Python tensorflow.clip_by_value函数代码示例

def discretize_range(discretize_fn, levels, low, high, thermometer=False):
  """Get range of discretized values for in the interval (low, high).

    For example, assume discretize_fn uniformly discretizes the values
    between 0 and 1 into 10 bins each represented by either a one hot encoding
    or a thermometer encoding. Then discretize_range(discretize_fn, .3, .7)
    would return [0., 0., 0., 1., 1., 1., 1., 0., 0., 0.]. Note that it's output
    is independent of the encoding used.

  Args:
    discretize_fn: Discretization function used to discretize input.
    levels: Number of levels to discretize the input into.
    low: Minimum value in the interval.
    high: Maximum value in the interval.
    thermometer: If True, then the discretize_fn returns thermometer codes,
        else it returns one hot codes. (Default: False).

  Returns:
    Mask of 1's over the interval.
  """
  low = tf.clip_by_value(low, 0., 1.)
  high = tf.clip_by_value(high, 0., 1.)
  out = 0.
  for alpha in np.linspace(0., 1., levels):
    q = discretize_fn(alpha * low + (1. - alpha) * high, levels, thermometer)

    # Convert into one hot encoding if q is in thermometer encoding
    if thermometer:
      q = discretization_utils.thermometer_to_one_hot(q, levels, flattened=True)
    out += q
  return tf.to_float(tf.greater(out, 0.))

def bayes_crossentropy(y_true, y_pred, nb_classes=None, reduction=tf.reduce_mean,
                       name=None):
  with tf.name_scope(name, "bayes_crossentropy", [y_true, y_pred]):
    y_pred_shape = y_pred.shape
    if y_pred_shape.ndims == 1 or y_pred_shape[-1].value == 1:
      if y_pred_shape.ndims == 1:
        y_pred = tf.expand_dims(y_pred, -1)
      y_pred0 = 1. - y_pred
      y_pred = tf.concat([y_pred0, y_pred], axis=-1)
    # get number of classes
    if y_true.shape.ndims == 1:
      if nb_classes is None:
        raise Exception('y_pred and y_true must be one_hot encoded, '
                        'otherwise you have to provide nb_classes.')
      y_true = tf.one_hot(y_true, depth=nb_classes)
    elif nb_classes is None:
      nb_classes = y_true.shape[1].value
    # avoid numerical instability with _EPSILON clipping
    y_pred = tf.clip_by_value(y_pred, EPS, 1.0 - EPS)
    # ====== check distribution ====== #
    distribution = tf.reduce_sum(y_true, axis=0)
    # probability distribution of each class
    prob_distribution = dimshuffle(distribution / tf.reduce_sum(distribution),
                                   ('x', 0))
    # we need to clip the prior probability distribution also
    prob_distribution = tf.clip_by_value(prob_distribution, EPS, 1.0 - EPS)
    # ====== init confusion info loss ====== #
    # weighted by y_true
    loss = y_true * tf.log(y_pred)
    loss = - 1 / nb_classes * tf.reduce_sum(loss / prob_distribution, axis=1)
    return reduction(loss)

    def _create_loss_and_optimizer(self, inputs, x_reconstr_mean, z_log_sigma_sq, z_mean):
        # The loss is composed of two terms:
        # 1.) The reconstruction loss (the negative log probability
        #     of the input under the reconstructed Bernoulli distribution
        #     induced by the decoder in the data space).
        #     This can be interpreted as the number of "nats" required
        #     for reconstructing the input when the activation in latent
        #     is given.
        # Adding 1e-10 to avoid evaluation of log(0.0)
        self.reconstr_loss = \
            -tf.reduce_sum(inputs * tf.log(tf.clip_by_value(x_reconstr_mean, 1e-9, 1.0))
                           + (1 - inputs) * tf.log(tf.clip_by_value(1 - x_reconstr_mean, 1e-9, 1.0)),
                           1)
        # 2.) The latent loss, which is defined as the Kullback Leibler divergence
        ##    between the distribution in latent space induced by the encoder on
        #     the data and some prior. This acts as a kind of regularize.
        #     This can be interpreted as the number of "nats" required
        #     for transmitting the the latent space distribution given
        #     the prior.
        self.latent_loss = -0.5 * tf.reduce_sum(1 + z_log_sigma_sq
                                                - tf.square(z_mean)
                                                - tf.exp(z_log_sigma_sq), 1)
        loss = tf.reduce_mean(self.reconstr_loss + self.latent_loss)   # average over batch

