def __calculate_heuristics(prev_h, prev_x, m0, index, corresp, t0, sync_net, incidence_matrix,
fin_vec, cost_vec, a_matrix, g_matrix, h_cvx, variant, use_cvxopt=False,
compute_exact_heu=False):
"""
Calculate the heuristics
Returns
---------------
h
Heuristic value
x
Solution
"""
m, t = get_corresp_marking_and_trans(m0, index, corresp, t0)
h = 0
x = None
if compute_exact_heu or t is None:
h, x = utils.__compute_exact_heuristic_new_version(sync_net, a_matrix, h_cvx, g_matrix, cost_vec,
incidence_matrix, m, fin_vec, variant, use_cvxopt=use_cvxopt)
trustable = True
else:
h, x = utils.__derive_heuristic(incidence_matrix, cost_vec, prev_x, t, prev_h)
trustable = utils.__trust_solution(x)
return h, x, trustable
def __update_heu_dict(heu_dict, heu_max_ind_dict, mm, index, h, x,
firing_sequence, incidence_matrix, cost_vec):
"""
Updates the heuristics dictionary on the new marking, storing the information about the heuristics
and the vector
"""
x = copy(x)
__update_heu_dict_specific_point(heu_dict, heu_max_ind_dict, mm, index, h,
x)
firing_sequence = list(firing_sequence)
while firing_sequence:
t = firing_sequence.pop(0)
h, x = utils.__derive_heuristic(incidence_matrix, cost_vec, x, t, h)
mm = semantics.weak_execute(t, mm)
__update_heu_dict_specific_point(heu_dict, heu_max_ind_dict, mm, index,
h, x)
def __search(sync_net, ini, fin, stop, cost_function, skip, max_trace_length):
from pm4py.objects.petri.utils import decorate_places_preset_trans, decorate_transitions_prepostset
decorate_transitions_prepostset(sync_net)
decorate_places_preset_trans(sync_net)
incidence_matrix = petri.incidence_matrix.construct(sync_net)
ini_vec, fin_vec, cost_vec = utils.__vectorize_initial_final_cost(
incidence_matrix, ini, fin, cost_function)
closed = set()
a_matrix = np.asmatrix(incidence_matrix.a_matrix).astype(np.float64)
g_matrix = -np.eye(len(sync_net.transitions))
h_cvx = np.matrix(np.zeros(len(sync_net.transitions))).transpose()
cost_vec = [x * 1.0 for x in cost_vec]
use_cvxopt = False
if lp_solver_factory.DEFAULT_LP_SOLVER_VARIANT == lp_solver_factory.CVXOPT_SOLVER_CUSTOM_ALIGN or lp_solver_factory.DEFAULT_LP_SOLVER_VARIANT == lp_solver_factory.CVXOPT_SOLVER_CUSTOM_ALIGN_ILP:
use_cvxopt = True
if use_cvxopt:
# not available in the latest version of PM4Py
from cvxopt import matrix
a_matrix = matrix(a_matrix)
g_matrix = matrix(g_matrix)
h_cvx = matrix(h_cvx)
cost_vec = matrix(cost_vec)
h, x = utils.__compute_exact_heuristic_new_version(
sync_net,
a_matrix,
h_cvx,
g_matrix,
cost_vec,
incidence_matrix,
ini,
fin_vec,
lp_solver_factory.DEFAULT_LP_SOLVER_VARIANT,
use_cvxopt=use_cvxopt)
# heuristics need to be adapted for prefix alignments
# here we make the heuristics way less powerful
h = h / (max_trace_length + 1.0)
ini_state = SearchTuple(0 + h, 0, h, ini, None, None, x, True)
open_set = [ini_state]
heapq.heapify(open_set)
visited = 0
queued = 0
traversed = 0
while not len(open_set) == 0:
curr = heapq.heappop(open_set)
current_marking = curr.m
# 11/10/2019 (optimization Y, that was optimization X,
# but with the good reasons this way): avoid checking markings in the cycle using
# the __get_alt function, but check them 'on the road'
already_closed = current_marking in closed
if already_closed:
continue
while not curr.trust:
h, x = utils.__compute_exact_heuristic_new_version(
sync_net,
a_matrix,
h_cvx,
g_matrix,
cost_vec,
incidence_matrix,
curr.m,
fin_vec,
lp_solver_factory.DEFAULT_LP_SOLVER_VARIANT,
use_cvxopt=use_cvxopt)
# heuristics need to be adapted for prefix alignments
# here we make the heuristics way less powerful
h = h / (max_trace_length + 1.0)
