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Old engine for Continuous Time Bayesian Networks. Superseded by reCTBN. 🐍 https://github.com/madlabunimib/PyCTBN
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PyCTBN/main_package/classes/estimators/structure_estimator.py.bak

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import sys
sys.path.append('../')
import itertools
import json
import typing
import matplotlib.pyplot as plt
import networkx as nx
import numpy as np
from networkx.readwrite import json_graph
from abc import ABC
import abc
import ..utility.cache as ch
import ..structure_graph.conditional_intensity_matrix import ConditionalIntensityMatrix
import ..structure_graph.network_graph import NetworkGraph
import .parameters_estimator import ParametersEstimator
import ..structure_graph.sample_path import SamplePath
from ..structure_graph.structure import Structure
class StructureEstimator(object):
"""Has the task of estimating the network structure given the trajectories in ``samplepath``.
:param sample_path: the _sample_path object containing the trajectories and the real structure
:type sample_path: SamplePath
:_nodes: the nodes labels
:_nodes_vals: the nodes cardinalities
:_nodes_indxs: the nodes indexes
:_complete_graph: the complete directed graph built using the nodes labels in ``_nodes``
"""
def __init__(self, sample_path: SamplePath, known_edges: typing.List = None):
self._sample_path = sample_path
self.nodes = np.array(self._sample_path.structure.nodes_labels)
self.nodes_vals = self._sample_path.structure.nodes_values
self.nodes_indxs = self._sample_path.structure.nodes_indexes
self._removable_edges_matrix = self.
(known_edges)
self.complete_graph = self.build_complete_graph(self._sample_path.structure.nodes_labels)
self.cache = ch.Cache()
def build_removable_edges_matrix(self, known_edges: typing.List):
"""Builds a boolean matrix who shows if a edge could be removed or not, based on prior knowledge given:
:param known_edges: the list of nodes labels
:type known_edges: List
:return: a boolean matrix
:rtype: np.ndarray
"""
tot_vars_count = self._sample_path.total_variables_count
complete_adj_matrix = np.full((tot_vars_count, tot_vars_count), True)
if known_edges:
for edge in known_edges:
i = self._sample_path.structure.get_node_indx(edge[0])
j = self._sample_path.structure.get_node_indx(edge[1])
complete_adj_matrix[i][j] = False
return complete_adj_matrix
@staticmethod
def build_complete_graph(node_ids: typing.List) -> nx.DiGraph:
"""Builds a complete directed graph (no self loops) given the nodes labels in the list ``node_ids``:
:param node_ids: the list of nodes labels
:type node_ids: List
:return: a complete Digraph Object
:rtype: networkx.DiGraph
"""
complete_graph = nx.DiGraph()
complete_graph.add_nodes_from(node_ids)
complete_graph.add_edges_from(itertools.permutations(node_ids, 2))
return complete_graph
def generate_possible_sub_sets_of_size(self, u: typing.List, size: int, parent_label: str):
"""Creates a list containing all possible subsets of the list ``u`` of size ``size``,
that do not contains a the node identified by ``parent_label``.
:param u: the list of nodes
:type u: List
:param size: the size of the subsets
:type size: int
:param parent_label: the node to exclude in the subsets generation
:type parent_label: string
:return: an Iterator Object containing a list of lists
:rtype: Iterator
"""
list_without_test_parent = u[:]
list_without_test_parent.remove(parent_label)
return map(list, itertools.combinations(list_without_test_parent, size))
def save_results(self) -> None:
"""Save the estimated Structure to a .json file in the path where the data are loaded from.
The file is named as the input dataset but the `results_` word is appended to the results file.
"""
res = json_graph.node_link_data(self._complete_graph)
name = self._sample_path._importer.file_path.rsplit('/', 1)[-1]
name = name.split('.', 1)[0]
name += '_' + str(self._sample_path._importer.dataset_id())
name += '.json'
file_name = 'results_' + name
with open(file_name, 'w') as f:
json.dump(res, f)
def remove_diagonal_elements(self, matrix):
m = matrix.shape[0]
strided = np.lib.stride_tricks.as_strided
s0, s1 = matrix.strides
return strided(matrix.ravel()[1:], shape=(m - 1, m), strides=(s0 + s1, s1)).reshape(m, -1)
@abc.abstractmethod
def estimate_structure(self) -> typing.List:
"""Abstract method to estimate the structure
:return: List of estimated edges
:rtype: Typing.List
"""
pass
def adjacency_matrix(self) -> np.ndarray:
"""Converts the estimated structure ``_complete_graph`` to a boolean adjacency matrix representation.
:return: The adjacency matrix of the graph ``_complete_graph``
:rtype: numpy.ndArray
"""
return nx.adj_matrix(self._complete_graph).toarray().astype(bool)
def spurious_edges(self) -> typing.List:
"""Return the spurious edges present in the estimated structure, if a prior net structure is present in
``_sample_path.structure``.
:return: A list containing the spurious edges
:rtype: List
"""
if not self._sample_path.has_prior_net_structure:
raise RuntimeError("Can not compute spurious edges with no prior net structure!")
real_graph = nx.DiGraph()
real_graph.add_nodes_from(self._sample_path.structure.nodes_labels)
real_graph.add_edges_from(self._sample_path.structure.edges)
return nx.difference(real_graph, self._complete_graph).edges
def save_plot_estimated_structure_graph(self) -> None:
"""Plot the estimated structure in a graphical model style.
Spurious edges are colored in red.
"""
graph_to_draw = nx.DiGraph()
spurious_edges = self.spurious_edges()
non_spurious_edges = list(set(self._complete_graph.edges) - set(spurious_edges))
print(non_spurious_edges)
edges_colors = ['red' if edge in spurious_edges else 'black' for edge in self._complete_graph.edges]
graph_to_draw.add_edges_from(spurious_edges)
graph_to_draw.add_edges_from(non_spurious_edges)
pos = nx.spring_layout(graph_to_draw, k=0.5*1/np.sqrt(len(graph_to_draw.nodes())), iterations=50,scale=10)
options = {
"node_size": 2000,
"node_color": "white",
"edgecolors": "black",
'linewidths':2,
"with_labels":True,
"font_size":13,
'connectionstyle': 'arc3, rad = 0.1',
"arrowsize": 15,
"arrowstyle": '<|-',
"width": 1,
"edge_color":edges_colors,
}
nx.draw(graph_to_draw, pos, **options)
ax = plt.gca()
ax.margins(0.20)
plt.axis("off")
name = self._sample_path._importer.file_path.rsplit('/', 1)[-1]
name = name.split('.', 1)[0]
name += '_' + str(self._sample_path._importer.dataset_id())
name += '.png'
plt.savefig(name)
plt.clf()
print("Estimated Structure Plot Saved At: ", os.path.abspath(name))