        optimizer = tf.train.AdamOptimizer(learning_rate=self.learning_rate).minimize(loss)
        return loss, optimizer

def tf_bivariate_normal(y, mu, sigma, rho, n_mixtures, batch_size):
    mu = tf.verify_tensor_all_finite(mu, "Mu not finite!")
    y = tf.verify_tensor_all_finite(y, "Y not finite!")
    delta = tf.sub(tf.tile(tf.expand_dims(y, 1), [1, n_mixtures, 1]), mu)
    delta = tf.verify_tensor_all_finite(delta, "Delta not finite!")
    sigma = tf.verify_tensor_all_finite(sigma, "Sigma not finite!")
    s = tf.reduce_prod(sigma, 2)
    s = tf.verify_tensor_all_finite(s, "S not finite!")
    # -1 <= rho <= 1
    z = tf.reduce_sum(tf.square(tf.div(delta, sigma + epsilon) + epsilon), 2) - \
        2 * tf.div(tf.mul(rho, tf.reduce_prod(delta, 2)), s + epsilon)
    
    z = tf.verify_tensor_all_finite(z, "Z not finite!")
    # 0 < negRho <= 1
    rho = tf.verify_tensor_all_finite(rho, "rho in bivariate normal not finite!")
    negRho = tf.clip_by_value(1 - tf.square(rho), epsilon, 1.0)
    negRho = tf.verify_tensor_all_finite(negRho, "negRho not finite!")
    # Note that if negRho goes near zero, or z goes really large, this explodes.
    negRho = tf.verify_tensor_all_finite(negRho, "negRho in bivariate normal not finite!")
    
    result = tf.clip_by_value(tf.exp(tf.div(-z, 2 * negRho)), 1.0e-8, 1.0e8)
    result = tf.verify_tensor_all_finite(result, "Result in bivariate normal not finite!")
    denom = 2 * np.pi * tf.mul(s, tf.sqrt(negRho))
    denom = tf.verify_tensor_all_finite(denom, "Denom in bivariate normal not finite!")
    result = tf.clip_by_value(tf.div(result, denom + epsilon), epsilon, 1.0)
    result = tf.verify_tensor_all_finite(result, "Result2 in bivariate normal not finite!")
    return result, delta

def translate(U, theta, out_height, out_width):
    num_batch = tf.shape(U)[0]
    height, width, num_ch = U.get_shape()[1:]
    height = height.value
    width = width.value
    num_ch = num_ch.value
    hwc = height*width*num_ch

    nind = tf.range(num_batch)
    x = repeat(tf.range(height), width)
    y = tf.tile(tf.range(width), tf.pack([height]))
    cind = tf.range(num_ch)

    nind = tf.expand_dims(repeat(nind, hwc), 1)
    x = tf.tile(tf.expand_dims(repeat(x, num_ch), 1), tf.pack([num_batch,1]))
    y = tf.tile(tf.expand_dims(repeat(y, num_ch), 1), tf.pack([num_batch,1]))
    cind = tf.tile(tf.expand_dims(cind, 1), tf.pack([num_batch*height*width,1]))

    dx, dy = tf.split(1, 2, theta)
    dx = tf.cast(tf.clip_by_value(dx, 0, out_height-height), 'int32')
    dx = tf.reshape(tf.tile(dx, tf.pack([1,hwc])), [-1,1])
    dy = tf.cast(tf.clip_by_value(dy, 0, out_width-width), 'int32')
    dy = tf.reshape(tf.tile(dy, tf.pack([1,hwc])), [-1,1])
    x = x + dx
    y = y + dy

    tind = tf.concat(1, [nind, x, y, cind])
    val = tf.reshape(U, [-1])
    T = tf.sparse_to_dense(tind,
            tf.pack([num_batch, out_height, out_width, num_ch]),
            val)
    T.set_shape([None, out_height, out_width, num_ch])
    return T

	def build_decoder(self, input_var):
		# Build the decoder
		if len(self.p_layers) > 0:
			self._decoder = Sequential('vae_decoder')
			self._decoder += FullyConnected(self.latent_dims, self.p_layers[0], coder_act_fn, name='fc_1')
			for i in xrange(1, len(self.p_layers)):
				self._decoder += FullyConnected(self.p_layers[i-1], self.p_layers[i], coder_act_fn, name='fc_%d'%(i+1))

