How do I alter display of vector features depending on their attribute values?
The attribute threshold tables may be use to alter attribute of a vector feature depending on some other attribute. For example, attribute threshold tables may be used to change the size of the city marker depending on its population, or change the line width and color of the road depending on its FCC code: interstate highway, state highway, etc. The threshold table may be controlled by a value of the feature attribute as well as the value of the zoom factor. The threshold table may define an absolute value; for numerical attributes it may also define a relative adjustment factor. The us_cities.lif LIF file in the map_data/layers directory of the GLG Map Server Installation provides an example of using attribute threshold tables. Refer to the Configuration Variables: ATTR MAP chapter of the GLG Map Server Reference Manual for more information.
