def __init__(self, emb_dim, dim, num_input_words,
num_output_words, vocab,
**kwargs):
if emb_dim == 0:
emb_dim = dim
if num_input_words == 0:
num_input_words = vocab.size()
if num_output_words == 0:
num_output_words = vocab.size()
self._num_input_words = num_input_words
self._num_output_words = num_output_words
self._vocab = vocab
self._word_to_id = WordToIdOp(self._vocab)
children = []
self._main_lookup = LookupTable(self._num_input_words, emb_dim, name='main_lookup')
self._encoder_fork = Linear(emb_dim, 4 * dim, name='encoder_fork')
self._encoder_rnn = LSTM(dim, name='encoder_rnn')
self._decoder_fork = Linear(emb_dim, 4 * dim, name='decoder_fork')
self._decoder_rnn = LSTM(dim, name='decoder_rnn')
children.extend([self._main_lookup,
self._encoder_fork, self._encoder_rnn,
self._decoder_fork, self._decoder_rnn])
self._pre_softmax = Linear(dim, self._num_output_words)
self._softmax = NDimensionalSoftmax()
children.extend([self._pre_softmax, self._softmax])
super(LanguageModel, self).__init__(children=children, **kwargs)
def softmax_layer(h, y, x_mask, y_mask, lens, vocab_size, hidden_size,
boosting):
hidden_to_output = Linear(name='hidden_to_output',
input_dim=hidden_size,
output_dim=vocab_size)
initialize([hidden_to_output])
linear_output = hidden_to_output.apply(h)
linear_output.name = 'linear_output'
softmax = NDimensionalSoftmax()
#y_hat = softmax.apply(linear_output, extra_ndim=1)
#y_hat.name = 'y_hat'
cost_a = softmax.categorical_cross_entropy(y, linear_output, extra_ndim=1)
#produces correct average
cost_a = cost_a * y_mask
if boosting:
#boosting step, must divide by length here
lensMat = T.tile(lens, (y.shape[0], 1))
cost_a = cost_a / lensMat
#only count cost of correctly masked entries
cost = cost_a.sum() / y_mask.sum()
cost.name = 'cost'
return (linear_output, cost)
class ShallowFusionReadout(Readout):
def __init__(self, lm_costs_name, lm_weight,
normalize_am_weights=False,
normalize_lm_weights=False,
normalize_tot_weights=True,
am_beta=1.0,
**kwargs):
super(ShallowFusionReadout, self).__init__(**kwargs)
self.lm_costs_name = lm_costs_name
self.lm_weight = lm_weight
self.normalize_am_weights = normalize_am_weights
self.normalize_lm_weights = normalize_lm_weights
self.normalize_tot_weights = normalize_tot_weights
self.am_beta = am_beta
self.softmax = NDimensionalSoftmax()
self.children += [self.softmax]
@application
def readout(self, **kwargs):
lm_costs = -kwargs.pop(self.lm_costs_name)
if self.normalize_lm_weights:
lm_costs = self.softmax.log_probabilities(
lm_costs, extra_ndim=lm_costs.ndim - 2)
am_pre_softmax = self.am_beta * super(ShallowFusionReadout, self).readout(**kwargs)
if self.normalize_am_weights:
am_pre_softmax = self.softmax.log_probabilities(
am_pre_softmax, extra_ndim=am_pre_softmax.ndim - 2)
x = am_pre_softmax + self.lm_weight * lm_costs
if self.normalize_tot_weights:
x = self.softmax.log_probabilities(x, extra_ndim=x.ndim - 2)
return x
class ShallowFusionReadout(Readout):
def __init__(self,
lm_costs_name,
lm_weight,
normalize_am_weights=False,
normalize_lm_weights=False,
normalize_tot_weights=True,
am_beta=1.0,
**kwargs):
super(ShallowFusionReadout, self).__init__(**kwargs)
self.lm_costs_name = lm_costs_name
self.lm_weight = lm_weight
self.normalize_am_weights = normalize_am_weights
self.normalize_lm_weights = normalize_lm_weights
self.normalize_tot_weights = normalize_tot_weights
self.am_beta = am_beta
self.softmax = NDimensionalSoftmax()
self.children += [self.softmax]
@application
def readout(self, **kwargs):
lm_costs = -kwargs.pop(self.lm_costs_name)
if self.normalize_lm_weights:
lm_costs = self.softmax.log_probabilities(
lm_costs, extra_ndim=lm_costs.ndim - 2)
am_pre_softmax = self.am_beta * super(ShallowFusionReadout,
self).readout(**kwargs)
if self.normalize_am_weights:
am_pre_softmax = self.softmax.log_probabilities(
am_pre_softmax, extra_ndim=am_pre_softmax.ndim - 2)
x = am_pre_softmax + self.lm_weight * lm_costs
if self.normalize_tot_weights:
x = self.softmax.log_probabilities(x, extra_ndim=x.ndim - 2)
return x
def create_rnn(hidden_dim, vocab_dim,mode="rnn"):
# input
x = tensor.imatrix('inchar')
y = tensor.imatrix('outchar')
#
W = LookupTable(
name = "W1",
#dim = hidden_dim*4,
dim = hidden_dim,
length = vocab_dim,
weights_init = initialization.IsotropicGaussian(0.01),
biases_init = initialization.Constant(0)
)
if mode == "lstm":
# Long Short Term Memory
H = LSTM(
hidden_dim,
name = 'H',
weights_init = initialization.IsotropicGaussian(0.01),
biases_init = initialization.Constant(0.0)
)
else:
# recurrent history weight
H = SimpleRecurrent(
name = "H",
dim = hidden_dim,
activation = Tanh(),
weights_init = initialization.IsotropicGaussian(0.01)
)
#
S = Linear(
name = "W2",
input_dim = hidden_dim,
output_dim = vocab_dim,
weights_init = initialization.IsotropicGaussian(0.01),
biases_init = initialization.Constant(0)
)
A = NDimensionalSoftmax(
name = "softmax"
)
initLayers([W,H,S])
activations = W.apply(x)
hiddens = H.apply(activations)#[0]
activations2 = S.apply(hiddens)
y_hat = A.apply(activations2, extra_ndim=1)
cost = A.categorical_cross_entropy(y, activations2, extra_ndim=1).mean()
cg = ComputationGraph(cost)
#print VariableFilter(roles=[WEIGHT])(cg.variables)
#W1,H,W2 = VariableFilter(roles=[WEIGHT])(cg.variables)
layers = (x, W, H, S, A, y)
return cg, layers, y_hat, cost
def softmax_layer(h, y, frame_length, hidden_size):
hidden_to_output = Linear(name="hidden_to_output", input_dim=hidden_size, output_dim=frame_length)
initialize([hidden_to_output])
linear_output = hidden_to_output.apply(h)
linear_output.name = "linear_output"
softmax = NDimensionalSoftmax()
y_hat = softmax.apply(linear_output, extra_ndim=1)
y_hat.name = "y_hat"
cost = softmax.categorical_cross_entropy(y, linear_output, extra_ndim=1).mean()
cost.name = "cost"
return y_hat, cost
class NewSoftmaxEmitter(AbstractEmitter, Initializable, Random):
"""A softmax emitter for the case of integer outputs.
Interprets readout elements as energies corresponding to their indices.
Parameters
----------
initial_output : int or a scalar :class:`~theano.Variable`
The initial output.
"""
def __init__(self, initial_output=0, **kwargs):
super(NewSoftmaxEmitter, self).__init__(**kwargs)
self.initial_output = initial_output
self.softmax = NDimensionalSoftmax()
self.children = [self.softmax]
self.name = 'newbidirectional'
@application
def probs(self, readouts):
return self.softmax.apply(readouts, extra_ndim=readouts.ndim - 2)
@application
def emitProbs(self, readouts):
probs = self.probs(readouts)
batch_size = probs.shape[0]
self.pvals_flat = probs.reshape((batch_size, -1))
generated = self.theano_rng.multinomial(pvals=self.pvals_flat)
return self.pvals_flat
@application
def emit(self, readouts):
probs = self.probs(readouts)
batch_size = probs.shape[0]
self.pvals_flat = probs.reshape((batch_size, -1))
generated = self.theano_rng.multinomial(pvals=self.pvals_flat)
winning_index = generated.reshape(probs.shape).argmax(axis=-1)
return winning_index, self.pvals_flat[0][winning_index]
@application
def cost(self, readouts, outputs):
# WARNING: unfortunately this application method works
# just fine when `readouts` and `outputs` have
# different dimensions. Be careful!
return self.softmax.categorical_cross_entropy(
outputs, readouts, extra_ndim=readouts.ndim - 2)
@application
def initial_outputs(self, batch_size):
return self.initial_output * tensor.ones((batch_size, ), dtype='int64')
def get_dim(self, name):
if name == 'outputs':
return 0
return super(SoftmaxEmitter, self).get_dim(name)
def softmax_layer(h, y, vocab_size, hidden_size):
hidden_to_output = Linear(name='hidden_to_output', input_dim=hidden_size,
output_dim=vocab_size)
initialize([hidden_to_output])
linear_output = hidden_to_output.apply(h)
linear_output.name = 'linear_output'
softmax = NDimensionalSoftmax()
y_hat = softmax.apply(linear_output, extra_ndim=1)
y_hat.name = 'y_hat'
cost = softmax.categorical_cross_entropy(
y, linear_output, extra_ndim=1).mean()
cost.name = 'cost'
return y_hat, cost
def softmax_layer(h, y, vocab_size, hidden_size):
hidden_to_output = Linear(name='hidden_to_output',
input_dim=hidden_size,
output_dim=vocab_size)
initialize([hidden_to_output])
linear_output = hidden_to_output.apply(h)
linear_output.name = 'linear_output'
softmax = NDimensionalSoftmax()
y_hat = softmax.apply(linear_output, extra_ndim=1)
y_hat.name = 'y_hat'
cost = softmax.categorical_cross_entropy(y, linear_output,
extra_ndim=1).mean()
cost.name = 'cost'
return y_hat, cost
class SoftmaxEmitter(AbstractEmitter, Initializable, Random):
"""A softmax emitter for the case of integer outputs.
