− | '''联合熵Shannon entropy '''的定义是:以比特为单位,对于具有<math>\mathcal X</math>和<math>\mathcal Y</math>的两个离散随机变量函数<math>X</math>和<math>Y</math>'''有<ref name=cover1991>{{cite book |author1=Thomas M. Cover |author2=Joy A. Thomas |title=Elements of Information Theory |publisher=Wiley |location=Hoboken, New Jersey |year= |isbn=0-471-24195-4}}</ref> | + | '''联合熵 '''的定义是:以比特为单位,对于具有<math>\mathcal X</math>和<math>\mathcal Y</math>的两个离散随机变量函数<math>X</math>和<math>Y</math>'''有<ref name=cover1991>{{cite book |author1=Thomas M. Cover |author2=Joy A. Thomas |title=Elements of Information Theory |publisher=Wiley |location=Hoboken, New Jersey |year= |isbn=0-471-24195-4}}</ref> |