			self.decoder = self._decoder(input_var)

			self._dec_mean = FullyConnected(self.p_layers[-1], self.input_dims, dec_mean_act_fn, name='dec_mean')
			self.dec_mean = self._dec_mean(self.decoder)
			self._dec_log_std_sq = FullyConnected(self.p_layers[-1], self.input_dims, mean_std_act_fn, name='dec_std')
			self.dec_log_std_sq = tf.clip_by_value(
				self._dec_log_std_sq(self.decoder),
				-self.sigma_clip,
				self.sigma_clip
			)

		else:
			self.decoder = input_var

			self._dec_mean = FullyConnected(self.latent_dims, self.input_dims, dec_mean_act_fn, name='dec_mean')
			self.dec_mean = self._dec_mean(self.decoder)
			self._dec_log_std_sq = FullyConnected(self.latent_dims, self.input_dims, mean_std_act_fn, name='dec_std')
			self.dec_log_std_sq = tf.clip_by_value(
				self._dec_log_std_sq(self.decoder),
				-self.sigma_clip,
				self.sigma_clip
			)

    def cross_entropy(u, label_u, alpha=0.5, normed=False):

        label_ip = tf.cast(
            tf.matmul(label_u, tf.transpose(label_u)), tf.float32)
        s = tf.clip_by_value(label_ip, 0.0, 1.0)

        # compute balance param
        # s_t \in {-1, 1}
        s_t = tf.multiply(tf.add(s, tf.constant(-0.5)), tf.constant(2.0))
        sum_1 = tf.reduce_sum(s)
        sum_all = tf.reduce_sum(tf.abs(s_t))
        balance_param = tf.add(tf.abs(tf.add(s, tf.constant(-1.0))),
                               tf.multiply(tf.div(sum_all, sum_1), s))

        if normed:
            # ip = tf.clip_by_value(tf.matmul(u, tf.transpose(u)), -1.5e1, 1.5e1)
            ip_1 = tf.matmul(u, tf.transpose(u))

            def reduce_shaper(t):
                return tf.reshape(tf.reduce_sum(t, 1), [tf.shape(t)[0], 1])
            mod_1 = tf.sqrt(tf.matmul(reduce_shaper(tf.square(u)),
                                      reduce_shaper(tf.square(u)), transpose_b=True))
            ip = tf.div(ip_1, mod_1)
        else:
            ip = tf.clip_by_value(tf.matmul(u, tf.transpose(u)), -1.5e1, 1.5e1)
        ones = tf.ones([tf.shape(u)[0], tf.shape(u)[0]])
        return tf.reduce_mean(tf.multiply(tf.log(ones + tf.exp(alpha * ip)) - s * alpha * ip, balance_param))

    def prob_is_largest(self, Y, mu, var, gh_x, gh_w):
        # work out what the mean and variance is of the indicated latent function.
        oh_on = tf.cast(tf.one_hot(tf.reshape(Y, (-1,)), self.num_classes, 1.0, 0.0), float_type)
        mu_selected = tf.reduce_sum(oh_on * mu, 1)
        var_selected = tf.reduce_sum(oh_on * var, 1)

        # generate Gauss Hermite grid
        X = tf.reshape(mu_selected, (-1, 1)) + gh_x * tf.reshape(
            tf.sqrt(tf.clip_by_value(2.0 * var_selected, 1e-10, np.inf)), (-1, 1)
        )

        # compute the CDF of the Gaussian between the latent functions and the grid (including the selected function)
        dist = (tf.expand_dims(X, 1) - tf.expand_dims(mu, 2)) / tf.expand_dims(
            tf.sqrt(tf.clip_by_value(var, 1e-10, np.inf)), 2
        )
        cdfs = 0.5 * (1.0 + tf.erf(dist / np.sqrt(2.0)))

        cdfs = cdfs * (1 - 2e-4) + 1e-4

        # blank out all the distances on the selected latent function
        oh_off = tf.cast(tf.one_hot(tf.reshape(Y, (-1,)), self.num_classes, 0.0, 1.0), float_type)
        cdfs = cdfs * tf.expand_dims(oh_off, 2) + tf.expand_dims(oh_on, 2)