Interprets readout elements as energies corresponding to their indices.
Parameters
----------
initial_output : int or a scalar :class:`~theano.Variable`
The initial output.
"""
def __init__(self, initial_output=0, **kwargs):
super(SoftmaxEmitter, self).__init__(**kwargs)
self.initial_output = initial_output
self.softmax = NDimensionalSoftmax()
self.children = [self.softmax]
@application
def probs(self, readouts):
return self.softmax.apply(readouts, extra_ndim=readouts.ndim - 2)
@application
def emit(self, readouts):
probs = self.probs(readouts)
batch_size = probs.shape[0]
pvals_flat = probs.reshape((batch_size, -1))
generated = self.theano_rng.multinomial(pvals=pvals_flat)
return generated.reshape(probs.shape).argmax(axis=-1)
@application
def cost(self, readouts, outputs):
# WARNING: unfortunately this application method works
# just fine when `readouts` and `outputs` have
# different dimensions. Be careful!
return self.softmax.categorical_cross_entropy(
outputs, readouts, extra_ndim=readouts.ndim - 2)
@application
def costs(self, readouts):
return -self.softmax.log_probabilities(
readouts, extra_ndim=readouts.ndim - 2)
@application
def initial_outputs(self, batch_size):
return self.initial_output * tensor.ones((batch_size,), dtype='int64')
def get_dim(self, name):
if name == 'outputs':
return 0
return super(SoftmaxEmitter, self).get_dim(name)
def create_rnn(hidden_dim, vocab_dim, mode="rnn"):
# input
x = tensor.imatrix('inchar')
y = tensor.imatrix('outchar')
#
W = LookupTable(
name="W1",
#dim = hidden_dim*4,
dim=hidden_dim,
length=vocab_dim,
weights_init=initialization.IsotropicGaussian(0.01),
biases_init=initialization.Constant(0))
if mode == "lstm":
# Long Short Term Memory
H = LSTM(hidden_dim,
name='H',
weights_init=initialization.IsotropicGaussian(0.01),
biases_init=initialization.Constant(0.0))
else:
# recurrent history weight
H = SimpleRecurrent(
name="H",
dim=hidden_dim,
activation=Tanh(),
weights_init=initialization.IsotropicGaussian(0.01))
#
S = Linear(name="W2",
input_dim=hidden_dim,
output_dim=vocab_dim,
weights_init=initialization.IsotropicGaussian(0.01),
biases_init=initialization.Constant(0))
A = NDimensionalSoftmax(name="softmax")
initLayers([W, H, S])
activations = W.apply(x)
hiddens = H.apply(activations) #[0]
activations2 = S.apply(hiddens)
y_hat = A.apply(activations2, extra_ndim=1)
cost = A.categorical_cross_entropy(y, activations2, extra_ndim=1).mean()
cg = ComputationGraph(cost)
#print VariableFilter(roles=[WEIGHT])(cg.variables)
#W1,H,W2 = VariableFilter(roles=[WEIGHT])(cg.variables)
layers = (x, W, H, S, A, y)
return cg, layers, y_hat, cost
def rating_cost(pred_score,
true_ratings,
input_masks,
output_masks,
D,
d,
std=1.0,
alpha=0.01):
pred_score_cum = T.extra_ops.cumsum(pred_score, axis=2)
prob_item_ratings = NDimensionalSoftmax(name='rating_cost_sf').apply(
pred_score_cum, extra_ndim=1)
accu_prob_1N = T.extra_ops.cumsum(prob_item_ratings, axis=2)
accu_prob_N1 = T.extra_ops.cumsum(prob_item_ratings[:, :, ::-1],
axis=2)[:, :, ::-1]
mask1N = T.extra_ops.cumsum(true_ratings[:, :, ::-1], axis=2)[:, :, ::-1]
maskN1 = T.extra_ops.cumsum(true_ratings, axis=2)
cost_ordinal_1N = -T.sum(
(T.log(prob_item_ratings) - T.log(accu_prob_1N)) * mask1N, axis=2)
cost_ordinal_N1 = -T.sum(
(T.log(prob_item_ratings) - T.log(accu_prob_N1)) * maskN1, axis=2)
cost_ordinal = cost_ordinal_1N + cost_ordinal_N1
nll_item_ratings = -(true_ratings * T.log(prob_item_ratings)).sum(axis=2)
nll = std * nll_item_ratings.sum(
axis=1) * 1.0 * D / (D - d + 1e-6) + alpha * cost_ordinal.sum(
axis=1) * 1.0 * D / (D - d + 1e-6)
cost = T.mean(nll)
return cost, nll, nll_item_ratings, cost_ordinal_1N, cost_ordinal_N1, prob_item_ratings
def __init__(self,
lm_costs_name,
lm_weight,
normalize_am_weights=False,
normalize_lm_weights=False,
normalize_tot_weights=True,
am_beta=1.0,
**kwargs):
super(ShallowFusionReadout, self).__init__(**kwargs)
self.lm_costs_name = lm_costs_name
self.lm_weight = lm_weight
self.normalize_am_weights = normalize_am_weights
self.normalize_lm_weights = normalize_lm_weights
self.normalize_tot_weights = normalize_tot_weights
self.am_beta = am_beta
self.softmax = NDimensionalSoftmax()
self.children += [self.softmax]
def __init__(self, input1_size, input2_size, lookup1_dim=200, lookup2_dim=200, hidden_size=512):
self.hidden_size = hidden_size
self.input1_size = input1_size
self.input2_size = input2_size
self.lookup1_dim = lookup1_dim
self.lookup2_dim = lookup2_dim
x1 = tensor.lmatrix('durations')
x2 = tensor.lmatrix('syllables')
y = tensor.lmatrix('pitches')
lookup1 = LookupTable(dim=self.lookup1_dim, length=self.input1_size, name='lookup1',
weights_init=initialization.Uniform(width=0.01),
biases_init=Constant(0))
lookup1.initialize()
lookup2 = LookupTable(dim=self.lookup2_dim, length=self.input2_size, name='lookup2',
weights_init=initialization.Uniform(width=0.01),
biases_init=Constant(0))
lookup2.initialize()
merge = Merge(['lookup1', 'lookup2'], [self.lookup1_dim, self.lookup2_dim], self.hidden_size,
weights_init=initialization.Uniform(width=0.01),
biases_init=Constant(0))
merge.initialize()
recurrent_block = LSTM(dim=self.hidden_size, activation=Tanh(),
weights_init=initialization.Uniform(width=0.01)) #RecurrentStack([LSTM(dim=self.hidden_size, activation=Tanh())] * 3)
recurrent_block.initialize()
linear = Linear(input_dim=self.hidden_size, output_dim=self.input1_size,
weights_init=initialization.Uniform(width=0.01),
biases_init=Constant(0))
linear.initialize()
softmax = NDimensionalSoftmax()
l1 = lookup1.apply(x1)
l2 = lookup2.apply(x2)
m = merge.apply(l1, l2)
h = recurrent_block.apply(m)
a = linear.apply(h)
y_hat = softmax.apply(a, extra_ndim=1)
# ValueError: x must be 1-d or 2-d tensor of floats. Got TensorType(float64, 3D)
self.Cost = softmax.categorical_cross_entropy(y, a, extra_ndim=1).mean()
self.ComputationGraph = ComputationGraph(self.Cost)
self.Model = Model(y_hat)
def softmax_output_layer(x, h, y, in_size, out_size, hidden_size, pred):
if connect_h_to_o:
hidden_to_output = Linear(name='hidden_to_output' + str(pred),
input_dim=hidden_size * len(h),
output_dim=out_size)
hiddens = T.concatenate([hidden for hidden in h], axis=2)
else:
hidden_to_output = Linear(name='hidden_to_output' + str(pred),
input_dim=hidden_size,
output_dim=out_size)
hiddens = h[-1]
initialize([hidden_to_output])
linear_output = hidden_to_output.apply(hiddens)
linear_output.name = 'linear_output'
softmax = NDimensionalSoftmax()
extra_ndim = 1 if single_dim_out else 2
y_hat = softmax.apply(linear_output, extra_ndim=extra_ndim)
cost = softmax.categorical_cross_entropy(y,
linear_output,
extra_ndim=extra_ndim).mean()
return y_hat, cost
def softmax_layer(self, h, y):
"""
Perform Softmax over the hidden state in order to
predict the next word in the sequence and compute
the loss.
