New Computation for Rules Extraction Based on Block Matrix

As a new mathematical tool to deal with uncertainty, rough sets theory has been successfully applied in many field such as pattern recognition, data reduction and so on. Because the limitations of discernible matrix and equivalence matrix for rules extraction, a new definition of block equivalence matrix and its strategy of divide and conquer for rules extraction in information system have been put forward based on rules extraction of equivalence matrix; According to equal division principle, the process of transforming rules extraction in information system to parallel rules extraction in agents corresponding to the multiple subsystems after division effectively solves the problem of rules extraction in information system. Complexity analysis shows that the algorithm is more efficient than those existing algorithms. An example is used to illustrate the efficiency of the new algorithm based on matrix block.