From a5a703c11d4c31a70be6d401449892f0dbb662da Mon Sep 17 00:00:00 2001
From: wkaiz
diff --git a/bayes-nets/elimination.md b/bayes-nets/elimination.md index cac521b..bb599cc 100644 --- a/bayes-nets/elimination.md +++ b/bayes-nets/elimination.md @@ -22,11 +22,11 @@ An alternate approach is to eliminate hidden variables one by one. To **eliminat A **factor** is defined simply as an _unnormalized probability_. At all points during variable elimination, each factor will be proportional to the probability it corresponds to, but the underlying distribution for each factor won't necessarily sum to 1 as a probability distribution should. The pseudocode for variable elimination is here: -![Variable Elimination](../assets/images/VarElim.png) + Let's make these ideas more concrete with an example. Suppose we have a model as shown below, where $$T$$, $$C$$, $$S$$, and $$E$$ can take on binary values. Here, $$T$$ represents the chance that an adventurer takes a treasure, $$C$$ represents the chance that a cage falls on the adventurer given that they take the treasure, $$S$$ represents the chance that snakes are released if an adventurer takes the treasure, and $$E$$ represents the chance that the adventurer escapes given information about the status of the cage and snakes. -![Variable Elimination](../assets/images/another_bayes_nets.png) +
diff --git a/bayes-nets/structure.md b/bayes-nets/structure.md index 3962564..7a110a6 100644 --- a/bayes-nets/structure.md +++ b/bayes-nets/structure.md @@ -13,11 +13,11 @@ In this class, we will refer to two rules for Bayes Net independences that can b - **Each node is conditionally independent of all its ancestor nodes (non-descendants) in the graph, given all of its parents.** - ![Parents](../assets/images/parents.png) + - **Each node is conditionally independent of all other variables given its Markov blanket.** A variable’s Markov blanket consists of parents, children, and children’s other parents. - ![Markov Blanket](../assets/images/blanket.png) + Using these tools, we can return to the assertion in the previous section: that we can get the joint distribution of all variables by joining the CPTs of the Bayes Net. @@ -28,7 +28,7 @@ This relation between the joint distribution and the CPTs of the Bayes net works Let's revisit the previous example. We have the CPTs $$P(B)$$ , $$P(E)$$ , $$P(A |B,E)$$ , $$P(J | A)$$ and $$P(M | A)$$ , and the following graph: -![Basic Bayes Net Examples](../assets/images/basic_bayes_nets.png) + For this Bayes net, we are trying to prove the following relation: