Python numpy.logaddexp方法代码示例

# 需要导入模块: import numpy [as 别名]
# 或者: from numpy import logaddexp [as 别名]
def test_NotImplemented_not_returned(self):
        # See gh-5964 and gh-2091. Some of these functions are not operator
        # related and were fixed for other reasons in the past.
        binary_funcs = [
            np.power, np.add, np.subtract, np.multiply, np.divide,
            np.true_divide, np.floor_divide, np.bitwise_and, np.bitwise_or,
            np.bitwise_xor, np.left_shift, np.right_shift, np.fmax,
            np.fmin, np.fmod, np.hypot, np.logaddexp, np.logaddexp2,
            np.logical_and, np.logical_or, np.logical_xor, np.maximum,
            np.minimum, np.mod,
            np.greater, np.greater_equal, np.less, np.less_equal,
            np.equal, np.not_equal]

        a = np.array('1')
        b = 1
        c = np.array([1., 2.])
        for f in binary_funcs:
            assert_raises(TypeError, f, a, b)
            assert_raises(TypeError, f, c, a) 

# 需要导入模块: import numpy [as 别名]
# 或者: from numpy import logaddexp [as 别名]
def test_NotImplemented_not_returned(self):
        # See gh-5964 and gh-2091. Some of these functions are not operator
        # related and were fixed for other reasons in the past.
        binary_funcs = [
            np.power, np.add, np.subtract, np.multiply, np.divide,
            np.true_divide, np.floor_divide, np.bitwise_and, np.bitwise_or,
            np.bitwise_xor, np.left_shift, np.right_shift, np.fmax,
            np.fmin, np.fmod, np.hypot, np.logaddexp, np.logaddexp2,
            np.logical_and, np.logical_or, np.logical_xor, np.maximum,
            np.minimum, np.mod
            ]

        # These functions still return NotImplemented. Will be fixed in
        # future.
        # bad = [np.greater, np.greater_equal, np.less, np.less_equal, np.not_equal]

        a = np.array('1')
        b = 1
        for f in binary_funcs:
            assert_raises(TypeError, f, a, b) 

# 需要导入模块: import numpy [as 别名]
# 或者: from numpy import logaddexp [as 别名]
def _parallel_predict_log_proba(estimators, estimators_features, X, n_classes):
    """Private function used to compute log probabilities within a job."""
    n_samples = X.shape[0]
    log_proba = np.empty((n_samples, n_classes))
    log_proba.fill(-np.inf)
    all_classes = np.arange(n_classes, dtype=np.int)

    for estimator, features in zip(estimators, estimators_features):
        log_proba_estimator = estimator.predict_log_proba(X[:, features])

        if n_classes == len(estimator.classes_):
            log_proba = np.logaddexp(log_proba, log_proba_estimator)

        else:
            log_proba[:, estimator.classes_] = np.logaddexp(
                log_proba[:, estimator.classes_],
                log_proba_estimator[:, range(len(estimator.classes_))])

            missing = np.setdiff1d(all_classes, estimator.classes_)
            log_proba[:, missing] = np.logaddexp(log_proba[:, missing],
                                                 -np.inf)

    return log_proba 

# 需要导入模块: import numpy [as 别名]
# 或者: from numpy import logaddexp [as 别名]
def __call__(self, y, raw_predictions, sample_weight=None):
        """Compute the deviance (= 2 * negative log-likelihood).

        Parameters
        ----------
        y : 1d array, shape (n_samples,)
            True labels.

        raw_predictions : 2d array, shape (n_samples, K)
            The raw predictions (i.e. values from the tree leaves) of the
            tree ensemble.

        sample_weight : 1d array , shape (n_samples,), optional
            Sample weights.
        """
        # logaddexp(0, v) == log(1.0 + exp(v))
        raw_predictions = raw_predictions.ravel()
        if sample_weight is None:
            return -2 * np.mean((y * raw_predictions) -
                                np.logaddexp(0, raw_predictions))
        else:
            return (-2 / sample_weight.sum() * np.sum(
                sample_weight * ((y * raw_predictions) -
                                 np.logaddexp(0, raw_predictions)))) 

# 需要导入模块: import numpy [as 别名]
# 或者: from numpy import logaddexp [as 别名]
def __call__(self, y, pred, sample_weight=None):
        """Compute the deviance (= 2 * negative log-likelihood).