        # take the product over the latent functions, and the sum over the GH grid.
        return tf.matmul(tf.reduce_prod(cdfs, reduction_indices=[1]), tf.reshape(gh_w / np.sqrt(np.pi), (-1, 1)))

    def _create_cost_function_node(self, model_output, ref_input, regterm=None):

        """ Create the cost function node.
        :param model_output: model output node
        :param ref_input: reference input placeholder node
        :param regterm: regularization term
        :return: self
        """

        with tf.name_scope("cost"):
            if self.loss_func == 'cross_entropy':
                cost = - tf.reduce_mean(ref_input * tf.log(tf.clip_by_value(model_output, 1e-10, float('inf'))) +
                                        (1 - ref_input) * tf.log(tf.clip_by_value(1 - model_output, 1e-10, float('inf'))))

            elif self.loss_func == 'softmax_cross_entropy':
                softmax = tf.nn.softmax(model_output)
                cost = - tf.reduce_mean(ref_input * tf.log(softmax) + (1 - ref_input) * tf.log(1 - softmax))

            elif self.loss_func == 'mean_squared':
                cost = tf.sqrt(tf.reduce_mean(tf.square(ref_input - model_output)))

            else:
                cost = None

        if cost is not None:
            self.cost = cost + regterm if regterm is not None else cost
            _ = tf.scalar_summary(self.loss_func, self.cost)
        else:
            self.cost = None

def focal_loss(prediction_tensor, target_tensor, weights=None, alpha=0.25, gamma=2):
    r"""Compute focal loss for predictions.

        Multi-labels Focal loss formula:
            FL = -alpha * (z-p)^gamma * log(p) -(1-alpha) * p^gamma * log(1-p)
                 ,which alpha = 0.25, gamma = 2, p = sigmoid(x), z = target_tensor.

    Args:
     prediction_tensor: A float tensor of shape [batch_size, num_anchors,
        num_classes] representing the predicted logits for each class
     target_tensor: A float tensor of shape [batch_size, num_anchors,
        num_classes] representing one-hot encoded classification targets
     weights: A float tensor of shape [batch_size, num_anchors]
     alpha: A scalar tensor for focal loss alpha hyper-parameter
     gamma: A scalar tensor for focal loss gamma hyper-parameter
    Returns:
        loss: A (scalar) tensor representing the value of the loss function
    """
    sigmoid_p = tf.nn.sigmoid(prediction_tensor)
    zeros = array_ops.zeros_like(sigmoid_p, dtype=sigmoid_p.dtype)
    pos_p_sub = array_ops.where(target_tensor >= sigmoid_p, target_tensor - sigmoid_p, zeros)
    neg_p_sub = array_ops.where(target_tensor > zeros, zeros, sigmoid_p)
    per_entry_cross_ent = - alpha * (pos_p_sub ** gamma) * tf.log(tf.clip_by_value(sigmoid_p, 1e-8, 1.0)) \
                          - (1 - alpha) * (neg_p_sub ** gamma) * tf.log(tf.clip_by_value(1.0 - sigmoid_p, 1e-8, 1.0))
    return tf.reduce_mean(per_entry_cross_ent)

def batchnorm(x, gamma, beta, r_mean, r_var):
  mean, var = tf.nn.moments(x,[0])
  update_mean = tf.assign(r_mean,0.9 * r_mean + 0.1 * mean)
  update_var = tf.assign(r_var,0.9 * r_var + 0.1 * var)
  with tf.control_dependencies([update_mean,update_var]):
    return tf.nn.batch_normalization(x,tf.clip_by_value(r_mean,1e-10,100),tf.clip_by_value(r_var,1e-10,100),
                                     offset=beta,scale=gamma,variance_epsilon=1e-5)

def clip_weights_with_threshold(max_threshold):
    global weights
    for op,w in weights.items():
        if 'conv' in op:
            weights[op] = tf.clip_by_value(weights[op], -max_threshold, max_threshold, name=None)
        elif 'fulcon' in op:
            weights[op] = tf.clip_by_value(weights[op], -max_threshold, max_threshold, name=None)

    def _loss_x_entropy(self, x, z, noise=None):
        with tf.name_scope("xentropy_loss"):
            z_clipped = tf.clip_by_value(z, FLAGS.zero_bound, FLAGS.one_bound)
            z_minus_1_clipped = tf.clip_by_value((1.0 - z), FLAGS.zero_bound, FLAGS.one_bound)
            x_clipped = tf.clip_by_value(x, FLAGS.zero_bound, FLAGS.one_bound)
            x_minus_1_clipped = tf.clip_by_value((1.0 - x), FLAGS.zero_bound, FLAGS.one_bound)
            