# 11/10/19: shall not a state for which we compute the exact heuristics be
# by nature a trusted solution?
tp = SearchTuple(curr.g + h, curr.g, h, curr.m, curr.p, curr.t, x,
True)
# 11/10/2019 (optimization ZA) heappushpop is slightly more efficient than pushing
# and popping separately
curr = heapq.heappushpop(open_set, tp)
current_marking = curr.m
# max allowed heuristics value (27/10/2019, due to the numerical instability of some of our solvers)
if curr.h > lp_solver_factory.MAX_ALLOWED_HEURISTICS:
continue
# 12/10/2019: do it again, since the marking could be changed
already_closed = current_marking in closed
if already_closed:
continue
# 12/10/2019: the current marking can be equal to the final marking only if the heuristics
# (underestimation of the remaining cost) is 0. Low-hanging fruits
enab_trans = [
x for x in petri.semantics.enabled_transitions(
sync_net, current_marking)
]
if stop <= current_marking:
#print(utils.__reconstruct_alignment(curr, visited, queued, traversed))
enab_trans = [
x for x in sync_net.transitions
if x.sub_marking <= current_marking
]
return current_marking
closed.add(current_marking)
visited += 1
possible_enabling_transitions = set()
for p in current_marking:
for t in p.ass_trans:
possible_enabling_transitions.add(t)
enabled_trans = [
t for t in possible_enabling_transitions
if t.sub_marking <= current_marking
]
trans_to_visit_with_cost = [
(t, cost_function[t]) for t in enabled_trans
if not (curr.t is not None and utils.__is_log_move(curr.t, skip)
and utils.__is_model_move(t, skip))
]
for t, cost in trans_to_visit_with_cost:
traversed += 1
new_marking = utils.add_markings(current_marking, t.add_marking)
if new_marking in closed:
continue
g = curr.g + cost
queued += 1
h, x = utils.__derive_heuristic(incidence_matrix, cost_vec, curr.x,
t, curr.h)
# heuristics need to be adapted for prefix alignments
# here we make the heuristics way less powerful
h = h / (max_trace_length + 1.0)
trustable = utils.__trust_solution(x)
new_f = g + h
tp = SearchTuple(new_f, g, h, new_marking, curr, t, x, trustable)
heapq.heappush(open_set, tp)
def __search(sync_net,
ini,
fin,
cost_function,
skip,
ret_tuple_as_trans_desc=False,
max_align_time_trace=sys.maxsize):
start_time = time.time()
decorate_transitions_prepostset(sync_net)
decorate_places_preset_trans(sync_net)
incidence_matrix = inc_mat_construct(sync_net)
ini_vec, fin_vec, cost_vec = utils.__vectorize_initial_final_cost(
incidence_matrix, ini, fin, cost_function)
closed = set()
a_matrix = np.asmatrix(incidence_matrix.a_matrix).astype(np.float64)
g_matrix = -np.eye(len(sync_net.transitions))
h_cvx = np.matrix(np.zeros(len(sync_net.transitions))).transpose()
cost_vec = [x * 1.0 for x in cost_vec]
use_cvxopt = False
if lp_solver.DEFAULT_LP_SOLVER_VARIANT == lp_solver.CVXOPT_SOLVER_CUSTOM_ALIGN or lp_solver.DEFAULT_LP_SOLVER_VARIANT == lp_solver.CVXOPT_SOLVER_CUSTOM_ALIGN_ILP:
use_cvxopt = True
if use_cvxopt:
# not available in the latest version of PM4Py
from cvxopt import matrix
a_matrix = matrix(a_matrix)
g_matrix = matrix(g_matrix)
h_cvx = matrix(h_cvx)
cost_vec = matrix(cost_vec)
h, x = utils.__compute_exact_heuristic_new_version(
sync_net,
a_matrix,
h_cvx,
g_matrix,
cost_vec,
incidence_matrix,
ini,
fin_vec,
lp_solver.DEFAULT_LP_SOLVER_VARIANT,
use_cvxopt=use_cvxopt)
ini_state = utils.SearchTuple(0 + h, 0, h, ini, None, None, x, True)
open_set = [ini_state]
heapq.heapify(open_set)
visited = 0
queued = 0
traversed = 0
lp_solved = 1
trans_empty_preset = set(t for t in sync_net.transitions
if len(t.in_arcs) == 0)
while not len(open_set) == 0:
if (time.time() - start_time) > max_align_time_trace:
return None
curr = heapq.heappop(open_set)
current_marking = curr.m
while not curr.trust:
if (time.time() - start_time) > max_align_time_trace:
return None
already_closed = current_marking in closed
if already_closed:
curr = heapq.heappop(open_set)
current_marking = curr.m
continue
h, x = utils.__compute_exact_heuristic_new_version(
sync_net,
a_matrix,
h_cvx,
g_matrix,
cost_vec,
incidence_matrix,
curr.m,
fin_vec,
lp_solver.DEFAULT_LP_SOLVER_VARIANT,
use_cvxopt=use_cvxopt)
