def testClipByNormClipped(self):
# Norm clipping when clip_norm < 5
with self.session(use_gpu=True):
x = constant_op.constant([-3.0, 0.0, 0.0, 4.0, 0.0, 0.0], shape=[2, 3])
# Norm of x = sqrt(3^2 + 4^2) = 5
np_ans = [[-2.4, 0.0, 0.0], [3.2, 0.0, 0.0]]
clip_norm = 4.0
ans = clip_ops.clip_by_norm(x, clip_norm)
tf_ans = self.evaluate(ans)
ans = clip_ops.clip_by_norm(x, clip_norm)
tf_ans_tensor = self.evaluate(ans)
self.assertAllClose(np_ans, tf_ans)
self.assertAllClose(np_ans, tf_ans_tensor)
def testClipByNormBadShape(self):
with self.test_session(use_gpu=True):
x = constant_op.constant([-3.0, 0.0, 0.0, 4.0, 0.0, 0.0], shape=[2, 3, 1])
# Use a nonsensical shape.
clip = constant_op.constant([1.0, 2.0])
with self.assertRaises(ValueError):
_ = clip_ops.clip_by_norm(x, clip)
def _testClipByNorm(self, inputs, max_norm, expected):
with self.test_session() as sess:
input_op = constant_op.constant(inputs)
clipped = clip_ops.clip_by_norm(input_op, max_norm)
check_op = numerics.add_check_numerics_ops()
result, _ = sess.run([clipped, check_op])
self.assertAllClose(result, expected)
def get_gradients(self, loss, params):
"""Returns gradients of `loss` with respect to `params`.
Arguments:
loss: Loss tensor.
params: List of variables.
Returns:
List of gradient tensors.
Raises:
ValueError: In case any gradient cannot be computed (e.g. if gradient
function not implemented).
"""
params = nest.flatten(params)
with backend.get_graph().as_default():
grads = gradients.gradients(loss, params)
for grad, param in zip(grads, params):
if grad is None:
raise ValueError("Variable {} has `None` for gradient. "
"Please make sure that all of your ops have a "
"gradient defined (i.e. are differentiable). "
"Common ops without gradient: "
"K.argmax, K.round, K.eval.".format(param))
if hasattr(self, "clipnorm"):
grads = [clip_ops.clip_by_norm(g, self.clipnorm) for g in grads]
if hasattr(self, "clipvalue"):
grads = [
clip_ops.clip_by_value(g, -self.clipvalue, self.clipvalue)
for g in grads
]
return grads
def get_gradients(self, loss, params):
"""Returns gradients of `loss` with respect to `params`.
Arguments:
loss: Loss tensor.
params: List of variables.
Returns:
List of gradient tensors.
Raises:
ValueError: In case any gradient cannot be computed (e.g. if gradient
function not implemented).
"""
loss = self._scale_loss(loss)
grads = gradients.gradients(loss, params)
if None in grads:
raise ValueError("An operation has `None` for gradient. "
"Please make sure that all of your ops have a "
"gradient defined (i.e. are differentiable). "
"Common ops without gradient: "
"K.argmax, K.round, K.eval.")
if hasattr(self, "clipnorm"):
grads = [clip_ops.clip_by_norm(g, self.clipnorm) for g in grads]
if hasattr(self, "clipvalue"):
grads = [
clip_ops.clip_by_value(g, -self.clipvalue, self.clipvalue)
for g in grads
]
return grads
def _clip_dense(self, var):
with self._maybe_colocate_with(var):
updated_var_value = array_ops.identity(var.ref())
normalized_var = clip_ops.clip_by_norm(
updated_var_value, self._max_norm, self._vars_to_clip_dims[var])
delta = updated_var_value - normalized_var
with ops.colocate_with(var):
return var.assign_sub(delta, use_locking=self._use_locking)
def maybe_normalize(x):
if max_norm is not None:
if x.get_shape().ndims is not None:
ndims = x.get_shape().ndims
else:
ndims = array_ops.size(array_ops.shape(x))
return clip_ops.clip_by_norm(x, max_norm, axes=list(range(1, ndims)))
return x
def _testClipIndexedSlicesByNorm(self, values, indices, shape, max_norm,
axes):
with self.cached_session() as sess:
values = constant_op.constant(values)
indices = constant_op.constant(indices)
shape = constant_op.constant(shape)
# IndexedSlices mode
indixed_slices = ops.IndexedSlices(values, indices, shape)
clipped = clip_ops.clip_by_norm(indixed_slices, max_norm, axes)
# clipped should be IndexedSlices
self.assertIsInstance(clipped, ops.IndexedSlices)
clipped = ops.convert_to_tensor(clipped)
# Tensor mode
dense_tensor = ops.convert_to_tensor(indixed_slices)
dense_clipped = clip_ops.clip_by_norm(dense_tensor, max_norm, axes)
result, expected = sess.run([clipped, dense_clipped])
self.assertAllClose(result, expected)
def testClipByNormNotClipped(self):
# No norm clipping when clip_norm >= 5
with self.test_session():
x = constant_op.constant([-3.0, 0.0, 0.0, 4.0, 0.0, 0.0], shape=[2, 3])
# Norm of x = sqrt(3^2 + 4^2) = 5
np_ans = [[-3.0, 0.0, 0.0], [4.0, 0.0, 0.0]]
clip_norm = 6.0
ans = clip_ops.clip_by_norm(x, clip_norm)
tf_ans = ans.eval()
self.assertAllClose(np_ans, tf_ans)
def testClipByNormClippedWithDim1(self):
# Norm clipping when clip_norm < 5
with self.session(use_gpu=True):
x = constant_op.constant([-3.0, 0.0, 0.0, 4.0, 0.0, 3.0], shape=[2, 3])
# Norm of x[0, :] = 3, x[1, :] = sqrt(3^2 + 4^2) = 5
np_ans = [[-3.0, 0.0, 0.0], [3.2, 0.0, 2.4]]
clip_norm = 4.0
ans = clip_ops.clip_by_norm(x, clip_norm, [1])
tf_ans = self.evaluate(ans)
self.assertAllClose(np_ans, tf_ans)
def testClipByNormZero(self):
# No norm clipping when norm = 0
with self.test_session(use_gpu=True):
x = constant_op.constant([0.0, 0.0, 0.0, 0.0, 0.0, 0.0], shape=[2, 3])
# Norm = 0, no changes
np_ans = [[0.0, 0.0, 0.0], [0.0, 0.0, 0.0]]
clip_norm = 6.0
ans = clip_ops.clip_by_norm(x, clip_norm)
tf_ans = ans.eval()
self.assertAllClose(np_ans, tf_ans)
def clip_gradient_norms(gradients_to_variables, max_norm):
"""Clips the gradients by the given value.
Args:
gradients_to_variables: A list of gradient to variable pairs (tuples).
max_norm: the maximum norm value.
Returns:
A list of clipped gradient to variable pairs.
"""
clipped_grads_and_vars = []
for grad, var in gradients_to_variables:
if grad is not None:
if isinstance(grad, ops.IndexedSlices):
tmp = clip_ops.clip_by_norm(grad.values, max_norm)
grad = ops.IndexedSlices(tmp, grad.indices, grad.dense_shape)
else:
grad = clip_ops.clip_by_norm(grad, max_norm)
clipped_grads_and_vars.append((grad, var))
return clipped_grads_and_vars
def testClipByNormNotClippedWithAxes(self):
# No norm clipping when clip_norm >= 5
with self.test_session(use_gpu=True):
x = constant_op.constant([-3.0, 0.0, 0.0, 4.0, 0.0, 3.0], shape=[2, 3])
# Norm of x[0, :] = 3, x[1, :] = sqrt(3^2 + 4^2) = 5
np_ans = [[-3.0, 0.0, 0.0], [4.0, 0.0, 3.0]]
clip_norm = 6.0
ans = clip_ops.clip_by_norm(x, clip_norm, [1])
tf_ans = ans.eval()
self.assertAllClose(np_ans, tf_ans)
def testClipByNormClippedWithDim0(self):
# Norm clipping when clip_norm < 5
with self.test_session(use_gpu=True):
x = constant_op.constant([-3.0, 0.0, 0.0, 4.0, 0.0, 3.0], shape=[2, 3])
# Norm of x[:, 0] = sqrt(3^2 + 4^2) = 5, x[:, 2] = 3
np_ans = [[-2.4, 0.0, 0.0], [3.2, 0.0, 3.0]]
clip_norm = 4.0
ans = clip_ops.clip_by_norm(x, clip_norm, [0])
tf_ans = ans.eval()
self.assertAllClose(np_ans, tf_ans)
def _compute_gradients(self, loss, var_list, grad_loss=None):
"""Compute gradients of `loss` for the variables in `var_list`.
This is the first part of `minimize()`. It returns a list
of (gradient, variable) pairs where "gradient" is the gradient
for "variable". Note that "gradient" can be a `Tensor`, an
`IndexedSlices`, or `None` if there is no gradient for the
given variable.
Args:
loss: A callable taking no arguments which returns the value to minimize.
var_list: list or tuple of `Variable` objects to update to minimize
`loss`, or a callable returning the list or tuple of `Variable` objects.
Use callable when the variable list would otherwise be incomplete before
`minimize` and the variables are created at the first time when `loss`
is called.
grad_loss: Optional. A `Tensor` holding the gradient computed for `loss`.
Returns:
A list of (gradient, variable) pairs. Variable is always present, but
gradient can be `None`.
Raises:
TypeError: If `var_list` contains anything else than `Variable` objects.
