4-3 Reclassification

Reclassification is to reassign new thematic values or codes to units of spatial feature, which will result in merging polygons.

A set of "reclassify attributes", "dissolve the boundaries" and "merge the polygons" are used frequently in aggregating area objects, as already shown in Figure 4.1 (b).

Reclassification is executed in the following cases.

Generalization: reassignment of existing data into smaller number of classes. Generalization will result in a reduction of the level of detail.

Ranking: valuation of attributes based on an evaluation model or table specified by

Reselection :selection of features to be kept and removal of unselected features.

Figure 4.4 shows examples of the above three cases