Python tensorflow.while_loop方法代碼示例

# 需要導入模塊: import tensorflow [as 別名]
# 或者: from tensorflow import while_loop [as 別名]
def _inv_preemphasis(x):
    N = tf.shape(x)[0]
    i = tf.constant(0)
    W = tf.zeros(shape=tf.shape(x), dtype=tf.float32)

    def condition(i, y):
        return tf.less(i, N)

    def body(i, y):
        tmp = tf.slice(x, [0], [i + 1])
        tmp = tf.concat([tf.zeros([N - i - 1]), tmp], -1)
        y = hparams.preemphasis * y + tmp
        i = tf.add(i, 1)
        return [i, y]

    final = tf.while_loop(condition, body, [i, W])

    y = final[1]

    return y 

# 需要導入模塊: import tensorflow [as 別名]
# 或者: from tensorflow import while_loop [as 別名]
def _leapfrog(self, q, p, step_size, get_gradient, mass):
        def loop_cond(i, q, p):
            return i < self.n_leapfrogs + 1

        def loop_body(i, q, p):
            step_size1 = tf.cond(i > 0,
                                 lambda: step_size,
                                 lambda: tf.constant(0.0, dtype=tf.float32))

            step_size2 = tf.cond(tf.logical_and(tf.less(i, self.n_leapfrogs),
                                                tf.less(0, i)),
                                 lambda: step_size,
                                 lambda: step_size / 2)

            q, p = leapfrog_integrator(q, p, step_size1, step_size2,
                                       lambda q: get_gradient(q), mass)
            return [i + 1, q, p]

        i = tf.constant(0)
        _, q, p = tf.while_loop(loop_cond,
                                loop_body,
                                [i, q, p],
                                back_prop=False,
                                parallel_iterations=1)
        return q, p 

# 需要導入模塊: import tensorflow [as 別名]
# 或者: from tensorflow import while_loop [as 別名]
def ngctc_loss(term_probs, targets,seq_len,tar_len):
    bs = tf.to_int32(tf.shape(term_probs)[0])
    #loss = 0.
    cond = lambda j,loss: tf.less(j, bs)
    j = tf.constant(0,dtype=tf.int32)
    loss = tf.constant(0,dtype=tf.float64)
    def body(j,loss):
        idx = tf.expand_dims(targets[j,:tar_len[j]],1)
        st = tf.transpose(term_probs[j], (1, 0))
        st = tf.transpose(tf.gather_nd(st, idx), (1, 0))
        length = seq_len[j]
        loss += -tf.reduce_sum(tf.log(forward_ngctc(st, length))/tf.to_double(bs)) # negative log likelihood for whole batch
        return tf.add(j,1),loss # average loss over batches

    out = tf.while_loop(cond,body,loop_vars= [j,loss])

    return out[1] 

# 需要導入模塊: import tensorflow [as 別名]
# 或者: from tensorflow import while_loop [as 別名]
def ngctc_decode(term_probs, targets,seq_len,tar_len):
    max_seq_len  = tf.to_int32(tf.reduce_max(seq_len))
    bs = tf.to_int32(tf.shape(term_probs)[0])
    #loss = 0.
    cond = lambda j,loss: tf.less(j, bs)
    j = tf.constant(0,dtype=tf.int32)
    decoded = tf.zeros([1,max_seq_len],dtype=tf.int32)
    def body(j,decoded):
        idx = tf.expand_dims(targets[j,:tar_len[j]],1)
        st = tf.transpose(term_probs[j], (1, 0))
        st = tf.transpose(tf.gather_nd(st, idx), (1, 0))
        length = tf.to_int32(seq_len[j])
        alphas = forward_ngctc(st, length,inference=True) # get essentially the probability of being at each node
        dec = tf.to_int32(tf.argmax(alphas,axis=1)) # decode that by taking the argmax for each column of alphas
        dec = tf.concat([dec,tf.zeros([max_seq_len-length],dtype=tf.int32)],axis=0)

        decoded = tf.concat([decoded,[dec]],axis=0)

        return tf.add(j,1),decoded

    out = tf.while_loop(cond,body,loop_vars= [j,decoded],shape_invariants=[tf.TensorShape(None),tf.TensorShape([None, None])])
    return out[1] 

