Joint decision matrix computation for rules extraction in two classes of decision systems

The new concept of joint decision matrix is defined and a new algorithm for rule extraction is presented based on joint decision matrix in two classes of decision information systems.By putting equivalence matrix of both conditional attribute and decisional attribute into one matrix,it considerably reduces the times of comparison in matrix forming process,which can effectively improve the algorithmic efficiency.The execution procedure is explained by an example.The complexity analysis and some experiment results show that the algorithm is quite effective.