lp_solved += 1
# 11/10/19: shall not a state for which we compute the exact heuristics be
# by nature a trusted solution?
tp = utils.SearchTuple(curr.g + h, curr.g, h, curr.m, curr.p,
curr.t, x, True)
# 11/10/2019 (optimization ZA) heappushpop is slightly more efficient than pushing
# and popping separately
curr = heapq.heappushpop(open_set, tp)
current_marking = curr.m
# max allowed heuristics value (27/10/2019, due to the numerical instability of some of our solvers)
if curr.h > lp_solver.MAX_ALLOWED_HEURISTICS:
continue
# 12/10/2019: do it again, since the marking could be changed
already_closed = current_marking in closed
if already_closed:
continue
# 12/10/2019: the current marking can be equal to the final marking only if the heuristics
# (underestimation of the remaining cost) is 0. Low-hanging fruits
if curr.h < 0.01:
if current_marking == fin:
return utils.__reconstruct_alignment(
curr,
visited,
queued,
traversed,
ret_tuple_as_trans_desc=ret_tuple_as_trans_desc,
lp_solved=lp_solved)
closed.add(current_marking)
visited += 1
possible_enabling_transitions = copy(trans_empty_preset)
for p in current_marking:
for t in p.ass_trans:
possible_enabling_transitions.add(t)
enabled_trans = [
t for t in possible_enabling_transitions
if t.sub_marking <= current_marking
]
trans_to_visit_with_cost = [
(t, cost_function[t]) for t in enabled_trans
if not (t is not None and utils.__is_log_move(t, skip)
and utils.__is_model_move(t, skip))
]
for t, cost in trans_to_visit_with_cost:
traversed += 1
new_marking = utils.add_markings(current_marking, t.add_marking)
if new_marking in closed:
continue
g = curr.g + cost
queued += 1
h, x = utils.__derive_heuristic(incidence_matrix, cost_vec, curr.x,
t, curr.h)
trustable = utils.__trust_solution(x)
new_f = g + h
tp = utils.SearchTuple(new_f, g, h, new_marking, curr, t, x,
trustable)
heapq.heappush(open_set, tp)
def __search(sync_net,
ini,
fin,
cost_function,
skip,
ret_tuple_as_trans_desc=False,
max_align_time_trace=sys.maxsize):
start_time = time.time()
decorate_transitions_prepostset(sync_net)
decorate_places_preset_trans(sync_net)
incidence_matrix = inc_mat_construct(sync_net)
ini_vec, fin_vec, cost_vec = utils.__vectorize_initial_final_cost(
incidence_matrix, ini, fin, cost_function)
closed = set()
heu_dict = {}
heu_max_ind_dict = {}
mtcgt_dict = {}
parameters = {}
parameters[marking_equation.Parameters.FULL_BOOTSTRAP_REQUIRED] = False
parameters[marking_equation.Parameters.INCIDENCE_MATRIX] = incidence_matrix
parameters[marking_equation.Parameters.COSTS] = cost_function
visited = 0
queued = 0
traversed = 0
me = marking_equation.build(sync_net, ini, fin, parameters=parameters)
h, x = me.solve()
lp_solved = 1
# try to see if the firing sequence is already fine
firing_sequence, reach_fm, explained_events = me.get_firing_sequence(x)
if reach_fm:
return __reconstruct_alignment(
firing_sequence,
h,
visited,
queued,
traversed,
ret_tuple_as_trans_desc=ret_tuple_as_trans_desc,
lp_solved=lp_solved)
mm, index = __get_model_marking_and_index(ini)
__update_heu_dict(heu_dict, heu_max_ind_dict, mm, index, h, x,
firing_sequence, incidence_matrix, cost_vec)
ini_state = utils.TweakedSearchTuple(0 + h, 0, h, ini, None, None, x, True,
False)
open_set = [ini_state]
heapq.heapify(open_set)
trans_empty_preset = set(t for t in sync_net.transitions
if len(t.in_arcs) == 0)
while not len(open_set) == 0:
if (time.time() - start_time) > max_align_time_trace:
return None
curr = heapq.heappop(open_set)
current_marking = curr.m
while not curr.trust:
if (time.time() - start_time) > max_align_time_trace:
return None
already_closed = current_marking in closed
if already_closed:
curr = heapq.heappop(open_set)
current_marking = curr.m
continue
if curr.t not in mtcgt_dict:
lp_solved += 1
mtcgt = __min_total_cost_given_trans(me, ini, incidence_matrix,
curr.t)
mtcgt_dict[curr.t] = mtcgt
else:
mtcgt = mtcgt_dict[curr.t]
h1 = max(mtcgt - curr.g, 0)
if h1 > curr.h:
tp = utils.TweakedSearchTuple(curr.g + h1, curr.g, h1, curr.m,
curr.p, curr.t, curr.x, False,
False)
curr = heapq.heappushpop(open_set, tp)
current_marking = curr.m
continue
mm, index = __get_model_marking_and_index(curr.m)
h2, x2, trust2 = __get_heu_from_dict(heu_dict, heu_max_ind_dict,
mm, index)
if h2 is not None and h2 > curr.h:
tp = utils.TweakedSearchTuple(curr.g + h2, curr.g, h2, curr.m,
curr.p, curr.t, x2, trust2,
False)
curr = heapq.heappushpop(open_set, tp)
current_marking = curr.m
continue
me.change_ini_vec(curr.m)
h, x = me.solve()
__update_heu_dict_specific_point(heu_dict, heu_max_ind_dict, mm,
index, h, x)
lp_solved += 1
tp = utils.TweakedSearchTuple(curr.g + h, curr.g, h, curr.m,
curr.p, curr.t, x, True, True)
curr = heapq.heappushpop(open_set, tp)
current_marking = curr.m
already_closed = current_marking in closed
if already_closed:
continue
if curr.h < 0.01:
if current_marking == fin:
trans_list = __transitions_list_from_state(curr)
return __reconstruct_alignment(
trans_list,
curr.f,
visited,
queued,
traversed,
ret_tuple_as_trans_desc=ret_tuple_as_trans_desc,
lp_solved=lp_solved)
if curr.virgin:
# try to see if the firing sequence is already fine
firing_sequence, reach_fm, explained_events = me.get_firing_sequence(
curr.x)
if reach_fm:
trans_list = __transitions_list_from_state(curr) + list(
firing_sequence)
return __reconstruct_alignment(
trans_list,
curr.f,
visited,
queued,
traversed,
ret_tuple_as_trans_desc=ret_tuple_as_trans_desc,
lp_solved=lp_solved)
mm, index = __get_model_marking_and_index(curr.m)
__update_heu_dict(heu_dict, heu_max_ind_dict, mm, index, h, x,
firing_sequence, incidence_matrix, cost_vec)
closed.add(current_marking)
visited += 1
possible_enabling_transitions = copy(trans_empty_preset)
for p in current_marking:
for t in p.ass_trans:
possible_enabling_transitions.add(t)
enabled_trans = [
t for t in possible_enabling_transitions
if t.sub_marking <= current_marking
]
trans_to_visit_with_cost = [
(t, cost_function[t]) for t in enabled_trans
if not (t is not None and utils.__is_log_move(t, skip)
and utils.__is_model_move(t, skip))
]
for t, cost in trans_to_visit_with_cost:
traversed += 1
new_marking = utils.add_markings(current_marking, t.add_marking)
if new_marking in closed:
continue
g = curr.g + cost
queued += 1
h, x = utils.__derive_heuristic(incidence_matrix, cost_vec, curr.x,
t, curr.h)
trust = utils.__trust_solution(x)
mm, index = __get_model_marking_and_index(new_marking)
if not trust:
h2, x2, trust2 = __get_heu_from_dict(heu_dict,
heu_max_ind_dict, mm,
index)
if h2 is not None and (h2 > h or trust2):
h = h2
x = x2
trust = trust2
else:
__update_heu_dict_specific_point(heu_dict, heu_max_ind_dict,
mm, index, h, x)
new_f = g + h
tp = utils.TweakedSearchTuple(new_f, g, h, new_marking, curr, t, x,
trust, False)
heapq.heappush(open_set, tp)
