usm.py 文件源码

def unfringe(self, alpha=0.05):
        """
        This method decides whether to expand the suffix trie onto the fringe.
        It does this by constructing a distribution of the utilities of all the current states and from one
        that includes the current state as well fringe nodes that are on the unofficial leaf of the tree.
        If the two distributions are sufficiently different then the state space is expanded to include all leaf nodes
        currently in the tree. The distribution comparison is performed using a KS test.
        """
        all_leaves = self.tree_leaves()
        all_leaves_dist = list(map(lambda leaf: self.utility(leaf), all_leaves))
        print(all_leaves_dist)
        current_leaves = self.get_states()
        current_dist = list(map(lambda leaf: self.utility(leaf), current_leaves))
        print(current_dist)
        D, p_value = test_result = ks_2samp(all_leaves_dist, current_dist)
        print(D)
        print(p_value)
        if p_value < alpha or alpha < D:
            for leaf in all_leaves:
                if leaf.is_fringe:
                    leaf.set_fringe(False)
                    self._correct_fringe(leaf)
            return True
        else:
            return False