# 需要導入模塊: import tensorflow [as 別名]
# 或者: from tensorflow import while_loop [as 別名]
def broadcast_against(tensor, against_expr):
    """Adds trailing dimensions to mask to enable broadcasting against data

    :param tensor: tensor to be broadcasted
    :param against_expr: tensor will be broadcasted against it
    :return: mask expr with tf.rank(mask) == tf.rank(data)
    """

    def cond(data, tensor):
        return tf.less(tf.rank(tensor), tf.rank(data))

    def body(data, tensor):
        return data, tf.expand_dims(tensor, -1)

    shape_invariants = [against_expr.get_shape(), tf.TensorShape(None)]
    _, tensor = tf.while_loop(cond, body, [against_expr, tensor], shape_invariants)
    return tensor 

# 需要導入模塊: import tensorflow [as 別名]
# 或者: from tensorflow import while_loop [as 別名]
def search(self, initial_ids, initial_cache):
    """Beam search for sequences with highest scores."""
    state, state_shapes = self._create_initial_state(initial_ids, initial_cache)

    finished_state = tf.while_loop(
        cond=self._continue_search, body=self._search_step, loop_vars=[state],
        shape_invariants=[state_shapes], parallel_iterations=1, back_prop=False)
    finished_state = finished_state[0]

    alive_seq = finished_state[_StateKeys.ALIVE_SEQ]
    alive_log_probs = finished_state[_StateKeys.ALIVE_LOG_PROBS]
    finished_seq = finished_state[_StateKeys.FINISHED_SEQ]
    finished_scores = finished_state[_StateKeys.FINISHED_SCORES]
    finished_flags = finished_state[_StateKeys.FINISHED_FLAGS]

    # Account for corner case where there are no finished sequences for a
    # particular batch item. In that case, return alive sequences for that batch
    # item.
    finished_seq = tf.compat.v1.where(
        tf.reduce_any(input_tensor=finished_flags, axis=1), finished_seq, alive_seq)
    finished_scores = tf.compat.v1.where(
        tf.reduce_any(input_tensor=finished_flags, axis=1), finished_scores, alive_log_probs)
    return finished_seq, finished_scores 

# 需要導入模塊: import tensorflow [as 別名]
# 或者: from tensorflow import while_loop [as 別名]
def double_factorial(n):
  """Computes the double factorial of `n`.

  Note:
    In the following, A1 to An are optional batch dimensions.

  Args:
    n: A tensor of shape `[A1, ..., An]` containing positive integer values.

  Returns:
    A tensor of shape `[A1, ..., An]` containing the double factorial of `n`.
  """
  n = tf.convert_to_tensor(value=n)

  two = tf.ones_like(n) * 2
  result = tf.ones_like(n)
  _, result, _ = tf.while_loop(
      cond=_double_factorial_loop_condition,
      body=_double_factorial_loop_body,
      loop_vars=[n, result, two])
  return result 

