Exemplo n.º 1
0
def individual_nudge(old_X: dit.Distribution,
                     eps: float = 0.01,
                     rvs_other=None) -> dit.Distribution:
    mask = old_X._mask
    base = old_X.get_base()
    if old_X.outcome_length() == 1:
        return global_nudge(old_X, eps)
    outcomes = old_X.outcomes
    rv_names = old_X.get_rv_names()

    if rvs_other == None:
        rvs = old_X.get_rv_names()
        rvs_other = np.random.choice(rvs, len(rvs) - 1, replace=False)

    X_other, Xi_given_Xother = old_X.condition_on(rvs_other)
    nudge_size = len(Xi_given_Xother[0])

    if base == 'linear':
        nudge = generate_nudge(nudge_size, eps / len(Xi_given_Xother))
        for Xi in Xi_given_Xother:
            perform_nudge(Xi, nudge)
    else:
        nudge, sign = generate_log_nudge(nudge_size, eps)
        for Xi in Xi_given_Xother:
            perform_log_nudge(Xi, nudge, sign)
    new_X = dit.joint_from_factors(X_other, Xi_given_Xother).copy(base)
    #add back any missing outcomes
    dct = {o: new_X[o] if o in new_X.outcomes else 0.0 for o in outcomes}
    #print(outcomes, dct)
    new_X = dit.Distribution(dct)
    new_X.set_rv_names(rv_names)
    new_X.make_dense()
    new_X._mask = mask
    return new_X
Exemplo n.º 2
0
def max_individual(input: dit.Distribution,
                   conditional: np.ndarray,
                   eps: float = 0.01,
                   minimal_entropy_idx=None):
    rvs = input.get_rv_names()
    conditional = conditional / conditional.sum()
    states = len(input.alphabet[0])
    if not minimal_entropy_idx == 0 and not minimal_entropy_idx:
        minimal_entropy_idx = np.argmin([
            entropy(input.marginal([rv], rv_mode='indices').pmf)
            for rv in range(len(rvs))
        ])

    non_minimal_rvs = rvs[:minimal_entropy_idx] + rvs[minimal_entropy_idx + 1:]
    non_minimal_marginal, minimal_conditional = input.condition_on(
        non_minimal_rvs)
    [d.make_dense() for d in minimal_conditional]
    # minimal_conditional = np.stack([d.pmf for d in minimal_conditional])
    # print("minimal_conditional:",minimal_conditional)
    indiv_shape = (len(minimal_conditional), len(minimal_conditional[0]))

    # minimal_conditional = minimal_conditional.flatten()
    nudge_vector = np.zeros(indiv_shape)
    rotated_conditional = R(conditional, minimal_entropy_idx, len(rvs), states)
    total_max_impact = 0
    # print(len(rvs), (eps / 2)/len(minimal_conditional))
    for i, mc_dist in enumerate(minimal_conditional):

        rows = rotated_conditional[i * states:(i + 1) * states, :]

        max_impact = 0
        for allignment in itertools.product(
            [-1, 1], repeat=rotated_conditional.shape[1]):
            allignment = np.array(allignment)
            if np.all(allignment == 1) or np.all(allignment == -1):
                continue
            scores = np.sum(allignment * rows, axis=1)

            # Add rotation of scores so that scores are well aligned.
            # Weigh scores using the non_minimal_marginal

            vector, impact = find_max_impact(scores, mc_dist.pmf, (eps / 2) /
                                             len(minimal_conditional))
            if impact > max_impact:
                nudge_vector[i, :] = vector
                max_impact = impact
        total_max_impact += max_impact
    return nudge_vector, total_max_impact, minimal_entropy_idx
Exemplo n.º 3
0
def get_marginals(
        d: dit.Distribution) -> (dit.Distribution, List[dit.Distribution]):
    rvs = d.get_rv_names()[:-1]  #everything except the output
    return d.condition_on(rvs)