Python math_ops.minimum方法代码示例

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import minimum [as 别名]
def _optimal_step_size(last_step,
                       error_ratio,
                       safety=0.9,
                       ifactor=10.0,
                       dfactor=0.2,
                       order=5,
                       name=None):
  """Calculate the optimal size for the next Runge-Kutta step."""
  with ops.name_scope(
      name, 'optimal_step_size', [last_step, error_ratio]) as scope:
    error_ratio = math_ops.cast(error_ratio, last_step.dtype)
    exponent = math_ops.cast(1 / order, last_step.dtype)
    # this looks more complex than necessary, but importantly it keeps
    # error_ratio in the numerator so we can't divide by zero:
    factor = math_ops.maximum(
        1 / ifactor,
        math_ops.minimum(error_ratio ** exponent / safety, 1 / dfactor))
    return math_ops.div(last_step, factor, name=scope) 

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import minimum [as 别名]
def _adaptive_max_norm(norm, std_factor, decay, global_step, epsilon, name):
  """Find max_norm given norm and previous average."""
  with vs.variable_scope(name, "AdaptiveMaxNorm", [norm]):
    log_norm = math_ops.log(norm + epsilon)

    def moving_average(name, value, decay):
      moving_average_variable = vs.get_variable(
          name, shape=value.get_shape(), dtype=value.dtype,
          initializer=init_ops.zeros_initializer, trainable=False)
      return moving_averages.assign_moving_average(
          moving_average_variable, value, decay, zero_debias=False)

    # quicker adaptation at the beginning
    if global_step is not None:
      n = math_ops.to_float(global_step)
      decay = math_ops.minimum(decay, n / (n + 1.))

    # update averages
    mean = moving_average("mean", log_norm, decay)
    sq_mean = moving_average("sq_mean", math_ops.square(log_norm), decay)

    variance = sq_mean - math_ops.square(mean)
    std = math_ops.sqrt(math_ops.maximum(epsilon, variance))
    max_norms = math_ops.exp(mean + std_factor*std)
    return max_norms, mean 

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import minimum [as 别名]
def _huber_loss(labels, predictions, config):
        """ Huber loss tensor"""
        delta = config.huber_delta
        predictions = math_ops.to_float(predictions)
        labels = math_ops.to_float(labels)
        predictions.get_shape().assert_is_compatible_with(labels.get_shape())
        error = math_ops.subtract(predictions, labels)
        abs_error = math_ops.abs(error)
        quadratic = math_ops.minimum(abs_error, delta)
        # The following expression is the same in value as
        # tf.maximum(abs_error - delta, 0), but importantly the gradient for the
        # expression when abs_error == delta is 0 (for tf.maximum it would be 1).
        # This is necessary to avoid doubling the gradient, since there is already a
        # nonzero contribution to the gradient from the quadratic term.
        linear = math_ops.subtract(abs_error, quadratic)
        losses = math_ops.add(
            math_ops.multiply(
                ops.convert_to_tensor(0.5, dtype=quadratic.dtype),
                math_ops.multiply(quadratic, quadratic)),
            math_ops.multiply(delta, linear))
        return losses 

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import minimum [as 别名]
def _huber_loss(labels, predictions, mask, config):
        """ Huber loss according to masking"""
        delta = config.huber_delta
        predictions = math_ops.to_float(predictions)
        labels = math_ops.to_float(labels)
        predictions.get_shape().assert_is_compatible_with(labels.get_shape())
        error = math_ops.subtract(predictions, labels)
        abs_error = math_ops.abs(error)
        quadratic = math_ops.minimum(abs_error, delta)
        # The following expression is the same in value as
        # tf.maximum(abs_error - delta, 0), but importantly the gradient for the
        # expression when abs_error == delta is 0 (for tf.maximum it would be 1).
        # This is necessary to avoid doubling the gradient, since there is already a
        # nonzero contribution to the gradient from the quadratic term.
        linear = math_ops.subtract(abs_error, quadratic)
        losses = math_ops.add(
            math_ops.multiply(
                ops.convert_to_tensor(0.5, dtype=quadratic.dtype),
                math_ops.multiply(quadratic, quadratic)),
            math_ops.multiply(delta, linear))
        huber_loss = tf.reduce_sum(losses) / tf.reduce_sum(mask)
        return huber_loss 