# 需要導入模塊: import tensorflow [as 別名]
# 或者: from tensorflow import while_loop [as 別名]
def _reshape_decoder_outputs(self):
        """ Reshape decoder_outputs into shape [?, _NUM_UNITS]. """
        def concat_output_slices(idx, val):
            output_slice = tf.slice(
                    input_ = self.decoder_outputs,
                    begin = [idx, 0, 0],
                    size = [1, self.decoder_input_length[idx],  _NUM_UNITS])
            return tf.add(idx, 1),\
                    tf.concat([val, tf.squeeze(output_slice, axis = 0)], 
                            axis = 0)
        tf_i = tf.constant(0)
        tf_v = tf.zeros(shape = [0, _NUM_UNITS], dtype = tf.float32)
        _, reshaped_outputs = tf.while_loop(
                cond = lambda i, v: i < _BATCH_SIZE,
                body = concat_output_slices,
                loop_vars = [tf_i, tf_v],
                shape_invariants = [tf.TensorShape([]),
                    tf.TensorShape([None, _NUM_UNITS])])
        tf.TensorShape([None, _NUM_UNITS]).\
                assert_same_rank(reshaped_outputs.shape)
        return reshaped_outputs 

# 需要導入模塊: import tensorflow [as 別名]
# 或者: from tensorflow import while_loop [as 別名]
def test_import_tf_comp_with_while_loop(self):

    @computations.tf_computation(tf.float32)
    def comp(x):
      # An example of a loop with variables that computes 2^x by counting from
      # x down to 0, and doubling the result in each iteration.
      a = tf.Variable(0.0)
      b = tf.Variable(1.0)
      with tf.control_dependencies([a.initializer, b.initializer]):
        with tf.control_dependencies([a.assign(x)]):
          cond_fn = lambda a, b: a > 0
          body_fn = lambda a, b: (a - 1.0, b * 2.0)
          return tf.while_loop(cond_fn, body_fn, (a, b))[1]

    module, mlir = self._import_compile_and_return_module_and_mlir(comp)

    # Not checking the full MLIR in the long generated body, just that we can
    # successfully ingest TF code containing a while loop here, end-to-end. We
    # need some form of looping support in lieu of `tf.data.Dataset.reduce()`.
    self._assert_mlir_contains_pattern(
        mlir, ['func @fn(%arg0: tensor<f32>) -> tensor<f32>'])

    result = runtime.compile_and_run_on_args(module, backend_info.VULKAN_SPIRV,
                                             np.float32(5.0))
    self.assertEqual(result, 32.0) 

# 需要導入模塊: import tensorflow [as 別名]
# 或者: from tensorflow import while_loop [as 別名]
def build_pgd_attack(self, eps):
        victim_embeddings = tf.constant(self.victim_embeddings, dtype=tf.float32)

        def one_step_attack(image, grad):
            """
            core components of this attack are:
            (a) PGD adversarial attack (https://arxiv.org/pdf/1706.06083.pdf)
            (b) momentum (https://arxiv.org/pdf/1710.06081.pdf)
            (c) input diversity (https://arxiv.org/pdf/1803.06978.pdf)
            """
            orig_image = image
            image = self.structure(image)
            image = (image - 127.5) / 128.0
            image = image + tf.random_uniform(tf.shape(image), minval=-1e-2, maxval=1e-2)
            prelogits, _ = self.network.inference(image, 1.0, False, bottleneck_layer_size=512)
            embeddings = tf.nn.l2_normalize(prelogits, 1, 1e-10, name='embeddings')

            embeddings = tf.reshape(embeddings[0], [512, 1])
            objective = tf.reduce_mean(tf.matmul(victim_embeddings, embeddings))  # to be maximized

            noise, = tf.gradients(objective, orig_image)

            noise = noise / tf.reduce_mean(tf.abs(noise), [1, 2, 3], keep_dims=True)
            noise = 0.9 * grad + noise

            adv = tf.clip_by_value(orig_image + tf.sign(noise) * 1.0, lower_bound, upper_bound)
            return adv, noise

        input = tf.to_float(self.image_batch)
        lower_bound = tf.clip_by_value(input - eps, 0, 255.)
        upper_bound = tf.clip_by_value(input + eps, 0, 255.)

        with tf.variable_scope(tf.get_variable_scope(), reuse=tf.AUTO_REUSE):
            adv, _ = tf.while_loop(
                lambda _, __: True, one_step_attack,
                (input, tf.zeros_like(input)),
                back_prop=False,
                maximum_iterations=100,
                parallel_iterations=1)
        self.adv_image = adv
        return adv 

# 需要導入模塊: import tensorflow [as 別名]
# 或者: from tensorflow import while_loop [as 別名]
def attack(self, x, y):
        """
        This method creates a symbolic graph that given an input image,
        first randomly perturbs the image. The
        perturbation is bounded to an epsilon ball. Then multiple steps of
        gradient descent is performed to increase the probability of a target
        label or decrease the probability of the ground-truth label.

