bwd_seq_gen: Calculate the order in which nodes in the tree should be...

In treeHMM: Tree Structured Hidden Markov Model

Description

Tree is a complex graphical model where we can have multiple parents and multiple children for a node. Hence the order in which the tree should be tranversed becomes significant. Backward algorithm is a dynamic programming problem where to calculate the values at a node, we need the values of the children nodes beforehand, which need to be traversed before this node. This algorithm outputs a possible(not unique) order of the traversal of nodes ensuring that the childrens are traversed first before the parents

Usage

bwd_seq_gen(hmm, nlevel = 100)

Arguments

hmm	hmm Object of class List given as output by initHMM
nlevel	No. of levels in the tree, if known. Default is 100

Value

Vector of length "D", where "D" is the number of nodes in the tree

See Also

backward

Examples

tmat = matrix(c(0,0,1,0,0,0,0,1,0,0,0,0,0,1,1,0,0,0,0,0,0,0,0,0,0),
               5,5, byrow= TRUE ) #for "X" (5 nodes) shaped tree
hmmA = initHMM(c("A","B"),list(c("L","R")), tmat) #one feature with two discrete levels "L" and "R"
bt_sq = bwd_seq_gen(hmmA)

treeHMM documentation built on Dec. 16, 2019, 1:38 a.m.