GIS: The Essentials - Sampling Spatial Units for Agricultural Surveys - page 56

Input coverage Clip coverage Output coverage

Fig. 3.4 Clip

Input coverage Erase coverage Output coverage

Fig. 3.5 Erase

Input coverage Split coverage Output coverage

Fig. 3.6 Split

are two types of buffers: constant and variable width buffers. Both types can be
generated for a set of coverage features, based on each feature attribute values.
Furthermore, a GIS can select features from the data (i.e., feature selection). For
example, all the trees that have a specific characteristic can be selected from a
forest map.
Finally, feature classification identifies a set of features as belonging to a group
and defines patterns. Note that some form of classification function is provided in
every GIS.