def decode(self, labeled_tensor):
"""Reshape the input to the original shape.
This is the inverse of encode.
Encode must have been called at least once prior to this method being
called.
Args:
labeled_tensor: The input tensor.
Returns:
The input reshaped to the original shape.
Raises:
ValueError: If this method was called before encode was called.
"""
if self._existing_axes is None:
raise ValueError('decode called before encode')
with tf_ops.name_scope(self._name, 'lt_reshape_decode',
[labeled_tensor]) as scope:
labeled_tensor = core.convert_to_labeled_tensor(labeled_tensor)
new_axis_names = [
axis
if isinstance(axis, string_types) else core.as_axis(axis).name
for axis in self._new_axes
]
return ops.reshape(labeled_tensor,
new_axis_names,
self._existing_axes,
name=scope)
def constant(value, dtype=None, axes=None, name=None):
"""Creates a constant tensor.
If `axes` includes any strings, shape is inferred from `value`. Otherwise,
the sizes of the given `axes` are used to set `shape` for `tf.constant`.
See tf.constant for more details.
Args:
value: The input tensor.
dtype: The type of the returned tensor.
axes: Optional Axes, list of strings or list of objects coercible to Axis
objects. By default, axes are assumed to be an empty list (i.e., `value`
is treated as a scalar).
name: Optional op name.
Returns:
The tensor with elements set to zero.
"""
with ops.name_scope(name, 'lt_constant', [value]) as scope:
if axes is None:
axes = []
if isinstance(axes, core.Axes):
axes = axes.values()
if any(isinstance(ax, string_types) for ax in axes):
# need to infer shape
shape = None
else:
# axes already indicate shape
axes = [core.as_axis(a) for a in axes]
shape = [a.size for a in axes]
op = array_ops.constant(value, dtype=dtype, shape=shape, name=scope)
return core.LabeledTensor(op, axes)
def reshape(labeled_tensor, existing_axes, new_axes, name=None):
"""Reshape specific axes of a LabeledTensor.
Non-indicated axes remain in their original locations.
Args:
labeled_tensor: The input tensor.
existing_axes: List of axis names found on the input tensor. These must
appear sequentially in the list of axis names on the input. In other
words, they must be a valid slice of `list(labeled_tensor.axes.keys())`.
new_axes: List of strings, tuples of (axis_name, axis_value) or Axis objects
providing new axes with which to replace `existing_axes` in the reshaped
result. At most one element of `new_axes` may be a string, indicating an
axis with unknown size.
name: Optional op name.
Returns:
The reshaped LabeledTensor.
Raises:
ValueError: If `existing_axes` are not all axes on the input, or if more
than one of `new_axes` has unknown size.
AxisOrderError: If `existing_axes` are not a slice of axis names on the
input.
"""
with ops.name_scope(name, 'lt_reshape', [labeled_tensor]) as scope:
labeled_tensor = core.convert_to_labeled_tensor(labeled_tensor)
original_axis_names = list(labeled_tensor.axes.keys())
existing_axes = list(existing_axes)
if not set(existing_axes) <= set(original_axis_names):
raise ValueError('existing_axes %r are not contained in the set of axis '
'names %r on the input labeled tensor' %
(existing_axes, original_axis_names))
start = original_axis_names.index(existing_axes[0])
stop = original_axis_names.index(existing_axes[-1]) + 1
if existing_axes != original_axis_names[start:stop]:
# We could support existing_axes that aren't a slice by using transpose,
# but that could lead to unpredictable performance consequences because
# transposes are not free in TensorFlow. If we did transpose
# automatically, the user might never realize that their data is being
# produced with the wrong order. (The later will occur with some frequency
# because of how broadcasting automatically choose axis order.)
# So for now we've taken the strict approach.
raise core.AxisOrderError(
'existing_axes %r are not a slice of axis names %r on the input '
'labeled tensor. Use `transpose` or `impose_axis_order` to reorder '
'axes on the input explicitly.' %
(existing_axes, original_axis_names))
if sum(isinstance(axis, string_types) for axis in new_axes) > 1:
raise ValueError(
'at most one axis in new_axes can have unknown size. All other '
'axes must have an indicated integer size or labels: %r' % new_axes)
original_values = list(labeled_tensor.axes.values())
axis_size = lambda axis: -1 if axis.size is None else axis.size
shape = [axis_size(axis) for axis in original_values[:start]]
for axis_ref in new_axes:
if isinstance(axis_ref, string_types):
shape.append(-1)
else:
axis = core.as_axis(axis_ref)
shape.append(axis_size(axis))
shape.extend(axis_size(axis) for axis in original_values[stop:])
reshaped_tensor = array_ops.reshape(
labeled_tensor.tensor, shape, name=scope)
axes = original_values[:start] + list(new_axes) + original_values[stop:]
return core.LabeledTensor(reshaped_tensor, axes)
def test_as_axis(self):
self.assertEqual(self.i_7, core.as_axis(('7', 7)))
self.assertEqual(self.i_7, core.as_axis(self.i_7))
def __init__(self, axes, dtype, default_value=None): self._axes = [core.as_axis(a) for a in axes] self._dtype = dtype self._default_value = default_value