A Method for Incremental Updating Approximations Based on Variable Precision Set-Valued Ordered Information Systems

Set-valued information systems are a general model of single-valued information systems. Set-valued ordered information systems can be defined based on the inclusion relation between attribute values of objects. Firstly, a variable precision set-valued ordered rough set model is proposed in this paper by introducing the variable precision rough set method into set-valued ordered information systems. Next, the definitions of attribute value coarsening and refining are presented. Then the principle of incremental updating dominating classes in variable precision set-valued ordered information systems is discussed. Furthermore, the principle of incremental updating approximations is proposed. Finally, an example is given to explain the proposed methods of incremental updating.