不完备信息系统的程度属性约简方法

hroughout the analysis of the compatible relationship between the attributes, the change of knowledge granularity and attribute importance, by means of the thinking of variable precision rough set model, the rate of relative error reduction( ) is defined. Based on it, the paper proposes the concept and method of degree attribute reduction and gives a correspondent algorithm. By the analysis of the time complexity of the algorithm, the time complexity of the algorithm in the paper is .By example, the degree attribute reduction method is effective. The degree attribute reduction method in Incomplete information systems is a kind of attribute reduction method in essence to maintain the granularity to a certain extent deleting a number of relatively unimportant or irrelevant properties. The one can extract useful information in information systems in accordance with the user demands and simplify information systems to a greater degree.