:param h The hidden state sequence
:param y The target words
"""
hidden_to_output = Linear(name='hidden_to_output', input_dim=self.hidden_size,
output_dim=self.vocab_size)
initialize(hidden_to_output, sqrt(6.0 / (self.hidden_size + self.vocab_size)))
linear_output = hidden_to_output.apply(h)
linear_output.name = 'linear_output'
softmax = NDimensionalSoftmax(name="lm_softmax")
y_hat = softmax.log_probabilities(linear_output, extra_ndim=1)
y_hat.name = 'y_hat'
cost = softmax.categorical_cross_entropy(y, linear_output, extra_ndim=1).mean()
cost.name = 'cost'
return y_hat, cost
def __init__(self, mlp, dim, k, const=1e-5, **kwargs):
super(GMMMLP, self).__init__(**kwargs)
self.dim = dim
self.const = const
self.k = k
input_dim = mlp.output_dim
self.mu = MLP(activations=[Identity()],
dims=[input_dim, dim],
name=self.name + "_mu")
self.sigma = MLP(activations=[SoftPlus()],
dims=[input_dim, dim],
name=self.name + "_sigma")
self.coeff = MLP(activations=[Identity()],
dims=[input_dim, k],
name=self.name + "_coeff")
self.coeff2 = NDimensionalSoftmax()
self.mlp = mlp
self.children = [
self.mlp, self.mu, self.sigma, self.coeff, self.coeff2
]
def __init__(self, lm_costs_name, lm_weight,
normalize_am_weights=False,
normalize_lm_weights=False,
normalize_tot_weights=True,
am_beta=1.0,
**kwargs):
super(ShallowFusionReadout, self).__init__(**kwargs)
self.lm_costs_name = lm_costs_name
self.lm_weight = lm_weight
self.normalize_am_weights = normalize_am_weights
self.normalize_lm_weights = normalize_lm_weights
self.normalize_tot_weights = normalize_tot_weights
self.am_beta = am_beta
self.softmax = NDimensionalSoftmax()
self.children += [self.softmax]
class GMMMLP(Initializable):
"""An mlp brick that branchs out to output
sigma and mu for GMM
Parameters
----------
mlp: MLP brick
the main mlp to wrap around.
dim:
output dim
"""
def __init__(self, mlp, dim, k, const=1e-5, **kwargs):
super(GMMMLP, self).__init__(**kwargs)
self.dim = dim
self.const = const
self.k = k
input_dim = mlp.output_dim
self.mu = MLP(activations=[Identity()],
dims=[input_dim, dim],
name=self.name + "_mu")
self.sigma = MLP(activations=[SoftPlus()],
dims=[input_dim, dim],
name=self.name + "_sigma")
self.coeff = MLP(activations=[Identity()],
dims=[input_dim, k],
name=self.name + "_coeff")
self.coeff2 = NDimensionalSoftmax()
self.mlp = mlp
self.children = [self.mlp, self.mu,
self.sigma, self.coeff, self.coeff2]
#self.children.extend(self.mlp.children)
@application
def apply(self, inputs):
state = self.mlp.apply(inputs)
mu = self.mu.apply(state)
sigma = self.sigma.apply(state)
coeff = self.coeff2.apply(self.coeff.apply(state),
extra_ndim=state.ndim - 2) + self.const
return mu, sigma, coeff
@property
def output_dim(self):
return self.dim
class GMMMLP(Initializable):
"""An mlp brick that branchs out to output
sigma and mu for GMM
Parameters
----------
mlp: MLP brick
the main mlp to wrap around.
dim:
output dim
"""
def __init__(self, mlp, dim, k, const=1e-5, **kwargs):
super(GMMMLP, self).__init__(**kwargs)
self.dim = dim
self.const = const
self.k = k
input_dim = mlp.output_dim
self.mu = MLP(activations=[Identity()],
dims=[input_dim, dim],
name=self.name + "_mu")
self.sigma = MLP(activations=[SoftPlus()],
dims=[input_dim, dim],
name=self.name + "_sigma")
self.coeff = MLP(activations=[Identity()],
dims=[input_dim, k],
name=self.name + "_coeff")
self.coeff2 = NDimensionalSoftmax()
self.mlp = mlp
self.children = [
self.mlp, self.mu, self.sigma, self.coeff, self.coeff2
]
#self.children.extend(self.mlp.children)
@application
def apply(self, inputs):
state = self.mlp.apply(inputs)
mu = self.mu.apply(state)
sigma = self.sigma.apply(state)
coeff = self.coeff2.apply(self.coeff.apply(state),
extra_ndim=state.ndim - 2) + self.const
return mu, sigma, coeff
@property
def output_dim(self):
return self.dim
def __init__(self, mlp, dim, k, const=1e-5, **kwargs):
super(GMMMLP, self).__init__(**kwargs)
self.dim = dim
self.const = const
self.k = k
input_dim = mlp.output_dim
self.mu = MLP(activations=[Identity()],
dims=[input_dim, dim],
name=self.name + "_mu")
self.sigma = MLP(activations=[SoftPlus()],
dims=[input_dim, dim],
name=self.name + "_sigma")
self.coeff = MLP(activations=[Identity()],
dims=[input_dim, k],
name=self.name + "_coeff")
self.coeff2 = NDimensionalSoftmax()
self.mlp = mlp
self.children = [self.mlp, self.mu,
self.sigma, self.coeff, self.coeff2]
def __init__(self, visual_dim, textual_dim, output_dim, hidden_size,
init_ranges, **kwargs):
(visual_range, textual_range, linear_range_1, linear_range_2,
linear_range_3) = init_ranges
manager_dim = visual_dim + textual_dim
visual_mlp = MLPGenreClassifier(
visual_dim,
output_dim,
hidden_size, [linear_range_1, linear_range_2, linear_range_3],
name='visual_mlp')
textual_mlp = MLPGenreClassifier(
textual_dim,
output_dim,
hidden_size, [linear_range_1, linear_range_2, linear_range_3],
name='textual_mlp')
# manager_mlp = MLPGenreClassifier(manager_dim, 2, hidden_size, [
# linear_range_1, linear_range_2, linear_range_3], output_act=Softmax,
# name='manager_mlp')
bn = BatchNormalization(input_dim=manager_dim, name='bn3')
manager_mlp = Sequence([
Linear(manager_dim,
2,
name='linear_output',
use_bias=False,
weights_init=initialization.Uniform(
width=linear_range_1)).apply,
],
name='manager_mlp')
fork = Fork(
input_dim=manager_dim,
output_dims=[2] * output_dim,
prototype=manager_mlp,
output_names=['linear_' + str(i) for i in range(output_dim)])
children = [visual_mlp, textual_mlp, fork, bn, NDimensionalSoftmax()]
kwargs.setdefault('use_bias', False)
kwargs.setdefault('children', children)
super(MoEClassifier, self).__init__(**kwargs)
def __init__(self, config_dict, init_type="xavier", **kwargs):
super(CharRNNModel, self).__init__(**kwargs)
self.batch_size = config_dict["batch_size"]
self.num_subwords = config_dict["num_subwords"]
self.num_words = config_dict["num_words"]
self.subword_embedding_size = config_dict["subword_embedding_size"]
self.input_vocab_size = config_dict["input_vocab_size"]
self.output_vocab_size = config_dict["output_vocab_size"]
self.subword_RNN_hidden_state_size = config_dict["subword_RNN_hidden_state_size"]
self.table_width = config_dict["table_width"]
self.max_out_dim = config_dict["max_out_dim"]
self.max_out_K = config_dict["max_out_K"]
self.lookup = LookupTable(length=self.input_vocab_size, dim=self.subword_embedding_size, name="input_lookup")
self.lookup.weights_init = Uniform(width=self.table_width)
self.lookup.biases_init = Constant(0)
if init_type == "xavier":
linear_init = XavierInitializationOriginal(self.subword_embedding_size, self.subword_RNN_hidden_state_size)
lstm_init = XavierInitializationOriginal(self.subword_embedding_size, self.subword_RNN_hidden_state_size)
else: # default is gaussian
linear_init = IsotropicGaussian()
lstm_init = IsotropicGaussian()
# The `inputs` are then split in this order: Input gates, forget gates, cells and output gates
self.linear_forward = Linear(
input_dim=self.subword_embedding_size,
output_dim=self.subword_RNN_hidden_state_size * 4,
name="linear_forward",
weights_init=linear_init,
biases_init=Constant(0.0),
)
self.language_model = LSTM(
dim=self.subword_RNN_hidden_state_size,
activation=Tanh(),
name="language_model_RNN",
weights_init=lstm_init,
biases_init=Constant(0.0),
)
self.max_out = LinearMaxout(
self.subword_RNN_hidden_state_size,
self.max_out_dim,
self.max_out_K,
name="max_out",
weights_init=IsotropicGaussian(),
biases_init=Constant(0.0),
)
self.softmax_linear = Linear(
self.max_out_dim,
self.output_vocab_size,
name="soft_max_linear",
weights_init=IsotropicGaussian(),
biases_init=Constant(0.0),
)
self.softmax = NDimensionalSoftmax()
self.children = [
self.lookup,
self.linear_forward,
self.language_model,
self.max_out,
self.softmax_linear,
self.softmax,
]
class LanguageModel(Initializable):
"""The dictionary-equipped language model.