        :param x: A tensor with the input image.
        """
        import tensorflow as tf
        from cleverhans.utils_tf import clip_eta

        if self.rand_init:
            eta = tf.random_uniform(
                tf.shape(x), -self.eps, self.eps, dtype=self.tf_dtype)
            eta = clip_eta(eta, self.ord, self.eps)
        else:
            eta = tf.zeros_like(x)

        def cond(i, _):
            return tf.less(i, self.nb_iter)

        def body(i, e):
            new_eta = self.attack_single_step(x, e, y)
            return i + 1, new_eta

        _, eta = tf.while_loop(cond, body, [tf.zeros([]), eta], back_prop=True)

        adv_x = x + eta
        if self.clip_min is not None and self.clip_max is not None:
            adv_x = tf.clip_by_value(adv_x, self.clip_min, self.clip_max)

        return adv_x 

# 需要導入模塊: import tensorflow [as 別名]
# 或者: from tensorflow import while_loop [as 別名]
def _compute_gradients(self, loss_fn, x, unused_optim_state):
        """Compute gradient estimates using SPSA."""
        # Assumes `x` is a list, containing a [1, H, W, C] image
        assert len(x) == 1 and x[0].get_shape().as_list()[0] == 1
        x = x[0]
        x_shape = x.get_shape().as_list()

        def body(i, grad_array):
            delta = self._delta
            delta_x = self._get_delta(x, delta)
            delta_x = tf.concat([delta_x, -delta_x], axis=0)
            loss_vals = tf.reshape(
                loss_fn(x + delta_x),
                [2 * self._num_samples] + [1] * (len(x_shape) - 1))
            avg_grad = reduce_mean(loss_vals * delta_x, axis=0) / delta
            avg_grad = tf.expand_dims(avg_grad, axis=0)
            new_grad_array = grad_array.write(i, avg_grad)
            return i + 1, new_grad_array

        def cond(i, _):
            return i < self._num_iters

        _, all_grads = tf.while_loop(
            cond,
            body,
            loop_vars=[
                0, tf.TensorArray(size=self._num_iters, dtype=tf_dtype)
            ],
            back_prop=False,
            parallel_iterations=1)
        avg_grad = reduce_sum(all_grads.stack(), axis=0)
        return [avg_grad] 

# 需要導入模塊: import tensorflow [as 別名]
# 或者: from tensorflow import while_loop [as 別名]
def attack(self, x, y):
        """
        This method creates a symbolic graph that given an input image,
        first randomly perturbs the image. The
        perturbation is bounded to an epsilon ball. Then multiple steps of
        gradient descent is performed to increase the probability of a target
        label or decrease the probability of the ground-truth label.

        :param x: A tensor with the input image.
        """
        import tensorflow as tf
        from cleverhans.utils_tf import clip_eta

        if self.rand_init:
            eta = tf.random_uniform(
                tf.shape(x), -self.eps, self.eps, dtype=self.tf_dtype)
            eta = clip_eta(eta, self.ord, self.eps)
            temp_logits = self.model.get_logits(x)
            from cleverhans.loss import attack_softmax_cross_entropy

            temp_loss = attack_softmax_cross_entropy(y, temp_logits)
            adv_loss_fp = temp_loss
        else:
            eta = tf.zeros_like(x)

        def cond(i, _, alf):
            return tf.less(i, self.nb_iter)

        def body(i, e, alf):
            new_eta, adv_loss_fp = self.attack_single_step(x, e, y)
            return i + 1, new_eta, adv_loss_fp