        Parameters
        ----------
        y : array, shape (n_samples,)
            True labels

        pred : array, shape (n_samples,)
            Predicted labels

        sample_weight : array-like, shape (n_samples,), optional
            Sample weights.
        """
        # logaddexp(0, v) == log(1.0 + exp(v))
        pred = pred.ravel()
        if sample_weight is None:
            return -2.0 * np.mean((y * pred) - np.logaddexp(0.0, pred))
        else:
            return (-2.0 / sample_weight.sum() *
                    np.sum(sample_weight * ((y * pred) - np.logaddexp(0.0, pred)))) 

# 需要导入模块: import numpy [as 别名]
# 或者: from numpy import logaddexp [as 别名]
def get_collision_force(self, entity_a, entity_b):
        if (not entity_a.collide) or (not entity_b.collide):
            return [None, None] # not a collider
        if (entity_a is entity_b):
            return [None, None] # don't collide against itself
        # compute actual distance between entities
        delta_pos = entity_a.state.p_pos - entity_b.state.p_pos
        dist = np.sqrt(np.sum(np.square(delta_pos)))
        # minimum allowable distance
        dist_min = entity_a.size + entity_b.size
        # softmax penetration
        k = self.contact_margin
        penetration = np.logaddexp(0, -(dist - dist_min)/k)*k
        force = self.contact_force * delta_pos / dist * penetration
        force_a = +force if entity_a.movable else None
        force_b = -force if entity_b.movable else None
        return [force_a, force_b] 

# 需要导入模块: import numpy [as 别名]
# 或者: from numpy import logaddexp [as 别名]
def expected_forward_without_reduce(self, x_data, t_data, class_weight):
        x = numpy.rollaxis(x_data, 1, x_data.ndim).reshape(
            (t_data.size, x_data.shape[1]))
        t = t_data.ravel()

        loss_shape = x_data.shape[0:1] + x_data.shape[2:]
        loss_expect = numpy.zeros(loss_shape, x_data.dtype)
        for i, (ti, loss_idx) in enumerate(zip(t, numpy.ndindex(*loss_shape))):
            xi = x[i]
            if ti == -1:
                continue
            log_z = numpy.ufunc.reduce(numpy.logaddexp, xi)
            if class_weight is None:
                loss_expect[loss_idx] = -(xi - log_z)[ti]
            else:
                loss_expect[loss_idx] = -(xi - log_z)[ti] * class_weight[ti]
        return numpy.asarray(loss_expect, dtype=x.dtype) 

# 需要导入模块: import numpy [as 别名]
# 或者: from numpy import logaddexp [as 别名]
def sample_from_logprobabilities(log_probabilities, size=1, rst=None):
    """ Sample from log probabilities (robust to many bins and small probabilities).

        +-np.inf and np.nan will be interpreted as zero probability
    """
    if rst is None:
        rst = np.random
    log_probabilities = np.asarray(log_probabilities)

    valid_indices = np.nonzero(np.isfinite(log_probabilities))[0]
    valid_log_probabilities = log_probabilities[valid_indices]

    ndxs = valid_log_probabilities.argsort()
    sorted_log_probabilities = valid_log_probabilities[ndxs]
    cumsums = np.logaddexp.accumulate(sorted_log_probabilities)
    cumsums -= cumsums[-1]

    tmps = -rst.exponential(size=size)
    js = np.searchsorted(cumsums, tmps)
    valid_values = ndxs[js]
    values = valid_indices[valid_values]

    return values 

# 需要导入模块: import numpy [as 别名]
# 或者: from numpy import logaddexp [as 别名]
def sigmoid(self, a): #numerically stable sigmoid function
        return math.exp(-np.logaddexp(0, -a)) -0.5 #compresses values from 0 to 1 and is reduced by 0.5 to get between -1/2 and 1/2 

