Comparison with the Three Types of Discernibility Matrix
三种差别矩阵的比较

The discernibility matrix is an important concept in the rough set theory and is the basis of computing the core and reducts of decision tables. Inconsistent data in decision tables results in the different definitions of discernibility matrix. In this paper, the relationship between inconsistent deision tables and consistent decision tables is analyzed, and the method whieh ean convert inconsistent deeision tables into consistent deeision tables is presented. The equivalent definition about any two types of diseemibility matrix is proposed. Based on these results above, the relationship of three types of diseemibility matrix is diseussed and some properties are proved. The properties show that the three types of discernibility matrix can be unified based on the converting method and the equivalent definition, so one can use only method to construet the diseernibility matrix in praetiee.