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import minimum [as 别名]
def rotate90(bboxes, xs, ys, k):
#     bboxes = tf.Print(bboxes, [bboxes], 'before rotate',summarize = 100)
    ymin, xmin, ymax, xmax = [bboxes[:, i] for i in range(4)]
    xmin, ymin = tf_rotate_point_by_90(xmin, ymin, k)
    xmax, ymax = tf_rotate_point_by_90(xmax, ymax, k)
    
    new_xmin = tf.minimum(xmin, xmax)
    new_xmax = tf.maximum(xmin, xmax)
    
    new_ymin = tf.minimum(ymin, ymax)
    new_ymax = tf.maximum(ymin, ymax)
    
    bboxes = tf.stack([new_ymin, new_xmin, new_ymax, new_xmax])
    bboxes = tf.transpose(bboxes)

    xs, ys = tf_rotate_point_by_90(xs, ys, k)
    return bboxes, xs, ys 

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import minimum [as 别名]
def LRSchedule(global_step, d_model, warmup_steps=4000):
	if global_step is None:
		raise ValueError("global_step is required for learning_rate_schedule.")

	def deal_lr(global_step, d_model, warmup_steps):
		d_model = ops.convert_to_tensor(d_model, dtype=tf.float32)
		dtype = d_model.dtype
		warmup_steps = math_ops.cast(warmup_steps, dtype)

		global_step_recomp = math_ops.cast(global_step, dtype)
		arg1 = math_ops.rsqrt(global_step_recomp)
		arg2 = math_ops.multiply(global_step_recomp, math_ops.pow(warmup_steps, -1.5))

		return math_ops.multiply(math_ops.rsqrt(d_model), math_ops.minimum(arg1, arg2))

	return functools.partial(deal_lr, global_step, d_model, warmup_steps) 

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import minimum [as 别名]
def poincare_normalize(x, axis=1, epsilon=1e-5, name=None):
  """Project into the Poincare ball with norm <= 1.0 - epsilon.

  https://en.wikipedia.org/wiki/Poincare_ball_model

  Used in
  Poincare Embeddings for Learning Hierarchical Representations
  Maximilian Nickel, Douwe Kiela
  https://arxiv.org/pdf/1705.08039.pdf

  For a 1-D tensor with `axis = 0`, computes

                (x * (1 - epsilon)) / ||x||     if ||x|| > 1 - epsilon
      output =
                 x                              otherwise

  For `x` with more dimensions, independently normalizes each 1-D slice along
  dimension `axis`.

  Args:
    x: A `Tensor`.
    axis: Axis along which to normalize.  A scalar or a vector of integers.
    epsilon: A small deviation from the edge of the unit sphere for numerical
      stability.
    name: A name for this operation (optional).

  Returns:
    A `Tensor` with the same shape as `x`.
  """
  with ops.name_scope(name, 'poincare_normalize', [x]) as name:
    x = ops.convert_to_tensor(x, name='x')
    square_sum = math_ops.reduce_sum(math_ops.square(x), axis, keepdims=True)
    x_inv_norm = math_ops.rsqrt(square_sum)
    x_inv_norm = math_ops.minimum((1. - epsilon) * x_inv_norm, 1.)
    return math_ops.multiply(x, x_inv_norm, name=name) 

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import minimum [as 别名]
def _adaptive_max_norm(norm, std_factor, decay, global_step, epsilon, name):
  """Find max_norm given norm and previous average."""
  with vs.variable_scope(name, "AdaptiveMaxNorm", [norm]):
    log_norm = math_ops.log(norm + epsilon)

    def moving_average(name, value, decay):
      moving_average_variable = vs.get_variable(
          name,
          shape=value.get_shape(),
          dtype=value.dtype,
          initializer=init_ops.zeros_initializer(),
          trainable=False)
      return moving_averages.assign_moving_average(
          moving_average_variable, value, decay, zero_debias=False)

    # quicker adaptation at the beginning
    if global_step is not None:
      n = math_ops.cast(global_step, dtypes.float32)
      decay = math_ops.minimum(decay, n / (n + 1.))