        _, eta, adv_loss_fp = tf.while_loop(cond, body, [tf.zeros([]), eta, adv_loss_fp], back_prop=True)

        adv_x = x + eta
        if self.clip_min is not None and self.clip_max is not None:
            adv_x = tf.clip_by_value(adv_x, self.clip_min, self.clip_max)

        return adv_x, adv_loss_fp 

# 需要導入模塊: import tensorflow [as 別名]
# 或者: from tensorflow import while_loop [as 別名]
def testParsingReaderOpWhileLoop(self):
    feature_size = 3
    batch_size = 5

    def ParserEndpoints():
      return gen_parser_ops.gold_parse_reader(self._task_context,
                                              feature_size,
                                              batch_size,
                                              corpus_name='training-corpus')

    with self.test_session() as sess:
      # The 'condition' and 'body' functions expect as many arguments as there
      # are loop variables. 'condition' depends on the 'epoch' loop variable
      # only, so we disregard the remaining unused function arguments. 'body'
      # returns a list of updated loop variables.
      def Condition(epoch, *unused_args):
        return tf.less(epoch, 2)

      def Body(epoch, num_actions, *feature_args):
        # By adding one of the outputs of the reader op ('epoch') as a control
        # dependency to the reader op we force the repeated evaluation of the
        # reader op.
        with epoch.graph.control_dependencies([epoch]):
          features, epoch, gold_actions = ParserEndpoints()
        num_actions = tf.maximum(num_actions,
                                 tf.reduce_max(gold_actions, [0], False) + 1)
        feature_ids = []
        for i in range(len(feature_args)):
          feature_ids.append(features[i])
        return [epoch, num_actions] + feature_ids

      epoch = ParserEndpoints()[-2]
      num_actions = tf.constant(0)
      loop_vars = [epoch, num_actions]

      res = sess.run(
          tf.while_loop(Condition, Body, loop_vars,
                        shape_invariants=[tf.TensorShape(None)] * 2,
                        parallel_iterations=1))
      logging.info('Result: %s', res)
      self.assertEqual(res[0], 2) 

# 需要導入模塊: import tensorflow [as 別名]
# 或者: from tensorflow import while_loop [as 別名]
def _BuildSequence(self,
                     batch_size,
                     max_steps,
                     features,
                     state,
                     use_average=False):
    """Adds a sequence of beam parsing steps."""
    def Advance(state, step, scores_array, alive, alive_steps, *features):
      scores = self._BuildNetwork(features,
                                  return_average=use_average)['logits']
      scores_array = scores_array.write(step, scores)
      features, state, alive = (
          gen_parser_ops.beam_parser(state, scores, self._feature_size))
      return [state, step + 1, scores_array, alive, alive_steps + tf.cast(
          alive, tf.int32)] + list(features)

    # args: (state, step, scores_array, alive, alive_steps, *features)
    def KeepGoing(*args):
      return tf.logical_and(args[1] < max_steps, tf.reduce_any(args[3]))

    step = tf.constant(0, tf.int32, [])
    scores_array = tensor_array_ops.TensorArray(dtype=tf.float32,
                                                size=0,
                                                dynamic_size=True)
    alive = tf.constant(True, tf.bool, [batch_size])
    alive_steps = tf.constant(0, tf.int32, [batch_size])
    t = tf.while_loop(
        KeepGoing,
        Advance,
        [state, step, scores_array, alive, alive_steps] + list(features),
        shape_invariants=[tf.TensorShape(None)] * (len(features) + 5),
        parallel_iterations=100)

    # Link to the final nodes/values of ops that have passed through While:
    return {'state': t[0],
            'concat_scores': t[2].concat(),
            'alive': t[3],
            'alive_steps': t[4]}