ValueError: If some arguments are invalid, or var_list is None.
"""
# TODO(josh11b): Test that we handle weight decay in a reasonable way.
with backprop.GradientTape() as tape:
if not callable(var_list):
tape.watch(var_list)
loss_value = loss()
if callable(var_list):
var_list = var_list()
var_list = nest.flatten(var_list)
grads = tape.gradient(loss_value, var_list, grad_loss)
if hasattr(self, "clipnorm"):
grads = [clip_ops.clip_by_norm(g, self.clipnorm) for g in grads]
if hasattr(self, "clipvalue"):
grads = [
clip_ops.clip_by_value(g, -self.clipvalue, self.clipvalue)
for g in grads
]
grads_and_vars = list(zip(grads, var_list))
self._assert_valid_dtypes([
v for g, v in grads_and_vars
if g is not None and v.dtype != dtypes.resource
])
return grads_and_vars
def testClipByAverageNormReplacedWithClipByNorm(self):
# Check clip_by_average_norm(t) is the same as
# clip_by_norm(t, clip_norm * tf.to_float(tf.size(t)))
with self.session(use_gpu=True):
x = constant_op.constant([-3.0, 0.0, 0.0, 4.0, 0.0, 0.0], shape=[2, 3])
# Average norm of x = sqrt(3^2 + 4^2) / 6 = 0.83333333
# expected answer [[-2.88, 0.0, 0.0], [3.84, 0.0, 0.0]]
clip_norm = constant_op.constant(0.8)
with_norm = clip_ops.clip_by_average_norm(x, clip_norm)
without_norm = clip_ops.clip_by_norm(
x, clip_norm * math_ops.to_float(array_ops.size(x)))
clip_by_average_norm_ans = self.evaluate(with_norm)
clip_by_norm_ans = self.evaluate(without_norm)
self.assertAllClose(clip_by_average_norm_ans, clip_by_norm_ans)
def maybe_normalize(x):
"""Normalizes the embeddings in x if max_norm is not None."""
if max_norm is None:
return x
static = True
ids_rank = ops.convert_to_tensor(ids).get_shape().ndims
if ids_rank is None:
ids_rank = array_ops.rank(ids)
static = False
x_rank = x.get_shape().ndims
if x_rank is None:
x_rank = array_ops.rank(x)
static = False
return clip_ops.clip_by_norm(
x, max_norm,
axes=list(range(ids_rank, x_rank)) if static
else math_ops.range(ids_rank, x_rank))
def _clip_sparse(self, grad, var):
assert isinstance(grad, ops.IndexedSlices)
clip_dims = self._vars_to_clip_dims[var]
if 0 in clip_dims:
logging.warning("Clipping norm across dims %s for %s is inefficient "
"when including sparse dimension 0.", clip_dims,
var.op.name)
return self._clip_dense(var)
with ops.colocate_with(var):
var_subset = array_ops.gather(var.ref(), grad.indices)
with self._maybe_colocate_with(var):
normalized_var_subset = clip_ops.clip_by_norm(
var_subset, self._max_norm, clip_dims)
delta = ops.IndexedSlices(
var_subset - normalized_var_subset, grad.indices, grad.dense_shape)
with ops.colocate_with(var):
return var.scatter_sub(delta, use_locking=self._use_locking)
def _clip_gradients(self, grads):
"""Clip gradients according to the clipnorm and clipvalue attributes."""
if self.clipnorm is not None:
if distribute_ctx.has_strategy():
raise ValueError("Gradient clipping in the optimizer "
"(by setting clipnorm or clipvalue) is currently "
"unsupported when using a distribution strategy.")
grads = [None if g is None else clip_ops.clip_by_norm(g, self.clipnorm)
for g in grads]
if self.clipvalue is not None:
if distribute_ctx.has_strategy():
raise ValueError("Gradient clipping in the optimizer "
"(by setting clipnorm or clipvalue) is currently "
"unsupported when using a distribution strategy.")
v = self.clipvalue
grads = [
None if g is None else clip_ops.clip_by_value(g, -v, v) for g in grads
]
return grads
def _clip(params, ids, max_norm):
def _rank(x):
rank = ops.convert_to_tensor(x).get_shape().ndims
if rank:
return rank, True
else:
return array_ops.rank(x), False
if max_norm is None:
return params
ids_rank, ids_static = _rank(ids)
params_rank, params_static = _rank(params)
return clip_ops.clip_by_norm(
params,
max_norm,
axes=(list(range(ids_rank, params_rank))
if ids_static and params_static else math_ops.range(
ids_rank, params_rank)),
)
def _clip(params, ids, max_norm):
"""Helper function for _embedding_lookup_and_transform.
This function optionally clips embeddings to an l2-norm of max_norm.
Args:
params: A `Tensor` of embeddings retrieved by `gather`.
ids: The `ids` argument that was passed to `gather`.
max_norm: If provided, the embeddings are l2-normalized to the value of
max_norm.
