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

        enabled_trans = copy(trans_empty_preset)
        for p in current_marking:
            for t in p.ass_trans:
                if t.sub_marking <= current_marking:
                    enabled_trans.add(t)

        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)
Example #2
0
def __search(sync_net, ini, fin, stop, cost_function, skip):
    decorate_transitions_prepostset(sync_net)
    decorate_places_preset_trans(sync_net)

    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

        enabled_trans = set()
        for p in current_marking:
            for t in p.ass_trans:
                if t.sub_marking <= current_marking:
                    enabled_trans.add(t)

        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
Example #3
0
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

        enabled_trans = copy(trans_empty_preset)
        for p in current_marking:
            for t in p.ass_trans:
                if t.sub_marking <= current_marking:
                    enabled_trans.add(t)

        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)