Parameters
----------
emb_dim: int
The dimension of word embeddings (including for def model if standalone)
dim : int
The dimension of the RNNs states (including for def model if standalone)
num_input_words : int
The size of the LM's input vocabulary.
num_output_words : int
The size of the LM's output vocabulary.
vocab
The vocabulary object.
retrieval
The dictionary retrieval algorithm. If `None`, the language model
does not use any dictionary.
def_reader: either 'LSTM' or 'mean'
standalone_def_rnn : bool
If `True`, a standalone RNN with separate word embeddings is used
to embed definition. If `False` the language model is reused.
disregard_word_embeddings : bool
If `True`, the word embeddings are not used, only the information
from the definitions is used.
compose_type : str
If 'sum', the definition and word embeddings are averaged
If 'fully_connected_linear', a learned perceptron compose the 2
embeddings linearly
If 'fully_connected_relu', ...
If 'fully_connected_tanh', ...
"""
def __init__(self,
emb_dim,
emb_def_dim,
dim,
num_input_words,
def_num_input_words,
num_output_words,
vocab,
retrieval=None,
def_reader='LSTM',
standalone_def_lookup=True,
standalone_def_rnn=True,
disregard_word_embeddings=False,
compose_type='sum',
very_rare_threshold=[10],
cache_size=0,
**kwargs):
# TODO(tombosc): document
if emb_dim == 0:
emb_dim = dim
if emb_def_dim == 0:
emb_def_dim = emb_dim
if num_input_words == 0:
num_input_words = vocab.size()
if def_num_input_words == 0:
def_num_input_words = num_input_words
if (num_input_words !=
def_num_input_words) and (not standalone_def_lookup):
raise NotImplementedError()
self._very_rare_threshold = very_rare_threshold
self._num_input_words = num_input_words
self._num_output_words = num_output_words
self._vocab = vocab
self._retrieval = retrieval
self._disregard_word_embeddings = disregard_word_embeddings
self._compose_type = compose_type
self._word_to_id = WordToIdOp(self._vocab)
self._word_to_count = WordToCountOp(self._vocab)
children = []
self._cache = None
if cache_size > 0:
#TODO(tombosc) do we implement cache as LookupTable or theano matrix?
#self._cache = theano.shared(np.zeros((def_num_input_words, emb_dim)))
self._cache = LookupTable(cache_size,
emb_dim,
name='cache_def_embeddings')
children.append(self._cache)
if self._retrieval:
self._retrieve = RetrievalOp(retrieval)
self._main_lookup = LookupTable(self._num_input_words,
emb_dim,
name='main_lookup')
self._main_fork = Linear(emb_dim, 4 * dim, name='main_fork')
self._main_rnn = DebugLSTM(
dim, name='main_rnn') # TODO(tombosc): use regular LSTM?
children.extend([self._main_lookup, self._main_fork, self._main_rnn])
if self._retrieval:
if standalone_def_lookup:
lookup = None
else:
if emb_dim != emb_def_dim:
raise ValueError(
"emb_dim != emb_def_dim: cannot share lookup")
lookup = self._main_lookup
if def_reader == 'LSTM':
if standalone_def_rnn:
fork_and_rnn = None
else:
fork_and_rnn = (self._main_fork, self._main_rnn)
self._def_reader = LSTMReadDefinitions(def_num_input_words,
emb_def_dim,
dim,
vocab,
lookup,
fork_and_rnn,
cache=self._cache)
elif def_reader == 'mean':
self._def_reader = MeanPoolReadDefinitions(
def_num_input_words,
emb_def_dim,
dim,
vocab,
lookup,
translate=(emb_def_dim != dim),
normalize=False)
else:
raise Exception("def reader not understood")
self._combiner = MeanPoolCombiner(dim=dim,
emb_dim=emb_dim,
compose_type=compose_type)
children.extend([self._def_reader, self._combiner])
self._pre_softmax = Linear(dim, self._num_output_words)
self._softmax = NDimensionalSoftmax()
children.extend([self._pre_softmax, self._softmax])
super(LanguageModel, self).__init__(children=children, **kwargs)
def _push_initialization_config(self):
super(LanguageModel, self)._push_initialization_config()
if self._cache:
self._cache.weights_init = Constant(0.)
def set_def_embeddings(self, embeddings):
self._def_reader._def_lookup.parameters[0].set_value(
embeddings.astype(theano.config.floatX))
def get_def_embeddings_params(self):
return self._def_reader._def_lookup.parameters[0]
def get_cache_params(self):
return self._cache.W
def add_perplexity_measure(self, application_call, minus_logs, mask, name):
costs = (minus_logs * mask).sum(axis=0)
perplexity = tensor.exp(costs.sum() / mask.sum())
perplexity.tag.aggregation_scheme = Perplexity(costs.sum(), mask.sum())
full_name = "perplexity_" + name
application_call.add_auxiliary_variable(perplexity, name=full_name)
return costs
@application
def apply(self, application_call, words, mask):
"""Compute the log-likelihood for a batch of sequences.
words
An integer matrix of shape (B, T), where T is the number of time
step, B is the batch size. Note that this order of the axis is
different from what all RNN bricks consume, hence and the axis
should be transposed at some point.
mask
A float32 matrix of shape (B, T). Zeros indicate the padding.
"""
if self._retrieval:
defs, def_mask, def_map = self._retrieve(words)
def_embeddings = self._def_reader.apply(defs, def_mask)
# Auxililary variable for debugging
application_call.add_auxiliary_variable(def_embeddings.shape[0],
name="num_definitions")
word_ids = self._word_to_id(words)
# shortlisting
input_word_ids = (
tensor.lt(word_ids, self._num_input_words) * word_ids +
tensor.ge(word_ids, self._num_input_words) * self._vocab.unk)
output_word_ids = (
tensor.lt(word_ids, self._num_output_words) * word_ids +
tensor.ge(word_ids, self._num_output_words) * self._vocab.unk)
application_call.add_auxiliary_variable(unk_ratio(
input_word_ids, mask, self._vocab.unk),
name='unk_ratio')
# Run the main rnn with combined inputs
word_embs = self._main_lookup.apply(input_word_ids)
application_call.add_auxiliary_variable(masked_root_mean_square(
word_embs, mask),
name='word_emb_RMS')
if self._retrieval:
rnn_inputs, updated, positions = self._combiner.apply(
word_embs, mask, def_embeddings, def_map)
else:
rnn_inputs = word_embs
updates = []
if self._cache:
flat_word_ids = word_ids.flatten()
flat_word_ids_to_update = flat_word_ids[positions]
# computing updates for cache
updates = [
(self._cache.W,
tensor.set_subtensor(self._cache.W[flat_word_ids_to_update],
updated))
]
application_call.add_auxiliary_variable(masked_root_mean_square(
word_embs, mask),
name='main_rnn_in_RMS')
main_rnn_states = self._main_rnn.apply(tensor.transpose(
self._main_fork.apply(rnn_inputs), (1, 0, 2)),
mask=mask.T)[0]
# The first token is not predicted
logits = self._pre_softmax.apply(main_rnn_states[:-1])
targets = output_word_ids.T[1:]
out_softmax = self._softmax.apply(logits, extra_ndim=1)
application_call.add_auxiliary_variable(out_softmax.copy(),
name="proba_out")
minus_logs = self._softmax.categorical_cross_entropy(targets,
logits,
extra_ndim=1)
targets_mask = mask.T[1:]
costs = self.add_perplexity_measure(application_call, minus_logs,
targets_mask, "")
missing_embs = tensor.eq(input_word_ids,
self._vocab.unk).astype('int32') # (bs, L)
self.add_perplexity_measure(application_call, minus_logs,
targets_mask * missing_embs.T[:-1],
"after_mis_word_embs")
self.add_perplexity_measure(application_call, minus_logs,
targets_mask * (1 - missing_embs.T[:-1]),
"after_word_embs")
word_counts = self._word_to_count(words)
very_rare_masks = []
for threshold in self._very_rare_threshold:
very_rare_mask = tensor.lt(word_counts, threshold).astype('int32')
very_rare_mask = targets_mask * (very_rare_mask.T[:-1])
very_rare_masks.append(very_rare_mask)
self.add_perplexity_measure(application_call, minus_logs,
very_rare_mask,
"after_very_rare_" + str(threshold))
if self._retrieval:
has_def = tensor.zeros_like(output_word_ids)
has_def = tensor.inc_subtensor(
has_def[def_map[:, 0], def_map[:, 1]], 1)
mask_targets_has_def = has_def.T[:-1] * targets_mask # (L-1, bs)
self.add_perplexity_measure(application_call, minus_logs,
mask_targets_has_def, "after_def_embs")
for thresh, very_rare_mask in zip(self._very_rare_threshold,
very_rare_masks):
self.add_perplexity_measure(
application_call, minus_logs,
very_rare_mask * mask_targets_has_def,
"after_def_very_rare_" + str(thresh))
application_call.add_auxiliary_variable(mask_targets_has_def.T,
name='mask_def_emb')
return costs, updates
def __init__(self,
emb_dim,
emb_def_dim,
dim,
num_input_words,
def_num_input_words,
num_output_words,
vocab,
retrieval=None,
def_reader='LSTM',
standalone_def_lookup=True,
standalone_def_rnn=True,
disregard_word_embeddings=False,
compose_type='sum',
very_rare_threshold=[10],
cache_size=0,
**kwargs):
# TODO(tombosc): document
if emb_dim == 0:
emb_dim = dim
if emb_def_dim == 0:
emb_def_dim = emb_dim
if num_input_words == 0:
num_input_words = vocab.size()
if def_num_input_words == 0:
def_num_input_words = num_input_words
if (num_input_words !=
def_num_input_words) and (not standalone_def_lookup):
raise NotImplementedError()
self._very_rare_threshold = very_rare_threshold
self._num_input_words = num_input_words
self._num_output_words = num_output_words
self._vocab = vocab
self._retrieval = retrieval
self._disregard_word_embeddings = disregard_word_embeddings
self._compose_type = compose_type
self._word_to_id = WordToIdOp(self._vocab)
self._word_to_count = WordToCountOp(self._vocab)
children = []
self._cache = None
if cache_size > 0:
#TODO(tombosc) do we implement cache as LookupTable or theano matrix?
