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
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
# 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.DEFAULT_LP_SOLVER_VARIANT,
use_cvxopt=use_cvxopt)
# 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)
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, stop, cost_function, skip):
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()
ini_state = utils.SearchTuple(0, 0, 0, ini, None, None, None, True)
open_set = [ini_state]
heapq.heapify(open_set)
visited = 0
queued = 0
traversed = 0
# return all the prefix markings of the optimal alignments as set
ret_markings = None
# keep track of the optimal cost of an alignment (to trim search when needed)
optimal_cost = None
while not len(open_set) == 0:
curr = heapq.heappop(open_set)
current_marking = curr.m
# trim alignments when we already reached an optimal alignment and the
# current cost is greater than the optimal cost
if optimal_cost is not None and curr.f > optimal_cost:
break
already_closed = current_marking in closed
if already_closed:
continue
if stop <= current_marking:
# add the current marking to the set
# of returned markings
if ret_markings is None:
ret_markings = set()
ret_markings.add(current_marking)
# close the marking
closed.add(current_marking)
# set the optimal cost
optimal_cost = curr.f
continue
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 (t is None or utils.__is_log_move(t, skip) or (
utils.__is_model_move(t, skip) and not t.label[1] is None))
]
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
new_f = g
tp = utils.SearchTuple(new_f, g, 0, new_marking, curr, t, None,
True)
heapq.heappush(open_set, tp)
return ret_markings