Returns:
A `Tensor` with the same type as `params`.
"""
def _rank(x):
"""Helper function to retrieve the rank of a tensor.
Args:
x: Something convertible to `Tensor`.
Returns:
Either a pair `(rank, True)` where `rank` is an integer or a pair
`(rank, False)` where `rank` is an integer `Tensor`. In either case,
`rank` is the rank of `x`.
"""
rank = ops.convert_to_tensor(x).get_shape().ndims
if rank:
return rank, True
else:
return array_ops.rank(x), False
if max_norm is None:
return params
ids_rank, ids_static = _rank(ids)
params_rank, params_static = _rank(params)
return clip_ops.clip_by_norm(
params,
max_norm,
axes=(list(range(ids_rank, params_rank))
if ids_static and params_static
else math_ops.range(ids_rank, params_rank)))
def _clip(params, ids, max_norm):
"""Helper function for _embedding_lookup_and_transform.
This function optionally clips embeddings to an l2-norm of max_norm.
Args:
params: A `Tensor` of embeddings retrieved by `gather`.
ids: The `ids` argument that was passed to `gather`.
max_norm: If not `None`, each embedding is clipped if its l2-norm is
larger than this value.
Returns:
A `Tensor` with the same type as `params`.
"""
def _rank(x):
"""Helper function to retrieve the rank of a tensor.
Args:
x: Something convertible to `Tensor`.
Returns:
Either a pair `(rank, True)` where `rank` is an integer or a pair
`(rank, False)` where `rank` is an integer `Tensor`. In either case,
`rank` is the rank of `x`.
"""
rank = ops.convert_to_tensor(x).get_shape().ndims
if rank:
return rank, True
else:
return array_ops.rank(x), False
if max_norm is None:
return params
ids_rank, ids_static = _rank(ids)
params_rank, params_static = _rank(params)
return clip_ops.clip_by_norm(
params,
max_norm,
axes=(list(range(ids_rank, params_rank))
if ids_static and params_static
else math_ops.range(ids_rank, params_rank)))
def get_gradients_for_keras(optimizer, loss, params):
from tensorflow.python.util import nest
from tensorflow.python.keras import backend
from tensorflow.python.ops import gradients
from tensorflow.python.ops import clip_ops
from tensorflow.python.keras.optimizers import TFOptimizer
params = nest.flatten(params)
if isinstance(optimizer, TFOptimizer):
scope_name = optimizer.optimizer._name
else:
scope_name = optimizer._name
with backend.get_graph().as_default(), backend.name_scope(scope_name + "/gradients"):
grads = gradients.gradients(loss, params)
all_reduced_grads = []
for grad, param in zip(grads, params):
if grad is None:
raise ValueError("Variable {} has `None` for gradient. "
"Please make sure that all of your ops have a "
"gradient defined (i.e. are differentiable). "
"Common ops without gradient: "
"K.argmax, K.round, K.eval.".format(param))
grad = process_grad(grad)
with tf.control_dependencies([param]):
grad_i = tf.identity(grad, name="zoo_identity_op_for_grad")
all_reduced_grads.append(grad_i)
grads = all_reduced_grads
if hasattr(optimizer, "clipnorm"):
grads = [clip_ops.clip_by_norm(g, optimizer.clipnorm) for g in grads]
if hasattr(optimizer, "clipvalue"):
grads = [
clip_ops.clip_by_value(g, -optimizer.clipvalue, optimizer.clipvalue)
for g in grads
]
return grads
def train_one_sample(self, space_sample, reward):
self.reset()
with tf.GradientTape() as tape:
self.reset()
self.calc_log_prob(space_sample)
if self.entropy_weight is not None:
self.reward += self.entropy_weight * self.entropy
self.baseline = self.baseline * self.baseline_decay + reward * (
1 - self.baseline_decay)
loss = self.log_prob * (reward - self.baseline)
print(f'Reward: {reward}, Loss: {loss}')
# loss += skip_weight * self.sample_skip_penalty
grads = tape.gradient(loss, self.trainable_variables)
if hasattr(self, "clipnorm"):
grads = [clip_ops.clip_by_norm(g, self.clipnorm) for g in grads]
if hasattr(self, "clipvalue"):
grads = [
clip_ops.clip_by_value(g, -self.clipvalue, self.clipvalue)
for g in grads
]
self.optimizer.apply_gradients(zip(grads, self.trainable_variables))
return loss
def _gather_and_clip(params, ids, max_norm, name=None):
"""Helper function for _embedding_lookup_and_transform.
This function gathers embeddings from a single tensor. The gather deals with
resource variables specially. The embeddings are clipped to an l2-norm of
max_norm if provided.
