A New Algorithm for Relative Attribute Reduction in Decision Table

The relative reduction of attributes in decision table is an important topic in the research on rough set theory. It has been proven that computing all the reductions and the optimal (minimal) reduction of decision table is a NP-hard problem. Most of the algorithms are heuristic and the obtained reductions are sub-optimal. A kind of generalized information table is introduced, on the basis of which a criterion of attribute core and relative attribute reduction is provided. A method for calculating core is presented directly. And then, an algorithm for relative attribute reduction based on the generalized information table is designed, which is suitable for not only consistent decision table but also inconsistent decision table.