
If the applet does not load, please install Java or view a screenshot of the applet. Reload the page to revert to default values. The Java source code of this applet is available here (Netbeans 6.5 project).
Applet version of 14 April 2009, © by Bernhard Jenny, Institute of Cartography, ETH Zurich.