            # cross_entropy = x * log(z) + (1 - x) * log(1 - z)
            
            cross_entropy = tf.add(tf.mul(tf.log(z_clipped), x_clipped),
                                   tf.mul(tf.log(z_minus_1_clipped), x_minus_1_clipped), name='X-Entr')

            if noise:
                with tf.name_scope("Given_Emphasis"):
                    a, b = self._get_emph_params
                    corrupted = tf.select(noise, cross_entropy, tf.zeros_like(cross_entropy), name='Corrupted_Emphasis')
                    
                    # OR -- tf.select(tf.logical_not(noisy_points), cross_entropy, tf.zeros_like(cross_entropy), name='Uncorrupted_Emphasis')
                    uncorrupted = tf.select(noise, tf.zeros_like(cross_entropy), cross_entropy, name='Uncorrupted_Emphasis')
                    
                    loss = a * (-1 * tf.reduce_sum(corrupted, 1)) + b * (-1 * tf.reduce_sum(uncorrupted, 1))
            else:
                # Sum the cost for each example
                loss = -1 * tf.reduce_sum(cross_entropy, 1)
        
            # Reduce mean to find the overall cost of the loss
            cross_entropy_mean = tf.reduce_mean(loss, name='xentropy_mean')
    
            return cross_entropy_mean

  def build_model(self, reuse, dev, ntype):
    with tf.variable_scope(self.name) and tf.device(dev):
      if reuse:
        tf.get_variable_scope().reuse_variables()
        assert tf.get_variable_scope().reuse

      # Set inputs of networks
      self.minimap = tf.placeholder(tf.float32, [None, U.minimap_channel(), self.msize, self.msize], name='minimap')
      self.screen = tf.placeholder(tf.float32, [None, U.screen_channel(), self.ssize, self.ssize], name='screen')
      self.info = tf.placeholder(tf.float32, [None, self.isize], name='info')

      # Build networks
      net = build_net(self.minimap, self.screen, self.info, self.msize, self.ssize, len(actions.FUNCTIONS), ntype)
      self.spatial_action, self.non_spatial_action, self.value = net

      # Set targets and masks
      self.valid_spatial_action = tf.placeholder(tf.float32, [None], name='valid_spatial_action')
      self.spatial_action_selected = tf.placeholder(tf.float32, [None, self.ssize**2], name='spatial_action_selected')
      self.valid_non_spatial_action = tf.placeholder(tf.float32, [None, len(actions.FUNCTIONS)], name='valid_non_spatial_action')
      self.non_spatial_action_selected = tf.placeholder(tf.float32, [None, len(actions.FUNCTIONS)], name='non_spatial_action_selected')
      self.value_target = tf.placeholder(tf.float32, [None], name='value_target')

      # Compute log probability
      spatial_action_prob = tf.reduce_sum(self.spatial_action * self.spatial_action_selected, axis=1)
      spatial_action_log_prob = tf.log(tf.clip_by_value(spatial_action_prob, 1e-10, 1.))
      non_spatial_action_prob = tf.reduce_sum(self.non_spatial_action * self.non_spatial_action_selected, axis=1)
      valid_non_spatial_action_prob = tf.reduce_sum(self.non_spatial_action * self.valid_non_spatial_action, axis=1)
      valid_non_spatial_action_prob = tf.clip_by_value(valid_non_spatial_action_prob, 1e-10, 1.)
      non_spatial_action_prob = non_spatial_action_prob / valid_non_spatial_action_prob
      non_spatial_action_log_prob = tf.log(tf.clip_by_value(non_spatial_action_prob, 1e-10, 1.))
      self.summary.append(tf.summary.histogram('spatial_action_prob', spatial_action_prob))
      self.summary.append(tf.summary.histogram('non_spatial_action_prob', non_spatial_action_prob))

