ChainEventGraphReducer

class cegpy.ChainEventGraphReducer(ceg: ChainEventGraph)

Bases: object

Reduces Chain Event Graphs given certain and/or uncertain evidence.

Parameters:

ceg (ChainEventGraph) – Chain event graph object to reduce.

property certain_edges: List[Tuple[str]]

Returns:

A list of all edges of the ChainEventGraph that have been observed.

certain_edges is a list of edge tuples of the form: [edge_1, edge_2, … edge_n]

Each edge tuple takes the form: (“source_node_name”, “destination_node_name”, “edge_label”)

property uncertain_edges: List[Tuple[str]]

Returns:

A list of sets of edges of the ChainEventGraph which might have occurred.

uncertain_edges is a list of sets of edge tuples of the form: [{(a, b, label), (a, c, label)}, {(x, y, label), (x, z, label)}]

Each edge tuple takes the form: (“source_node_name”, “destination_node_name”, “edge_label”)

property certain_nodes: Set[str]

Returns:

A set of all nodes of the ChainEventGraph that have been observed.

certain_nodes is a set of nodes of the form: {“node_1”, “node_2”, “node_3”, … “node_n”}

property uncertain_nodes: List[Set[str]]

Returns:

A list of sets of nodes of the ChainEventGraph where there is uncertainty which of the nodes in each set happened.

uncertain_nodes is a list of sets of nodes of the form: [{“node_1”, “node_2”}, {“node_3”, “node_4”}, …]

property paths: List[List[Tuple[str]]]

Returns:

A list of all paths through the reduced ChainEventGraph.

property graph: ChainEventGraph

Returns:

The reduced graph once all evidence has been taken into account.

Return type:

ChainEventGraph

clear_all_evidence() → None

Resets the evidence provided.

add_certain_edge(src: str, dst: str, label: str) → None

Specify an edge that has been observed.

Parameters:

• src (str) – Edge source node label

• dst (str) – Edge destination node label

• label (str) – Label of certain edge

remove_certain_edge(src: str, dst: str, label: str) → None

Specify an edge to remove from the certain edges.

Parameters:

• src (str) – Edge source node label

• dst (str) – Edge destination node label

• label (str) – Label of certain edge

add_certain_edge_list(edges: List[Tuple[str]]) → None

Specify a list of edges that have all been observed.

Parameters:

edges (List[Tuple[str]]) – List of edge tuples of the form (“src”, “dst”, “label”)

remove_certain_edge_list(edges: List[Tuple[str]]) → None

Specify a list of edges that in the certain edge list to remove.

Parameters:

edges (List[Tuple[str]]) – List of edge tuples of the form (“src”, “dst”, “label”)

add_uncertain_edge_set(edge_set: Set[Tuple[str]]) → None

Specify a set of edges where one of the edges has occurred, but you are uncertain of which one it is.

Parameters:

edge_set (Set[Tuple[str]]) – Set of edge tuples of the form (“src”, “dst”, “label”)

remove_uncertain_edge_set(edge_set: Set[Tuple[str]]) → None

Specify a set of edges to remove from the uncertain edges.

Parameters:

edge_set (Set[Tuple[str]]) – Set of edge tuples of the form (“src”, “dst”, “label”)

add_uncertain_edge_set_list(edge_sets: List[Set[Tuple[str]]]) → None

Specify a list of sets of edges where one of the edges has occurred, but you are uncertain of which one it is.

Parameters:

edge_set (List[Set[Tuple[str]]]) – List of sets of edge tuples of the form (“src”, “dst”, “label”)

remove_uncertain_edge_set_list(edge_sets: List[Set[Tuple[str]]]) → None

Specify a list of sets of edges to remove from the evidence list.

Parameters:

edge_set (List[Set[Tuple[str]]]) – List of sets of edge tuples of the form (“src”, “dst”, “label”)

add_certain_node(node: str) → None

Specify a node in the graph that has been observed.

Parameters:

node (str) – A node label e.g. “w4”

remove_certain_node(node: str) → None

Specify a node to be removed from the certain nodes list.

Parameters:

node (str) – A node label e.g. “w4”

add_certain_node_set(nodes: Set[str]) → None

Specify a set of nodes that have been observed.

Parameters:

nodes (Set[str]) – A set of node labels e.g. {“w4”, “w8”}

remove_certain_node_set(nodes: Set[str]) → None

Specify a list of nodes to remove from the list of nodes that have been observed.

Parameters:

nodes (Set[str]) – A set of node labels e.g. {“w4”, “w8”}

add_uncertain_node_set(node_set: Set[str]) → None

Specify a set of nodes where one of the nodes has occurred, but you are uncertain of which one it is.

Parameters:

nodes (Set[str]) – A set of node labels e.g. {“w4”, “w8”}

remove_uncertain_node_set(node_set: Set[str]) → None

Specify a set of nodes to be removed from the uncertain nodes set list.

Parameters:

nodes (Set[str]) – A set of node labels e.g. {“w4”, “w8”}

add_uncertain_node_set_list(node_sets: List[Set[str]]) → None

Specify a list of sets of nodes where in each set, one of the nodes has occurred, but you are uncertain of which one it is.

Parameters:

nodes (List[Set[str]]) – A collection of sets of uncertain nodes.

remove_uncertain_node_set_list(node_sets: List[Set[str]]) → None

Specify a list of sets nodes to remove from the list of uncertain sets of nodes.

Parameters:

nodes (List[Set[str]]) – A collection of sets of uncertain nodes.