Args:
params: A `Tensor` of embeddings.
ids: A `Tensor` indexing the embeddings to be retrieved from `params`.
max_norm: If provided, embedding values are l2-normalized to the value of
max_norm.
name: A name for the operation (optional).
Returns:
A `Tensor` with the same type as `params`.
"""
if isinstance(params, resource_variable_ops.ResourceVariable):
embs = params.sparse_read(ids, name=name)
else:
embs = array_ops.gather(params, ids, name=name)
if max_norm is None:
return embs
static = True
ids_rank = ops.convert_to_tensor(ids).get_shape().ndims
if ids_rank is None:
ids_rank = array_ops.rank(ids)
static = False
embs_rank = embs.get_shape().ndims
if embs_rank is None:
embs_rank = array_ops.rank(embs)
static = False
return clip_ops.clip_by_norm(
embs,
max_norm,
axes=list(range(ids_rank, embs_rank))
if static else math_ops.range(ids_rank, embs_rank))
def _gather_and_clip(params, ids, max_norm, name=None):
"""Helper function for _embedding_lookup_and_transform.
This function gathers embeddings from a single tensor. The gather deals with
resource variables specially. The embeddings are clipped to an l2-norm of
max_norm if provided.
Args:
params: A `Tensor` of embeddings.
ids: A `Tensor` indexing the embeddings to be retrieved from `params`.
max_norm: If provided, embedding values are l2-normalized to the value of
max_norm.
name: A name for the operation (optional).
Returns:
A `Tensor` with the same type as `params`.
"""
if isinstance(params, resource_variable_ops.ResourceVariable):
embs = params.sparse_read(ids, name=name)
else:
embs = array_ops.gather(params, ids, name=name)
if max_norm is None:
return embs
static = True
ids_rank = ops.convert_to_tensor(ids).get_shape().ndims
if ids_rank is None:
ids_rank = array_ops.rank(ids)
static = False
embs_rank = embs.get_shape().ndims
if embs_rank is None:
embs_rank = array_ops.rank(embs)
static = False
return clip_ops.clip_by_norm(
embs,
max_norm,
axes=list(range(ids_rank, embs_rank))
if static else math_ops.range(ids_rank, embs_rank))
def get_gradients(self, loss, params):
"""Returns gradients of `loss` with respect to `params`.
Arguments:
loss: Loss tensor.
params: List of variables.
Returns:
List of gradient tensors.
Raises:
ValueError: In case any gradient cannot be computed (e.g. if gradient
function not implemented).
"""
params = nest.flatten(params)
with backend.get_graph().as_default(), backend.name_scope(
self._name + "/gradients"):
grads = gradients.gradients(loss, params)
for grad, param in zip(grads, params):
if grad is None:
raise ValueError(
"Variable {} has `None` for gradient. "
"Please make sure that all of your ops have a "
"gradient defined (i.e. are differentiable). "
"Common ops without gradient: "
"K.argmax, K.round, K.eval.".format(param))
if hasattr(self, "clipnorm"):
grads = [
clip_ops.clip_by_norm(g, self.clipnorm) for g in grads
]
if hasattr(self, "clipvalue"):
grads = [
clip_ops.clip_by_value(g, -self.clipvalue, self.clipvalue)
for g in grads
]
return grads
def _resource_apply_dense(self, grad, var):
step, beta1_power, beta2_power = self._get_beta_accumulators()
beta1_power = math_ops.cast(beta1_power, var.dtype.base_dtype)
beta2_power = math_ops.cast(beta2_power, var.dtype.base_dtype)
lr_t = math_ops.cast(self._lr_t, var.dtype.base_dtype)
if self._initial_total_steps > 0:
total_steps = math_ops.cast(self._total_steps_t,
var.dtype.base_dtype)
warmup_proportion = math_ops.cast(self._warmup_proportion_t,
var.dtype.base_dtype)
min_lr = math_ops.cast(self._min_lr_t, var.dtype.base_dtype)
warmup_steps = total_steps * warmup_proportion
decay_steps = math_ops.maximum(total_steps - warmup_steps, 1)