#self._cache = theano.shared(np.zeros((def_num_input_words, emb_dim)))
self._cache = LookupTable(cache_size,
emb_dim,
name='cache_def_embeddings')
children.append(self._cache)
if self._retrieval:
self._retrieve = RetrievalOp(retrieval)
self._main_lookup = LookupTable(self._num_input_words,
emb_dim,
name='main_lookup')
self._main_fork = Linear(emb_dim, 4 * dim, name='main_fork')
self._main_rnn = DebugLSTM(
dim, name='main_rnn') # TODO(tombosc): use regular LSTM?
children.extend([self._main_lookup, self._main_fork, self._main_rnn])
if self._retrieval:
if standalone_def_lookup:
lookup = None
else:
if emb_dim != emb_def_dim:
raise ValueError(
"emb_dim != emb_def_dim: cannot share lookup")
lookup = self._main_lookup
if def_reader == 'LSTM':
if standalone_def_rnn:
fork_and_rnn = None
else:
fork_and_rnn = (self._main_fork, self._main_rnn)
self._def_reader = LSTMReadDefinitions(def_num_input_words,
emb_def_dim,
dim,
vocab,
lookup,
fork_and_rnn,
cache=self._cache)
elif def_reader == 'mean':
self._def_reader = MeanPoolReadDefinitions(
def_num_input_words,
emb_def_dim,
dim,
vocab,
lookup,
translate=(emb_def_dim != dim),
normalize=False)
else:
raise Exception("def reader not understood")
self._combiner = MeanPoolCombiner(dim=dim,
emb_dim=emb_dim,
compose_type=compose_type)
children.extend([self._def_reader, self._combiner])
self._pre_softmax = Linear(dim, self._num_output_words)
self._softmax = NDimensionalSoftmax()
children.extend([self._pre_softmax, self._softmax])
super(LanguageModel, self).__init__(children=children, **kwargs)
class MinRiskInitialContextSequenceGenerator(InitialContextSequenceGenerator):
def __init__(self, *args, **kwargs):
self.softmax = NDimensionalSoftmax()
super(MinRiskInitialContextSequenceGenerator,
self).__init__(*args, **kwargs)
self.children.append(self.softmax)
@application
def probs(self, readouts):
return self.softmax.apply(readouts, extra_ndim=readouts.ndim - 2)
# TODO: check where 'target_samples_mask' is used -- do we need a mask for context features (probably not)
# Note: the @application decorator inspects the arguments, and transparently adds args ('application_call')
@application(inputs=[
'representation', 'source_sentence_mask', 'target_samples_mask',
'target_samples', 'scores'
],
outputs=['cost'])
def expected_cost(self,
application_call,
representation,
source_sentence_mask,
target_samples,
target_samples_mask,
scores,
smoothing_constant=0.005,
**kwargs):
"""
emulate the process in sequence_generator.cost_matrix, but compute log probabilities instead of costs
for each sample, we need its probability according to the model (these could actually be passed from the
sampling model, which could be more efficient)
"""
# Transpose everything (note we can use transpose here only if it's 2d, otherwise we need dimshuffle)
source_sentence_mask = source_sentence_mask.T
# make samples (time, batch)
samples = target_samples.T
samples_mask = target_samples_mask.T
# we need this to set the 'attended' kwarg
keywords = {
'mask': target_samples_mask,
'outputs': target_samples,
'attended': representation,
'attended_mask': source_sentence_mask
}
batch_size = samples.shape[1]
# Prepare input for the iterative part
states = dict_subset(keywords, self._state_names, must_have=False)
# masks in context are optional (e.g. `attended_mask`)
# contexts = dict_subset(keywords, self._context_names, must_have=False)
# add the initial state context features
contexts = dict_subset(keywords, self._context_names, must_have=False)
contexts['initial_state_context'] = kwargs['initial_state_context']
feedback = self.readout.feedback(samples)
inputs = self.fork.apply(feedback, as_dict=True)
# Run the recurrent network
results = self.transition.apply(mask=samples_mask,
return_initial_states=True,
as_dict=True,
**dict_union(inputs, states, contexts))
# Separate the deliverables. The last states are discarded: they
# are not used to predict any output symbol. The initial glimpses
# are discarded because they are not used for prediction.
# Remember, glimpses are computed _before_ output stage, states are
# computed after.
states = {name: results[name][:-1] for name in self._state_names}
glimpses = {name: results[name][1:] for name in self._glimpse_names}
# Compute the cost
feedback = tensor.roll(feedback, 1, 0)
feedback = tensor.set_subtensor(
feedback[0],
self.readout.feedback(self.readout.initial_outputs(batch_size)))
readouts = self.readout.readout(feedback=feedback,
**dict_union(states, glimpses,
contexts))
word_probs = self.probs(readouts)
word_probs = tensor.log(word_probs)
# Note: converting the samples to one-hot wastes space, but it gets the job done
# TODO: this may be the op that sometimes causes out-of-memory
one_hot_samples = tensor.eye(word_probs.shape[-1])[samples]
one_hot_samples.astype('float32')
actual_probs = word_probs * one_hot_samples
# reshape to (batch, time, prob), then sum over the batch dimension
# to get sequence-level probability
actual_probs = actual_probs.dimshuffle(1, 0, 2)
# we are first summing over vocabulary (only one non-zero cell per row)
sequence_probs = actual_probs.sum(axis=2)
sequence_probs = sequence_probs * target_samples_mask
# now sum over time dimension
sequence_probs = sequence_probs.sum(axis=1)
# reshape and do exp() to get the true probs back
# sequence_probs = tensor.exp(sequence_probs.reshape(scores.shape))
sequence_probs = sequence_probs.reshape(scores.shape)
# Note that the smoothing constant can be set by user
sequence_distributions = (
tensor.exp(sequence_probs * smoothing_constant) /
tensor.exp(sequence_probs * smoothing_constant).sum(axis=1,
keepdims=True))
# the following lines are done explicitly for code clarity
# -- first get sequence expectation, then sum up the expectations for every
# seq in the minibatch
expected_scores = (sequence_distributions * scores).sum(axis=1)
expected_scores = expected_scores.sum(axis=0)
return expected_scores
def __init__(self, mlp, target_size, frame_size, k, frnn_hidden_size, frnn_step_size, const=1e-5, **kwargs):
super(FRNNEmitter, self).__init__(**kwargs)