# 需要导入模块: import numpy [as 别名]
# 或者: from numpy import logaddexp [as 别名]
def ctc_loss(label, prob, remainder, seq_length, batch_size, num_gpu=1, big_num=1e10):
    label_ = [0, 0]
    prob[prob < 1 / big_num] = 1 / big_num
    log_prob = np.log(prob)

    l = len(label)
    for i in range(l):
        label_.append(int(label[i]))
        label_.append(0)

    l_ = 2 * l + 1
    a = np.full((seq_length, l_ + 1), -big_num)
    a[0][1] = log_prob[remainder][0]
    a[0][2] = log_prob[remainder][label_[2]]
    for i in range(1, seq_length):
        row = i * int(batch_size / num_gpu) + remainder
        a[i][1] = a[i - 1][1] + log_prob[row][0]
        a[i][2] = np.logaddexp(a[i - 1][2], a[i - 1][1]) + log_prob[row][label_[2]]
        for j in range(3, l_ + 1):
            a[i][j] = np.logaddexp(a[i - 1][j], a[i - 1][j - 1])
            if label_[j] != 0 and label_[j] != label_[j - 2]:
                a[i][j] = np.logaddexp(a[i][j], a[i - 1][j - 2])
            a[i][j] += log_prob[row][label_[j]]

    return -np.logaddexp(a[seq_length - 1][l_], a[seq_length - 1][l_ - 1])


# label is done with remove_blank
# pred is got from pred_best 

# 需要导入模块: import numpy [as 别名]
# 或者: from numpy import logaddexp [as 别名]
def full_compute(self, g, r_prev):
        '''Given prefix g, return the probability of all possible sequence y (where y = concat(g,c))
           This function computes all possible tokens for c (memory inefficient)'''
        prefix_length = len(g)
        last_char = g[-1] if prefix_length > 0 else 0

        # init. r
        r = np.full((self.input_length, 2, self.odim),
                    self.logzero, dtype=np.float32)

        # start from len(g) because is impossible for CTC to generate |y|>|X|
        start = max(1, prefix_length)

        if prefix_length == 0:
            r[0, 0, :] = self.x[0, :]    # if g = <sos>

        psi = r[start-1, 0, :]

        phi = np.logaddexp(r_prev[:, 0], r_prev[:, 1])

        for t in range(start, self.input_length):
            # prev_blank
            prev_blank = np.full((self.odim), r_prev[t-1, 1], dtype=np.float32)
            # prev_nonblank
            prev_nonblank = np.full(
                (self.odim), r_prev[t-1, 0], dtype=np.float32)
            prev_nonblank[last_char] = self.logzero

            phi = np.logaddexp(prev_nonblank, prev_blank)
            # P(h|current step is non-blank) = [ P(prev. step = y) + P()]*P(c)
            r[t, 0, :] = np.logaddexp(r[t-1, 0, :], phi) + self.x[t, :]
            # P(h|current step is blank) = [P(prev. step is blank) + P(prev. step is non-blank)]*P(now=blank)
            r[t, 1, :] = np.logaddexp(
                r[t-1, 1, :], r[t-1, 0, :]) + self.x[t, self.blank]
            psi = np.logaddexp(psi, phi+self.x[t, :])

        #psi[self.eos] = np.logaddexp(r_prev[-1,0], r_prev[-1,1])
        return psi, np.rollaxis(r, 2) 

# 需要导入模块: import numpy [as 别名]
# 或者: from numpy import logaddexp [as 别名]
def cheap_compute(self, g, r_prev, candidates):
        '''Given prefix g, return the probability of all possible sequence y (where y = concat(g,c))
           This function considers only those tokens in candidates for c (memory efficient)'''
        prefix_length = len(g)
        odim = len(candidates)
        last_char = g[-1] if prefix_length > 0 else 0

