Exemple #1
0
    def read_bif(path, is_quantum):
        """
        Reads a bif file using our stand-alone class BifTool and returns a
        BayesNet. bif and dot files complement each other. bif: graphical
        info No, pot info Yes. dot: graphical info Yes, pot info No. By pots
        I mean potentials, the transition matrices of the nodes. (aka CPTs,
        etc.)

        Parameters
        ----------
        path : str
        is_quantum : bool

        Returns
        -------
        BayesNet

        """

        bt = BifTool(is_quantum)
        bt.read_bif(path)
        nodes = set()
        name_to_nd = {}
        for k, nd_name in enumerate(bt.nd_sizes.keys()):
            node = BayesNode(k, nd_name)
            node.state_names = bt.states[nd_name]
            node.size = len(node.state_names)
            node.forget_all_evidence()
            nodes |= {node}
            name_to_nd[nd_name] = node
        for nd_name, pa_name_list in bt.parents.items():
            node = name_to_nd[nd_name]
            for pa_name in pa_name_list:
                pa = name_to_nd[pa_name]
                node.add_parent(pa)

        for nd_name, parent_names in bt.parents.items():
            node = name_to_nd[nd_name]
            num_pa = len(parent_names)
            parents = [name_to_nd[pa_name] for pa_name in parent_names]
            if num_pa == 0:
                node.potential = DiscreteUniPot(is_quantum, node)
            else:
                node.potential = DiscreteCondPot(
                    is_quantum, parents + [node])
            node.potential.pot_arr = bt.pot_arrays[nd_name]

        return BayesNet(nodes)