decay_rate = (min_lr - lr_t) / decay_steps
lr_t = tf.compat.v1.where(
step <= warmup_steps,
lr_t * (step / warmup_steps),
lr_t + decay_rate *
math_ops.minimum(step - warmup_steps, decay_steps),
)
beta1_t = math_ops.cast(self._beta1_t, var.dtype.base_dtype)
beta2_t = math_ops.cast(self._beta2_t, var.dtype.base_dtype)
epsilon_t = math_ops.cast(self._epsilon_t, var.dtype.base_dtype)
v = self.get_slot(var, "v")
if self.clip_gradients:
clipVal = math_ops.sqrt(
tf.reduce_sum(input_tensor=v) /
(1.0 -
beta2_power)) * self.clip_multiplier_t + self.clip_epsilon_t
grad = clip_ops.clip_by_norm(grad, clipVal)
sma_inf = 2.0 / (1.0 - beta2_t) - 1.0
sma_t = sma_inf - 2.0 * step * beta2_power / (1.0 - beta2_power)
m = self.get_slot(var, "m")
v_t = state_ops.assign(v,
beta2_t * v +
(1.0 - beta2_t) * math_ops.square(grad),
use_locking=self._use_locking)
v_corr_t = math_ops.sqrt(v_t / (1.0 - beta2_power)) + epsilon_t
grad_corr = grad / v_corr_t
m_t = state_ops.assign(m,
beta1_t * m + (1.0 - beta1_t) * grad_corr,
use_locking=self._use_locking)
m_corr_t = m_t / (1.0 - beta1_power)
r_t = math_ops.sqrt((sma_t - 4.0) / (sma_inf - 4.0) * (sma_t - 2.0) /
(sma_inf - 2.0) * sma_inf / sma_t)
var_t = tf.compat.v1.where(sma_t >= 5.0, r_t * m_corr_t, m_corr_t)
if var in self.reg_vars:
if self._initial_weight_decay > 0.0:
var_t += math_ops.cast(self._weight_decay_t,
var.dtype.base_dtype) * var
if self._L1_decay > 0.0:
var_t += math_ops.cast(
self._L1_decay, var.dtype.base_dtype) * math_ops.sign(var)
with tf.control_dependencies([var_t]):
var_update = state_ops.assign_sub(var,
lr_t * var_t,
use_locking=self._use_locking)
updates = [var_update, m_t, v_t]
return control_flow_ops.group(*updates)
def testClipByNormGradientZeros(self):
with self.session(use_gpu=True):
x = array_ops.zeros([3])
b = clip_ops.clip_by_norm(x, 1.)
grad, = gradients_impl.gradients(b, x)
self.assertAllEqual(grad, [1., 1., 1.])
def compute_gradients(self, loss, var_list=None,
gate_gradients=GATE_OP,
aggregation_method=None,
colocate_gradients_with_ops=False,
grad_loss=None, stop_gradients=None,
scale_loss_by_num_towers=None):
"""Compute gradients of `loss` for the variables in `var_list`.
This is the first part of `minimize()`. It returns a list
of (gradient, variable) pairs where "gradient" is the gradient
for "variable". Note that "gradient" can be a `Tensor`, an
`IndexedSlices`, or `None` if there is no gradient for the
given variable.
Args:
loss: A callable taking no arguments which returns the value to minimize.
var_list: list or tuple of `Variable` objects to update to minimize
`loss`, or a callable returning the list or tuple of `Variable` objects.
Use callable when the variable list would otherwise be incomplete before
`minimize` and the variables are created at the first time when `loss`
is called.
grad_loss: Optional. A `Tensor` holding the gradient computed for `loss`.
stop_gradients: Optional. A Tensor or list of tensors not to differentiate
through.
scale_loss_by_num_towers: Optional boolean. If true, scale the loss
down by the number of towers. By default, auto-detects whether this
is needed.
Returns:
A list of (gradient, variable) pairs. Variable is always present, but
gradient can be `None`.
Raises:
TypeError: If `var_list` contains anything else than `Variable` objects.
ValueError: If some arguments are invalid.
RuntimeError: If called with eager execution enabled and `loss` is
not callable.
@compatibility(eager)
When eager execution is enabled, `gate_gradients`, `aggregation_method`,
and `colocate_gradients_with_ops` are ignored.
@end_compatibility
"""