    # update averages
    mean = moving_average("mean", log_norm, decay)
    sq_mean = moving_average("sq_mean", math_ops.square(log_norm), decay)

    variance = sq_mean - math_ops.square(mean)
    std = math_ops.sqrt(math_ops.maximum(epsilon, variance))
    max_norms = math_ops.exp(mean + std_factor * std)
    return max_norms, mean 

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import minimum [as 别名]
def resize_audio_with_crop_or_pad(image, target_height, target_width,
                                  dynamic_shape=False):
  image = tf.convert_to_tensor(image, name='audio')
  original_height,  _ =     _ImageDimensions(image, dynamic_shape=dynamic_shape)

  if target_height <= 0:
    raise ValueError('target_height must be > 0.')

  if dynamic_shape:
    max_ = math_ops.maximum
    min_ = math_ops.minimum
  else:
    max_ = max
    min_ = min

  height_diff = target_height - original_height
  offset_crop_height = max_(-height_diff // 2, 0)
  offset_pad_height = max_(height_diff // 2, 0)

  # Maybe crop if needed.
  cropped = crop_to_1d_bounding_box(image, offset_crop_height,
                                 min_(target_height, original_height),
                                 dynamic_shape=dynamic_shape)

  # Maybe pad if needed.
  resized = pad_to_1d_bounding_box(cropped, offset_pad_height, 
                                target_height, 
                                dynamic_shape=dynamic_shape)

  if resized.get_shape().ndims is None:
    raise ValueError('resized contains no shape.')
  if not resized.get_shape()[0].is_compatible_with(target_height):
    raise ValueError('resized height is not correct.')
  return resized


# In[5]: 

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import minimum [as 别名]
def _num_relevant(labels, k):
  """Computes number of relevant values for each row in labels.

  For labels with shape [D1, ... DN, num_labels], this is the minimum of
  `num_labels` and `k`.

  Args:
    labels: `int64` `Tensor` or `SparseTensor` with shape
      [D1, ... DN, num_labels], where N >= 1 and num_labels is the number of
      target classes for the associated prediction. Commonly, N=1 and `labels`
      has shape [batch_size, num_labels].
    k: Integer, k for @k metric.

  Returns:
    Integer `Tensor` of shape [D1, ... DN], where each value is the number of
    relevant values for that row.

  Raises:
    ValueError: if inputs have invalid dtypes or values.
  """
  if k < 1:
    raise ValueError('Invalid k=%s.' % k)
  with ops.name_scope(None, 'num_relevant', (labels,)) as scope:
    # For SparseTensor, calculate separate count for each row.
    labels = sparse_tensor.convert_to_tensor_or_sparse_tensor(labels)
    if isinstance(labels, sparse_tensor.SparseTensor):
      return math_ops.minimum(sets.set_size(labels), k, name=scope)

    # For dense Tensor, calculate scalar count based on last dimension, and
    # tile across labels shape.
    labels_shape = array_ops.shape(labels)
    labels_size = labels_shape[-1]
    num_relevant_scalar = math_ops.minimum(labels_size, k)
    return array_ops.fill(labels_shape[0:-1], num_relevant_scalar, name=scope) 

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import minimum [as 别名]
def clip_by_value(t, clip_value_min, clip_value_max,
                  name=None):
  """Clips tensor values to a specified min and max.

  Given a tensor `t`, this operation returns a tensor of the same type and
  shape as `t` with its values clipped to `clip_value_min` and `clip_value_max`.
  Any values less than `clip_value_min` are set to `clip_value_min`. Any values
  greater than `clip_value_max` are set to `clip_value_max`.

  Args:
    t: A `Tensor`.
    clip_value_min: A 0-D (scalar) `Tensor`, or a `Tensor` with the same shape
      as `t`. The minimum value to clip by.
    clip_value_max: A 0-D (scalar) `Tensor`, or a `Tensor` with the same shape
      as `t`. The maximum value to clip by.
    name: A name for the operation (optional).

  Returns:
    A clipped `Tensor`.

  Raises:
    ValueError: if the clip tensors would trigger array broadcasting
      that would make the returned tensor larger than the input.
  """
  with ops.name_scope(name, "clip_by_value",
                      [t, clip_value_min, clip_value_max]) as name:
    t = ops.convert_to_tensor(t, name="t")

    # Go through list of tensors, for each value in each tensor clip
    t_min = math_ops.minimum(t, clip_value_max)
    # Assert that the shape is compatible with the initial shape,
    # to prevent unintentional broadcasting.
    _ = t.shape.merge_with(t_min.shape)

    t_max = math_ops.maximum(t_min, clip_value_min, name=name)
    _ = t.shape.merge_with(t_max.shape)

  return t_max 

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import minimum [as 别名]
def clip_by_average_norm(t, clip_norm, name=None):
  """Clips tensor values to a maximum average L2-norm.