        # init. r
        r = np.full((self.input_length, 2, len(candidates)),
                    self.logzero, dtype=np.float32)

        # start from len(g) because is impossible for CTC to generate |y|>|X|
        start = max(1, prefix_length)

        if prefix_length == 0:
            r[0, 0, :] = self.x[0, candidates]    # if g = <sos>

        psi = r[start-1, 0, :]
        # Phi = (prev_nonblank,prev_blank)
        sum_prev = np.logaddexp(r_prev[:, 0], r_prev[:, 1])
        phi = np.repeat(sum_prev[..., None],odim,axis=-1)
        # Handle edge case : last tok of prefix in candidates
        if  prefix_length>0 and last_char in candidates:
            phi[:,candidates.index(last_char)] = r_prev[:,1]

        for t in range(start, self.input_length):
            # prev_blank
            # prev_blank = np.full((odim), r_prev[t-1, 1], dtype=np.float32)
            # prev_nonblank
            # prev_nonblank = np.full((odim), r_prev[t-1, 0], dtype=np.float32)
            # phi = np.logaddexp(prev_nonblank, prev_blank)
            # P(h|current step is non-blank) =  P(prev. step = y)*P(c)
            r[t, 0, :] = np.logaddexp( r[t-1, 0, :], phi[t-1]) + self.x[t, candidates]
            # P(h|current step is blank) = [P(prev. step is blank) + P(prev. step is non-blank)]*P(now=blank)
            r[t, 1, :] = np.logaddexp( r[t-1, 1, :], r[t-1, 0, :]) + self.x[t, self.blank]
            psi = np.logaddexp(psi, phi[t-1,]+self.x[t, candidates])

        # P(end of sentence) = P(g)
        if self.eos in candidates:
            psi[candidates.index(self.eos)] = sum_prev[-1]
        return psi, np.rollaxis(r, 2) 

# 需要导入模块: import numpy [as 别名]
# 或者: from numpy import logaddexp [as 别名]
def test_logaddexp_values(self):
        x = [1, 2, 3, 4, 5]
        y = [5, 4, 3, 2, 1]
        z = [6, 6, 6, 6, 6]
        for dt, dec_ in zip(['f', 'd', 'g'], [6, 15, 15]):
            xf = np.log(np.array(x, dtype=dt))
            yf = np.log(np.array(y, dtype=dt))
            zf = np.log(np.array(z, dtype=dt))
            assert_almost_equal(np.logaddexp(xf, yf), zf, decimal=dec_) 

# 需要导入模块: import numpy [as 别名]
# 或者: from numpy import logaddexp [as 别名]
def test_logaddexp_range(self):
        x = [1000000, -1000000, 1000200, -1000200]
        y = [1000200, -1000200, 1000000, -1000000]
        z = [1000200, -1000000, 1000200, -1000000]
        for dt in ['f', 'd', 'g']:
            logxf = np.array(x, dtype=dt)
            logyf = np.array(y, dtype=dt)
            logzf = np.array(z, dtype=dt)
            assert_almost_equal(np.logaddexp(logxf, logyf), logzf) 

# 需要导入模块: import numpy [as 别名]
# 或者: from numpy import logaddexp [as 别名]
def test_inf(self):
        inf = np.inf
        x = [inf, -inf,  inf, -inf, inf, 1,  -inf,  1]
        y = [inf,  inf, -inf, -inf, 1,   inf, 1,   -inf]
        z = [inf,  inf,  inf, -inf, inf, inf, 1,    1]
        with np.errstate(invalid='raise'):
            for dt in ['f', 'd', 'g']:
                logxf = np.array(x, dtype=dt)
                logyf = np.array(y, dtype=dt)
                logzf = np.array(z, dtype=dt)
                assert_equal(np.logaddexp(logxf, logyf), logzf)