      # Compute losses, more details in https://arxiv.org/abs/1602.01783
      # Policy loss and value loss
      action_log_prob = self.valid_spatial_action * spatial_action_log_prob + non_spatial_action_log_prob
      advantage = tf.stop_gradient(self.value_target - self.value)
      policy_loss = - tf.reduce_mean(action_log_prob * advantage)
      value_loss = - tf.reduce_mean(self.value * advantage)
      self.summary.append(tf.summary.scalar('policy_loss', policy_loss))
      self.summary.append(tf.summary.scalar('value_loss', value_loss))

      # TODO: policy penalty
      loss = policy_loss + value_loss

      # Build the optimizer
      self.learning_rate = tf.placeholder(tf.float32, None, name='learning_rate')
      opt = tf.train.RMSPropOptimizer(self.learning_rate, decay=0.99, epsilon=1e-10)
      grads = opt.compute_gradients(loss)
      cliped_grad = []
      for grad, var in grads:
        self.summary.append(tf.summary.histogram(var.op.name, var))
        self.summary.append(tf.summary.histogram(var.op.name+'/grad', grad))
        grad = tf.clip_by_norm(grad, 10.0)
        cliped_grad.append([grad, var])
      self.train_op = opt.apply_gradients(cliped_grad)
      self.summary_op = tf.summary.merge(self.summary)

      self.saver = tf.train.Saver(max_to_keep=100)

    def _forward(self, x, gpu):
        hps = self.hps

        x = tf.to_float(x)
        x = tf.clip_by_value((x + 0.5) / 256.0, 0.0, 1.0) - 0.5

        # Input images are repeated k times on the input.
        # This is used for Importance Sampling loss (k is number of samples).
        data_size = hps.batch_size * hps.k
        x = repeat(x, hps.k)

        orig_x = x
        h_size = hps.h_size

        with arg_scope([conv2d, deconv2d], init=(self.mode == "init")):
            layers = []
            for i in range(hps.depth):
                layers.append([])
                for j in range(hps.num_blocks):
                    downsample = (i > 0) and (j == 0)
                    layers[-1].append(IAFLayer(hps, self.mode, downsample))

            h = conv2d("x_enc", x, h_size, [5, 5], [2, 2])  # -> [16, 16]
            for i, layer in enumerate(layers):
                for j, sub_layer in enumerate(layer):
                    with tf.variable_scope("IAF_%d_%d" % (i, j)):
                        h = sub_layer.up(h)

            # top->down
            self.h_top = h_top = tf.get_variable("h_top", [h_size], initializer=tf.zeros_initializer)
            h_top = tf.reshape(h_top, [1, -1, 1, 1])
            h = tf.tile(h_top, [data_size, 1, hps.image_size / 2 ** len(layers), hps.image_size / 2 ** len(layers)])
            kl_cost = kl_obj = 0.0

            for i, layer in reversed(list(enumerate(layers))):
                for j, sub_layer in reversed(list(enumerate(layer))):
                    with tf.variable_scope("IAF_%d_%d" % (i, j)):
                        h, cur_obj, cur_cost = sub_layer.down(h)
                        kl_obj += cur_obj
                        kl_cost += cur_cost

                        if self.mode == "train" and gpu == hps.num_gpus - 1:
                            tf.scalar_summary("model/kl_obj_%02d_%02d" % (i, j), tf.reduce_mean(cur_obj))
                            tf.scalar_summary("model/kl_cost_%02d_%02d" % (i, j), tf.reduce_mean(cur_cost))

            x = tf.nn.elu(h)
            x = deconv2d("x_dec", x, 3, [5, 5])
            x = tf.clip_by_value(x, -0.5 + 1 / 512., 0.5 - 1 / 512.)

        log_pxz = discretized_logistic(x, self.dec_log_stdv, sample=orig_x)
        obj = tf.reduce_sum(kl_obj - log_pxz)

        if self.mode == "train" and gpu == hps.num_gpus - 1:
            tf.scalar_summary("model/log_pxz", -tf.reduce_mean(log_pxz))
            tf.scalar_summary("model/kl_obj", tf.reduce_mean(kl_obj))
            tf.scalar_summary("model/kl_cost", tf.reduce_mean(kl_cost))

        loss = tf.reduce_sum(compute_lowerbound(log_pxz, kl_cost, hps.k))
        return x, obj, loss