Similarly, P(H)=PHDP(H) (4.6) p(y) In order to calculate the a posteriori probabilities, it is necessary to know the a priori probabilities. Let P(Ho)=πo P(H)=π1 UESTC 6Similarly, In order to calculate the a posteriori probabilities, it is necessary to know the a priori probabilities. Let 6 UESTC 1 1 1 ( | ) ( ) ( | ) (4.6) ( ) p y H P H P H y p y = 0 0 P(H ) =  1 1 P(H ) = 