# TODO(josh11b): Test that we handle weight decay in a reasonable way.
with backprop.GradientTape() as tape:
if not callable(var_list):
tape.watch(var_list)
loss_value = loss()
if callable(var_list):
var_list = var_list()
var_list = nest.flatten(var_list)
grads = tape.gradient(loss_value, var_list, grad_loss)
if hasattr(self, "clipnorm"):
grads = [clip_ops.clip_by_norm(g, self.clipnorm) for g in grads]
if hasattr(self, "clipvalue"):
grads = [
clip_ops.clip_by_value(g, -self.clipvalue, self.clipvalue)
for g in grads
]
grads_and_vars = list(zip(grads, var_list))
self._assert_valid_dtypes(
[v for g, v in grads_and_vars
if g is not None and v.dtype != dtypes.resource])
return grads_and_vars
def _testClipTensorByNorm(self, inputs, max_norm, expected):
input_op = constant_op.constant(inputs)
clipped = clip_ops.clip_by_norm(input_op, max_norm)
check_op = numerics.add_check_numerics_ops()
result, _ = self.evaluate([clipped, check_op])
self.assertAllClose(result, expected)
def _apply_sparse_shared(self, grad, var, indices, scatter_add):
step, beta1_power, beta2_power = self._get_beta_accumulators()
beta1_power = math_ops.cast(beta1_power, var.dtype.base_dtype)
beta2_power = math_ops.cast(beta2_power, var.dtype.base_dtype)
lr_t = math_ops.cast(self._lr_t, var.dtype.base_dtype)
if self._initial_total_steps > 0:
total_steps = math_ops.cast(self._total_steps_t,
var.dtype.base_dtype)
warmup_proportion = math_ops.cast(self._warmup_proportion_t,
var.dtype.base_dtype)
min_lr = math_ops.cast(self._min_lr_t, var.dtype.base_dtype)
warmup_steps = total_steps * warmup_proportion
decay_steps = math_ops.maximum(total_steps - warmup_steps, 1)
decay_rate = (min_lr - lr_t) / decay_steps
lr_t = tf.compat.v1.where(
step <= warmup_steps,
lr_t * (step / warmup_steps),
lr_t + decay_rate *
math_ops.minimum(step - warmup_steps, decay_steps),
)
beta1_t = math_ops.cast(self._beta1_t, var.dtype.base_dtype)
beta2_t = math_ops.cast(self._beta2_t, var.dtype.base_dtype)
epsilon_t = math_ops.cast(self._epsilon_t, var.dtype.base_dtype)
v = self.get_slot(var, "v")
if self.clip_gradients:
clipVal = math_ops.sqrt(
tf.reduce_sum(input_tensor=v) /
(1.0 -
beta2_power)) * self.clip_multiplier_t + self.clip_epsilon_t
grad = clip_ops.clip_by_norm(grad, clipVal)
sma_inf = 2.0 / (1.0 - beta2_t) - 1.0
sma_t = sma_inf - 2.0 * step * beta2_power / (1.0 - beta2_power)
m = self.get_slot(var, "m")
m_scaled_g_values = grad * (1 - beta1_t)
m_t = state_ops.assign(m, m * beta1_t, use_locking=self._use_locking)
with ops.control_dependencies([m_t]):
m_t = scatter_add(m, indices, m_scaled_g_values)
m_corr_t = m_t / (1.0 - beta1_power)
v_scaled_g_values = (grad * grad) * (1 - beta2_t)
v_t = state_ops.assign(v, v * beta2_t, use_locking=self._use_locking)
with ops.control_dependencies([v_t]):
v_t = scatter_add(v, indices, v_scaled_g_values)
if self._amsgrad:
vhat = self.get_slot(var, 'vhat')
vhat_t = state_ops.assign(vhat,
math_ops.maximum(vhat, v_t),
use_locking=self._use_locking)
v_corr_t = math_ops.sqrt(vhat_t / (1.0 - beta2_power)) + epsilon_t
else:
v_corr_t = math_ops.sqrt(v_t / (1.0 - beta2_power)) + epsilon_t
r_t = math_ops.sqrt((sma_t - 4.0) / (sma_inf - 4.0) * (sma_t - 2.0) /
(sma_inf - 2.0) * sma_inf / sma_t)
var_t = tf.compat.v1.where(sma_t >= 5.0, r_t * m_corr_t / v_corr_t,
m_corr_t)
if var in self.reg_vars:
if self._initial_weight_decay > 0.0:
var_t += math_ops.cast(self._weight_decay_t,
var.dtype.base_dtype) * var
if self._L1_decay > 0.0:
var_t += math_ops.cast(
self._L1_decay, var.dtype.base_dtype) * math_ops.sign(var)
var_update = state_ops.assign_sub(var,
lr_t * var_t,
use_locking=self._use_locking)
updates = [var_update, m_t, v_t]
if self._amsgrad:
updates.append(vhat_t)
return control_flow_ops.group(*updates)
def _clip_gradients_seperate_norm(grads_and_vars, clip_gradients): """Clips gradients by global norm.""" gradients, variables = zip(*grads_and_vars) clipped_gradients = [clip_ops.clip_by_norm(grad, clip_gradients) for grad in gradients] return list(zip(clipped_gradients, variables))
def build_multi_tower_graph(images,
sketches,
images_d,
image_paired_class_ids,
image_paired_class_ids_d,
text_vocab_indiceses,
LSTM_hybrid,
vocab_size,
batch_size,
num_gpu,
batch_portion,
training,