self.mlp = mlp
self.target_size = target_size
self.frame_size = frame_size
self.k = k
self.frnn_hidden_size = frnn_hidden_size
self.const = const
self.input_dim = self.mlp.output_dim
self.frnn_step_size = frnn_step_size
# adding a step if the division is not exact.
self.number_of_steps = frame_size // frnn_step_size
self.last_steps = frame_size % frnn_step_size
if self.last_steps != 0:
self.number_of_steps += 1
self.mu = MLP(activations=[Identity()], dims=[frnn_hidden_size, k * frnn_step_size], name=self.name + "_mu")
self.sigma = MLP(
activations=[SoftPlus()], dims=[frnn_hidden_size, k * frnn_step_size], name=self.name + "_sigma"
)
self.coeff = MLP(activations=[Identity()], dims=[frnn_hidden_size, k], name=self.name + "_coeff")
self.coeff2 = NDimensionalSoftmax()
self.frnn_initial_state = Linear(
input_dim=self.input_dim, output_dim=frnn_hidden_size, name="frnn_initial_state"
)
# self.frnn_hidden = Linear(
# input_dim=frnn_hidden_size,
# output_dim=frnn_hidden_size,
# activation=Tanh(),
# name="frnn_hidden")
self.frnn_activation = Tanh(name="frnn_activation")
self.frnn_linear_transition_state = Linear(
input_dim=frnn_hidden_size, output_dim=frnn_hidden_size, name="frnn_linear_transition_state"
)
self.frnn_linear_transition_input = Linear(
input_dim=self.frnn_step_size, output_dim=frnn_hidden_size, name="frnn_linear_transition_input"
)
# self.frnn_linear_transition_output = Linear (
# input_dim = frnn_hidden_size,
# output_dim = self.rnn_hidden_dim,
# name="frnn_linear_transition_output")
self.children = [
self.mlp,
self.mu,
self.sigma,
self.coeff,
self.coeff2,
self.frnn_initial_state,
self.frnn_activation,
self.frnn_linear_transition_state,
self.frnn_linear_transition_input,
]
def __init__(self,
emb_dim,
dim,
num_input_words,
num_output_words,
vocab,
proximity_coef=0,
proximity_distance='l2',
encoder='lstm',
decoder='lstm',
shared_rnn=False,
translate_layer=None,
word_dropout=0.,
tied_in_out=False,
vocab_keys=None,
seed=0,
reconstruction_coef=1.,
provide_targets=False,
**kwargs):
"""
translate_layer: either a string containing the activation function to use
either a list containg the list of activations for a MLP
"""
if emb_dim == 0:
emb_dim = dim
if num_input_words == 0:
num_input_words = vocab.size()
if num_output_words == 0:
num_output_words = vocab.size()
self._word_dropout = word_dropout
self._tied_in_out = tied_in_out
if not encoder:
if proximity_coef:
raise ValueError("Err: meaningless penalty term (no encoder)")
if not vocab_keys:
raise ValueError("Err: specify a key vocabulary (no encoder)")
if tied_in_out and num_input_words != num_output_words:
raise ValueError("Can't tie in and out embeddings. Different "
"vocabulary size")
if shared_rnn and (encoder != 'lstm' or decoder != 'lstm'):
raise ValueError(
"can't share RNN because either encoder or decoder"
"is not an RNN")
if shared_rnn and decoder == 'lstm_c':
raise ValueError(
"can't share RNN because the decoder takes different"
"inputs")
if word_dropout < 0 or word_dropout > 1:
raise ValueError("invalid value for word dropout",
str(word_dropout))
if proximity_distance not in ['l1', 'l2', 'cos']:
raise ValueError(
"unrecognized distance: {}".format(proximity_distance))
if proximity_coef and emb_dim != dim and not translate_layer:
raise ValueError(
"""if proximity penalisation, emb_dim should equal dim or
there should be a translate layer""")
if encoder not in [
None, 'lstm', 'bilstm', 'mean', 'weighted_mean', 'max_bilstm',
'bilstm_sum', 'max_bilstm_sum'
]:
raise ValueError('encoder not recognized')
if decoder not in ['skip-gram', 'lstm', 'lstm_c']:
raise ValueError('decoder not recognized')
self._proximity_distance = proximity_distance
self._decoder = decoder
self._encoder = encoder
self._num_input_words = num_input_words
self._num_output_words = num_output_words
self._vocab = vocab
self._proximity_coef = proximity_coef
self._reconstruction_coef = reconstruction_coef
self._provide_targets = provide_targets
self._word_to_id = WordToIdOp(self._vocab)
if vocab_keys:
self._key_to_id = WordToIdOp(vocab_keys)
children = []
if encoder or (not encoder and decoder in ['lstm', 'lstm_c']):
self._main_lookup = LookupTable(self._num_input_words,
emb_dim,
name='main_lookup')
children.append(self._main_lookup)
if provide_targets:
# this is useful to simulate Hill's baseline without pretrained embeddings
# in the encoder, only as targets for the encoder.
self._target_lookup = LookupTable(self._num_input_words,
emb_dim,
name='target_lookup')
children.append(self._target_lookup)
if not encoder:
self._key_lookup = LookupTable(vocab_keys.size(),
emb_dim,
name='key_lookup')
children.append(self._key_lookup)
elif encoder == 'lstm':
self._encoder_fork = Linear(emb_dim, 4 * dim, name='encoder_fork')
self._encoder_rnn = LSTM(dim, name='encoder_rnn')
children.extend([self._encoder_fork, self._encoder_rnn])
elif encoder in ['bilstm', 'max_bilstm']:
# dim is the dim of the concatenated vector
self._encoder_fork = Linear(emb_dim, 2 * dim, name='encoder_fork')
self._encoder_rnn = Bidirectional(LSTM(dim / 2,
name='encoder_rnn'))
children.extend([self._encoder_fork, self._encoder_rnn])
elif encoder in ['bilstm_sum', 'max_bilstm_sum']:
self._encoder_fork = Linear(emb_dim, 4 * dim, name='encoder_fork')
self._encoder_rnn = BidirectionalSum(LSTM(dim, name='encoder_rnn'))
children.extend([self._encoder_fork, self._encoder_rnn])
elif encoder == 'mean':
pass
elif encoder == 'weighted_mean':
self._encoder_w = MLP([Logistic()], [dim, 1],
name="encoder_weights")
children.extend([self._encoder_w])
else:
raise NotImplementedError()
if decoder in ['lstm', 'lstm_c']:
dim_after_translate = emb_dim
if shared_rnn:
self._decoder_fork = self._encoder_fork
self._decoder_rnn = self._encoder_rnn
else:
if decoder == 'lstm_c':
dim_2 = dim + emb_dim
else:
dim_2 = dim
self._decoder_fork = Linear(dim_2,
4 * dim,
name='decoder_fork')
self._decoder_rnn = LSTM(dim, name='decoder_rnn')
children.extend([self._decoder_fork, self._decoder_rnn])
elif decoder == 'skip-gram':
dim_after_translate = emb_dim
self._translate_layer = None
activations = {'sigmoid': Logistic(), 'tanh': Tanh(), 'linear': None}
if translate_layer:
if type(translate_layer) == str:
translate_layer = [translate_layer]
assert (type(translate_layer) == list)
activations_translate = [activations[a] for a in translate_layer]
dims_translate = [
dim,
] * len(translate_layer) + [dim_after_translate]
self._translate_layer = MLP(activations_translate,
dims_translate,
name="translate_layer")
children.append(self._translate_layer)
if not self._tied_in_out:
self._pre_softmax = Linear(emb_dim, self._num_output_words)
children.append(self._pre_softmax)
if decoder in ['lstm', 'lstm_c']:
self._softmax = NDimensionalSoftmax()
elif decoder in ['skip-gram']:
self._softmax = Softmax()
children.append(self._softmax)
super(Seq2Seq, self).__init__(children=children, **kwargs)
class ExtractiveQAModel(Initializable):
"""The dictionary-equipped extractive QA model.
Parameters
----------
dim : int
The default dimensionality for the components.
emd_dim : int
The dimensionality for the embeddings. If 0, `dim` is used.
coattention : bool
Use the coattention mechanism.
num_input_words : int
The number of input words. If 0, `vocab.size()` is used.
The vocabulary object.
use_definitions : bool
Triggers the use of definitions.
reuse_word_embeddings : bool
compose_type : str
"""
def __init__(self, dim, emb_dim, readout_dims, num_input_words,
def_num_input_words, vocab, use_definitions, def_word_gating,
compose_type, coattention, def_reader, reuse_word_embeddings,
random_unk, **kwargs):
self._vocab = vocab
if emb_dim == 0:
emb_dim = dim
if num_input_words == 0:
num_input_words = vocab.size()
if def_num_input_words == 0:
def_num_input_words = num_input_words
self._coattention = coattention
self._num_input_words = num_input_words
self._use_definitions = use_definitions
self._random_unk = random_unk
self._reuse_word_embeddings = reuse_word_embeddings
lookup_num_words = num_input_words
if reuse_word_embeddings:
lookup_num_words = max(num_input_words, def_num_input_words)
if random_unk:
lookup_num_words = vocab.size()
# Dima: we can have slightly less copy-paste here if we
# copy the RecurrentFromFork class from my other projects.
children = []
self._lookup = LookupTable(lookup_num_words, emb_dim)
self._encoder_fork = Linear(emb_dim, 4 * dim, name='encoder_fork')
self._encoder_rnn = LSTM(dim, name='encoder_rnn')
self._question_transform = Linear(dim, dim, name='question_transform')
self._bidir_fork = Linear(3 * dim if coattention else 2 * dim,
4 * dim,
name='bidir_fork')
self._bidir = Bidirectional(LSTM(dim), name='bidir')
children.extend([
self._lookup, self._encoder_fork, self._encoder_rnn,
self._question_transform, self._bidir, self._bidir_fork
])
activations = [Rectifier()] * len(readout_dims) + [None]
readout_dims = [2 * dim] + readout_dims + [1]
self._begin_readout = MLP(activations,
readout_dims,
name='begin_readout')
self._end_readout = MLP(activations, readout_dims, name='end_readout')
self._softmax = NDimensionalSoftmax()
children.extend(
[self._begin_readout, self._end_readout, self._softmax])
if self._use_definitions:
# A potential bug here: we pass the same vocab to the def reader.
# If a different token is reserved for UNK in text and in the definitions,
# we can be screwed.
def_reader_class = eval(def_reader)
def_reader_kwargs = dict(
num_input_words=def_num_input_words,
dim=dim,
emb_dim=emb_dim,
vocab=vocab,
lookup=self._lookup if reuse_word_embeddings else None)
if def_reader_class == MeanPoolReadDefinitions:
def_reader_kwargs.update(dict(normalize=True, translate=False))
self._def_reader = def_reader_class(**def_reader_kwargs)
self._combiner = MeanPoolCombiner(dim=dim,
emb_dim=emb_dim,
def_word_gating=def_word_gating,
compose_type=compose_type)
children.extend([self._def_reader, self._combiner])
super(ExtractiveQAModel, self).__init__(children=children, **kwargs)
# create default input variables
self.contexts = tensor.lmatrix('contexts')
self.context_mask = tensor.matrix('contexts_mask')
self.questions = tensor.lmatrix('questions')
self.question_mask = tensor.matrix('questions_mask')
self.answer_begins = tensor.lvector('answer_begins')
self.answer_ends = tensor.lvector('answer_ends')
input_vars = [
self.contexts, self.context_mask, self.questions,
self.question_mask, self.answer_begins, self.answer_ends
]
if self._use_definitions:
self.defs = tensor.lmatrix('defs')
self.def_mask = tensor.matrix('def_mask')
self.contexts_def_map = tensor.lmatrix('contexts_def_map')
self.questions_def_map = tensor.lmatrix('questions_def_map')
input_vars.extend([
self.defs, self.def_mask, self.contexts_def_map,
self.questions_def_map
])
self.input_vars = OrderedDict([(var.name, var) for var in input_vars])
def set_embeddings(self, embeddings):
self._lookup.parameters[0].set_value(
embeddings.astype(theano.config.floatX))
def embeddings_var(self):
return self._lookup.parameters[0]
def def_reading_parameters(self):
parameters = Selector(self._def_reader).get_parameters().values()
parameters.extend(Selector(self._combiner).get_parameters().values())
if self._reuse_word_embeddings:
lookup_parameters = Selector(
self._lookup).get_parameters().values()
parameters = [p for p in parameters if p not in lookup_parameters]
return parameters
@application
def _encode(self,
application_call,
text,
mask,
def_embs=None,
def_map=None,
text_name=None):
if not self._random_unk:
text = (tensor.lt(text, self._num_input_words) * text +
tensor.ge(text, self._num_input_words) * self._vocab.unk)
if text_name:
application_call.add_auxiliary_variable(
unk_ratio(text, mask, self._vocab.unk),
name='{}_unk_ratio'.format(text_name))
embs = self._lookup.apply(text)
if self._random_unk:
embs = (tensor.lt(text, self._num_input_words)[:, :, None] * embs +
tensor.ge(text, self._num_input_words)[:, :, None] *
disconnected_grad(embs))
if def_embs:
embs = self._combiner.apply(embs, mask, def_embs, def_map)
add_role(embs, EMBEDDINGS)
encoded = flip01(
self._encoder_rnn.apply(self._encoder_fork.apply(flip01(embs)),
mask=mask.T)[0])
return encoded
@application
def apply(self,
application_call,
contexts,
contexts_mask,
questions,
questions_mask,
answer_begins,
answer_ends,
defs=None,
def_mask=None,
contexts_def_map=None,
questions_def_map=None):
def_embs = None
if self._use_definitions:
def_embs = self._def_reader.apply(defs, def_mask)
context_enc = self._encode(contexts, contexts_mask, def_embs,
contexts_def_map, 'context')
question_enc_pre = self._encode(questions, questions_mask, def_embs,
questions_def_map, 'question')
question_enc = tensor.tanh(
self._question_transform.apply(question_enc_pre))
# should be (batch size, context length, question_length)
affinity = tensor.batched_dot(context_enc, flip12(question_enc))
affinity_mask = contexts_mask[:, :, None] * questions_mask[:, None, :]
affinity = affinity * affinity_mask - 1000.0 * (1 - affinity_mask)
# soft-aligns every position in the context to positions in the question
d2q_att_weights = self._softmax.apply(affinity, extra_ndim=1)
application_call.add_auxiliary_variable(d2q_att_weights.copy(),
name='d2q_att_weights')
# soft-aligns every position in the question to positions in the document
q2d_att_weights = self._softmax.apply(flip12(affinity), extra_ndim=1)
application_call.add_auxiliary_variable(q2d_att_weights.copy(),
name='q2d_att_weights')
# question encoding "in the view of the document"
question_enc_informed = tensor.batched_dot(q2d_att_weights,
context_enc)
question_enc_concatenated = tensor.concatenate(
[question_enc, question_enc_informed], 2)
# document encoding "in the view of the question"
context_enc_informed = tensor.batched_dot(d2q_att_weights,
question_enc_concatenated)
if self._coattention:
context_enc_concatenated = tensor.concatenate(
[context_enc, context_enc_informed], 2)
else:
question_repr_repeated = tensor.repeat(question_enc[:, [-1], :],
context_enc.shape[1],
axis=1)
context_enc_concatenated = tensor.concatenate(
[context_enc, question_repr_repeated], 2)
# note: forward and backward LSTMs share the
# input weights in the current impl
bidir_states = flip01(
self._bidir.apply(self._bidir_fork.apply(
flip01(context_enc_concatenated)),
mask=contexts_mask.T)[0])
begin_readouts = self._begin_readout.apply(bidir_states)[:, :, 0]
begin_readouts = begin_readouts * contexts_mask - 1000.0 * (
1 - contexts_mask)
begin_costs = self._softmax.categorical_cross_entropy(
answer_begins, begin_readouts)
end_readouts = self._end_readout.apply(bidir_states)[:, :, 0]
end_readouts = end_readouts * contexts_mask - 1000.0 * (1 -
contexts_mask)
end_costs = self._softmax.categorical_cross_entropy(
answer_ends, end_readouts)
predicted_begins = begin_readouts.argmax(axis=-1)
predicted_ends = end_readouts.argmax(axis=-1)
exact_match = (tensor.eq(predicted_begins, answer_begins) *
tensor.eq(predicted_ends, answer_ends))
application_call.add_auxiliary_variable(predicted_begins,
name='predicted_begins')
application_call.add_auxiliary_variable(predicted_ends,
name='predicted_ends')
application_call.add_auxiliary_variable(exact_match,
name='exact_match')
return begin_costs + end_costs
def apply_with_default_vars(self):
return self.apply(*self.input_vars.values())
def __init__(self, input_sources_list, input_sources_vocab_size_list,
output_source, output_source_vocab_size,
lookup_dim=200, hidden_size=256, recurrent_stack_size=1):
self.InputSources = input_sources_list
self.InputSourcesVocab = input_sources_vocab_size_list
self.OutputSource = output_source
self.OutputSourceVocab = output_source_vocab_size
inputs = [tensor.lmatrix(source) for source in input_sources_list]
output = tensor.lmatrix(output_source)
lookups = self.get_lookups(lookup_dim, input_sources_vocab_size_list)
for lookup in lookups:
lookup.initialize()
merge = Merge([lookup.name for lookup in lookups], [lookup.dim for lookup in lookups], hidden_size,
weights_init=initialization.Uniform(width=0.01),
biases_init=Constant(0))
merge.initialize()
linear0 = Linear(input_dim=hidden_size, output_dim=hidden_size,
weights_init=initialization.Uniform(width=0.01),
biases_init=Constant(0), name='linear0')
linear0.initialize()
recurrent_blocks = []
for i in range(recurrent_stack_size):
recurrent_blocks.append(SimpleRecurrent(
dim=hidden_size, activation=Tanh(),
weights_init=initialization.Uniform(width=0.01),
use_bias=False))
for i, recurrent_block in enumerate(recurrent_blocks):
recurrent_block.name = 'recurrent'+str(i+1)
recurrent_block.initialize()
linear_out = Linear(input_dim=hidden_size, output_dim=output_source_vocab_size,
weights_init=initialization.Uniform(width=0.01),
biases_init=Constant(0), name='linear_out')
linear_out.initialize()
softmax = NDimensionalSoftmax(name='softmax')
lookup_outputs = [lookup.apply(input) for lookup, input in zip(lookups, inputs)]
m = merge.apply(*lookup_outputs)
r = linear0.apply(m)
for block in recurrent_blocks:
r = block.apply(r)
a = linear_out.apply(r)
self.Cost = softmax.categorical_cross_entropy(output, a, extra_ndim=1).mean()
self.Cost.name = 'cost'
y_hat = softmax.apply(a, extra_ndim=1)
y_hat.name = 'y_hat'
self.ComputationGraph = ComputationGraph(self.Cost)
self.Function = None
self.MainLoop = None
self.Model = Model(y_hat)
rnn = SimpleRecurrent(
name='hidden',
dim=hidden_layer_dim,
activation=Tanh(),
weights_init=initialization.Uniform(width=0.01))
rnn.initialize()
linear_output = Linear(
name='linear_output',
input_dim=hidden_layer_dim,
output_dim=charset_size,
weights_init=initialization.Uniform(width=0.01),
biases_init=Constant(0))
linear_output.initialize()
softmax = NDimensionalSoftmax(name='ndim_softmax')
activation_input = lookup_input.apply(x)
hidden = rnn.apply(linear_input.apply(activation_input))
activation_output = linear_output.apply(hidden)
y_est = softmax.apply(activation_output, extra_ndim=1)
cost = softmax.categorical_cross_entropy(y, activation_output, extra_ndim=1).mean()
from blocks.graph import ComputationGraph
from blocks.algorithms import GradientDescent, Adam
cg = ComputationGraph([cost])
step_rules = [RMSProp(learning_rate=0.002, decay_rate=0.95), StepClipping(1.0)]
parser.add_argument('-temperature', type=float,
default=1.0, help='temperature of sampling')
args = parser.parse_args()
# Define primetext
ix_to_char, char_to_ix, vocab_size = get_metadata(hdf5_file)
if args.primetext and len(args.primetext) > 0:
primetext = ''.join(
[ch for ch in args.primetext if ch in char_to_ix.keys()])
x_curr = numpy.expand_dims(
numpy.array([char_to_ix[ch] for ch in primetext], dtype='uint8'), axis=1)
else:
dev_stream = get_stream(hdf5_file, 'dev', batch_size)
x_curr, y_curr = dev_stream.get_epoch_iterator().next()
x_curr = x_curr[:, -1].reshape(seq_length, 1)
print 'Loading model from {0}...'.format(args.model)
main_loop = load(args.model)
print 'Model loaded. Building prediction function...'