  Given a tensor `t`, and a maximum clip value `clip_norm`, this operation
  normalizes `t` so that its average L2-norm is less than or equal to
  `clip_norm`. Specifically, if the average L2-norm is already less than or
  equal to `clip_norm`, then `t` is not modified. If the average L2-norm is
  greater than `clip_norm`, then this operation returns a tensor of the same
  type and shape as `t` with its values set to:

  `t * clip_norm / l2norm_avg(t)`

  In this case, the average L2-norm of the output tensor is `clip_norm`.

  This operation is typically used to clip gradients before applying them with
  an optimizer.

  Args:
    t: A `Tensor`.
    clip_norm: A 0-D (scalar) `Tensor` > 0. A maximum clipping value.
    name: A name for the operation (optional).

  Returns:
    A clipped `Tensor`.
  """
  with ops.name_scope(name, "clip_by_average_norm", [t, clip_norm]) as name:
    t = ops.convert_to_tensor(t, name="t")

    # Calculate L2-norm per element, clip elements by ratio of clip_norm to
    # L2-norm per element
    n_element = math_ops.cast(array_ops.size(t), dtypes.float32)
    l2norm_inv = math_ops.rsqrt(
        math_ops.reduce_sum(t * t, math_ops.range(array_ops.rank(t))))
    tclip = array_ops.identity(
        t * clip_norm * math_ops.minimum(
            l2norm_inv * n_element, constant_op.constant(1.0) / clip_norm),
        name=name)

  return tclip 

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import minimum [as 别名]
def per_image_standardization(image):
  """Linearly scales `image` to have zero mean and unit norm.

  This op computes `(x - mean) / adjusted_stddev`, where `mean` is the average
  of all values in image, and
  `adjusted_stddev = max(stddev, 1.0/sqrt(image.NumElements()))`.

  `stddev` is the standard deviation of all values in `image`. It is capped
  away from zero to protect against division by 0 when handling uniform images.

  Args:
    image: 3-D tensor of shape `[height, width, channels]`.

  Returns:
    The standardized image with same shape as `image`.

  Raises:
    ValueError: if the shape of 'image' is incompatible with this function.
  """
  image = ops.convert_to_tensor(image, name='image')
  image = control_flow_ops.with_dependencies(
      _Check3DImage(image, require_static=False), image)
  num_pixels = math_ops.reduce_prod(array_ops.shape(image))

  image = math_ops.cast(image, dtype=dtypes.float32)
  image_mean = math_ops.reduce_mean(image)

  variance = (math_ops.reduce_mean(math_ops.square(image)) -
              math_ops.square(image_mean))
  variance = gen_nn_ops.relu(variance)
  stddev = math_ops.sqrt(variance)

  # Apply a minimum normalization that protects us against uniform images.
  min_stddev = math_ops.rsqrt(math_ops.cast(num_pixels, dtypes.float32))
  pixel_value_scale = math_ops.maximum(stddev, min_stddev)
  pixel_value_offset = image_mean

  image = math_ops.subtract(image, pixel_value_offset)
  image = math_ops.div(image, pixel_value_scale)
  return image 

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import minimum [as 别名]
def __call__(self, shape, dtype=None, partition_info=None):
    if dtype is None:
      dtype = self.dtype
    # Check the shape
    if len(shape) < 2:
      raise ValueError("The tensor to initialize must be "
                       "at least two-dimensional")
    # Flatten the input shape with the last dimension remaining
    # its original shape so it works for conv2d
    num_rows = 1
    for dim in shape[:-1]:
      num_rows *= dim
    num_cols = shape[-1]
    flat_shape = (num_rows, num_cols)

    # Generate a random matrix
    a = random_ops.random_normal(flat_shape, dtype=dtype, seed=self.seed)
    # Compute the qr factorization
    q, r = linalg_ops.qr(a, full_matrices=False)
    # Make Q uniform
    square_len = math_ops.minimum(num_rows, num_cols)
    d = array_ops.diag_part(r[:square_len, :square_len])
    ph = d / math_ops.abs(d)
    q *= ph
    # Pad zeros to Q (if rows smaller than cols)
    if num_rows < num_cols:
      padding = array_ops.zeros([num_rows, num_cols - num_rows], dtype=dtype)
      q = array_ops.concat([q, padding], 1)
    return self.gain * array_ops.reshape(q, shape) 

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import minimum [as 别名]
def argmin(x, axis=-1):
  """Returns the index of the minimum value along an axis.

  Arguments:
      x: Tensor or variable.
      axis: axis along which to perform the reduction.

  Returns:
      A tensor.
  """
  axis = _normalize_axis(axis, ndim(x))
  return math_ops.argmin(x, axis)