learning_rates,
counter,
max_iter_step,
ld=10,
data_format='NCHW',
distance_map=True,
optimizer='Adam',
block_type='MRU'):
"""
:param images: [batch_size, 3, H, W]
:param sketches: [batch_size, 3, H, W]
:param images_d: [batch_size, 3, H, W]
:param image_paired_class_ids: [batch_size, ], class_number
:param image_paired_class_ids_d: [batch_size, ]
:param text_vocab_indiceses: [batch_size, 15]
:return:
"""
models.set_param(data_format=data_format)
with tf.device('/cpu:0'):
images_list = split_inputs(images, batch_size, batch_portion,
num_gpu) # [num_gpu, [N, C, H, W]]
images_d_list = split_inputs(images_d, batch_size, batch_portion,
num_gpu)
sketches_list = split_inputs(sketches, batch_size, batch_portion,
num_gpu)
image_paired_class_ids_list = split_inputs(image_paired_class_ids,
batch_size, batch_portion,
num_gpu)
image_paired_class_ids_d_list = split_inputs(image_paired_class_ids_d,
batch_size, batch_portion,
num_gpu)
text_vocab_indiceses_list = split_inputs(text_vocab_indiceses,
batch_size, batch_portion,
num_gpu)
lr_g = learning_rates['generator']
lr_d = learning_rates['discriminator']
optimizer = get_optimizer(optimizer)
decay = tf.maximum(
0.2, 1. - (tf.cast(counter, tf.float32) / max_iter_step * 0.9))
tf.summary.scalar('learning_rate_g', lr_g * decay)
optim_g = optimizer(learning_rate=lr_g * decay)
optim_d = optimizer(learning_rate=lr_d * decay)
tower_grads_g = []
tower_grads_d = []
for i in range(num_gpu):
with tf.name_scope('%s_%d' % ('GPU', i)) as scope:
loss_g, loss_d, grad_g, grad_d \
= build_single_graph(images_list[i],
sketches_list[i],
images_d_list[i],
image_paired_class_ids_list[i],
image_paired_class_ids_d_list[i],
text_vocab_indiceses_list[i],
batch_size * batch_portion[i],
training,
LSTM_hybrid=LSTM_hybrid,
vocab_size=vocab_size,
ld=ld, data_format=data_format,
distance_map=distance_map,
optim_g=optim_g,
optim_d=optim_d,
block_type=block_type)
tower_grads_g.append(grad_g)
tower_grads_d.append(grad_d)
assert len(tower_grads_g) == len(tower_grads_d)
if len(tower_grads_d) == 1:
ave_grad_g = grad_g
ave_grad_d = grad_d
else:
ave_grad_g, ave_grad_d = average_gradients(
(tower_grads_g, tower_grads_d))
# Apply gradients
tf.get_variable_scope(
)._reuse = False # Hack to force initialization of optimizer variables
if Config.sn:
# Get the update ops
spectral_norm_update_ops = tf.get_collection(
Config.SPECTRAL_NORM_UPDATE_OPS)
else:
spectral_norm_update_ops = [tf.no_op()]
assign_ops = tf.no_op()
# Clip gradients if using WGAN/DRAGAN
global_grad_norm_G = None
global_grad_norm_G_clipped = None
global_grad_norm_D = None
global_grad_norm_D_clipped = None
if not Config.sn:
max_grad_norm_G = 50.
max_grad_norm_D = 100.
hard_clip_norm_G = 5.
hard_clip_norm_D = 10.
ave_grad_g_tensors, ave_grad_g_vars = list(zip(*ave_grad_g))
global_grad_norm_G = clip_ops.global_norm(ave_grad_g_tensors)
ave_grad_g_tensors, _ = clip_ops.clip_by_global_norm(
ave_grad_g_tensors, max_grad_norm_G, global_grad_norm_G)
ave_grad_g_tensors = [
clip_ops.clip_by_norm(t, hard_clip_norm_G)
for t in ave_grad_g_tensors
]
ave_grad_g = list(zip(ave_grad_g_tensors, ave_grad_g_vars))
ave_grad_d_tensors, ave_grad_d_vars = list(zip(*ave_grad_d))
global_grad_norm_D = clip_ops.global_norm(ave_grad_d_tensors)
ave_grad_d_tensors, _ = clip_ops.clip_by_global_norm(
ave_grad_d_tensors, max_grad_norm_D, global_grad_norm_D)
ave_grad_d_tensors = [
clip_ops.clip_by_norm(t, hard_clip_norm_D)
for t in ave_grad_d_tensors
]
ave_grad_d = list(zip(ave_grad_d_tensors, ave_grad_d_vars))
with tf.control_dependencies(spectral_norm_update_ops):
opt_g = optimize(ave_grad_g,
optim_g,
None,
'gradient_norm',
global_norm=global_grad_norm_G,
global_norm_clipped=global_grad_norm_G_clipped,
appendix='_G')
opt_d = optimize(ave_grad_d,
optim_d,
None,
'gradient_norm',
global_norm=global_grad_norm_D,
global_norm_clipped=global_grad_norm_D_clipped,
appendix='_D')
summaries = gather_summaries()
loss_g, loss_d = gather_losses()
# Generator output from last tower
return opt_g, opt_d, loss_g, loss_d, summaries
def testClipByNormGradientZeros(self):
with self.session(use_gpu=True):
x = array_ops.zeros([3])
b = clip_ops.clip_by_norm(x, 1.)
grad, = gradients_impl.gradients(b, x)
self.assertAllEqual(grad.eval(), [1., 1., 1.])