model = main_loop.model
y, x = model.inputs
softmax = NDimensionalSoftmax()
linear_output = [
v for v in model.variables if v.name == 'linear_output'][0]
y_hat = softmax.apply(linear_output, extra_ndim=1)
predict = theano.function([x], y_hat)
print 'Starting sampling'
sample_string = sample(args.length, x_curr, predict, ix_to_char,
seed=args.seed, temperature=args.temperature)
class CharRNNModel(Initializable):
"""
A model for testing that the components of my more complex models work.
This is just a model that predicts one character at a time using a LSTM layer
"""
def __init__(self, config_dict, init_type="xavier", **kwargs):
super(CharRNNModel, self).__init__(**kwargs)
self.batch_size = config_dict["batch_size"]
self.num_subwords = config_dict["num_subwords"]
self.num_words = config_dict["num_words"]
self.subword_embedding_size = config_dict["subword_embedding_size"]
self.input_vocab_size = config_dict["input_vocab_size"]
self.output_vocab_size = config_dict["output_vocab_size"]
self.subword_RNN_hidden_state_size = config_dict["subword_RNN_hidden_state_size"]
self.table_width = config_dict["table_width"]
self.max_out_dim = config_dict["max_out_dim"]
self.max_out_K = config_dict["max_out_K"]
self.lookup = LookupTable(length=self.input_vocab_size, dim=self.subword_embedding_size, name="input_lookup")
self.lookup.weights_init = Uniform(width=self.table_width)
self.lookup.biases_init = Constant(0)
if init_type == "xavier":
linear_init = XavierInitializationOriginal(self.subword_embedding_size, self.subword_RNN_hidden_state_size)
lstm_init = XavierInitializationOriginal(self.subword_embedding_size, self.subword_RNN_hidden_state_size)
else: # default is gaussian
linear_init = IsotropicGaussian()
lstm_init = IsotropicGaussian()
# The `inputs` are then split in this order: Input gates, forget gates, cells and output gates
self.linear_forward = Linear(
input_dim=self.subword_embedding_size,
output_dim=self.subword_RNN_hidden_state_size * 4,
name="linear_forward",
weights_init=linear_init,
biases_init=Constant(0.0),
)
self.language_model = LSTM(
dim=self.subword_RNN_hidden_state_size,
activation=Tanh(),
name="language_model_RNN",
weights_init=lstm_init,
biases_init=Constant(0.0),
)
self.max_out = LinearMaxout(
self.subword_RNN_hidden_state_size,
self.max_out_dim,
self.max_out_K,
name="max_out",
weights_init=IsotropicGaussian(),
biases_init=Constant(0.0),
)
self.softmax_linear = Linear(
self.max_out_dim,
self.output_vocab_size,
name="soft_max_linear",
weights_init=IsotropicGaussian(),
biases_init=Constant(0.0),
)
self.softmax = NDimensionalSoftmax()
self.children = [
self.lookup,
self.linear_forward,
self.language_model,
self.max_out,
self.softmax_linear,
self.softmax,
]
@application(inputs=["features", "features_mask", "targets", "targets_mask"], outputs=["cost"])
def apply(self, features, features_mask, targets, targets_mask):
subword_embeddings = self.lookup.apply(features)
sentence_embeddings = self.language_model.apply(
self.linear_forward.apply(subword_embeddings), mask=features_mask
)[
0
] # [0] = hidden states, [1] = cells
linear_output = self.softmax_linear.apply(self.max_out.apply(sentence_embeddings))
cost = self.softmax.categorical_cross_entropy(targets, linear_output, extra_ndim=1).mean()
cost.name = "cost"
return ((cost * targets_mask).sum()) / targets_mask.sum()
def __init__(self, initial_output=0, **kwargs):
self.initial_output = initial_output
self.softmax = NDimensionalSoftmax()
children = [self.softmax]
kwargs.setdefault('children', []).extend(children)
super(SoftmaxEmitter, self).__init__(**kwargs)
def __init__(self, initial_output=0, **kwargs):
super(SoftmaxEmitter, self).__init__(**kwargs)
self.initial_output = initial_output
self.softmax = NDimensionalSoftmax()
self.children = [self.softmax]
def __init__(
self,
dim,
emb_dim,
vocab,
def_emb_translate_dim=-1,
def_dim=-1,
encoder='bilstm',
bn=True,
def_reader=None,
def_combiner=None,
dropout=0.5,
num_input_words=-1,
# Others
**kwargs):
self._dropout = dropout
self._vocab = vocab
self._emb_dim = emb_dim
self._def_reader = def_reader
self._def_combiner = def_combiner
if encoder != 'bilstm':
raise NotImplementedError()
if def_emb_translate_dim < 0:
self.def_emb_translate_dim = emb_dim
else:
self.def_emb_translate_dim = def_emb_translate_dim
if def_dim < 0:
self._def_dim = emb_dim
else:
self._def_dim = def_dim
if num_input_words > 0:
logger.info("Restricting vocab to " + str(num_input_words))
self._num_input_words = num_input_words
else:
self._num_input_words = vocab.size()
children = []
if self.def_emb_translate_dim != self._emb_dim:
self._translate_pre_def = Linear(input_dim=emb_dim,
output_dim=def_emb_translate_dim)
children.append(self._translate_pre_def)
else:
self._translate_pre_def = None
## Embedding
self._lookup = LookupTable(self._num_input_words,
emb_dim,
weights_init=GlorotUniform())
children.append(self._lookup)
if def_reader:
self._final_emb_dim = self._def_dim
self._def_reader = def_reader
self._def_combiner = def_combiner
children.extend([self._def_reader, self._def_combiner])
else:
self._final_emb_dim = self._emb_dim
## BiLSTM
self._hyp_bidir_fork = Linear(
self._def_dim if def_reader else self._emb_dim,
4 * dim,
name='hyp_bidir_fork')
self._hyp_bidir = Bidirectional(LSTM(dim), name='hyp_bidir')
self._prem_bidir_fork = Linear(
self._def_dim if def_reader else self._emb_dim,
4 * dim,
name='prem_bidir_fork')
self._prem_bidir = Bidirectional(LSTM(dim), name='prem_bidir')
children.extend([self._hyp_bidir_fork, self._hyp_bidir])
children.extend([self._prem_bidir, self._prem_bidir_fork])
## BiLSTM no. 2 (encoded attentioned embeddings)
self._hyp_bidir_fork2 = Linear(8 * dim,
4 * dim,
name='hyp_bidir_fork2')
self._hyp_bidir2 = Bidirectional(LSTM(dim), name='hyp_bidir2')
self._prem_bidir_fork2 = Linear(8 * dim,
4 * dim,
name='prem_bidir_fork2')
self._prem_bidir2 = Bidirectional(LSTM(dim), name='prem_bidir2')
children.extend([self._hyp_bidir_fork2, self._hyp_bidir2])
children.extend([self._prem_bidir2, self._prem_bidir_fork2])
self._rnns = [
self._prem_bidir2, self._hyp_bidir2, self._prem_bidir,
self._hyp_bidir
]
## MLP
if bn:
self._mlp = BatchNormalizedMLP([Tanh()], [8 * dim, dim],
conserve_memory=False,
name="mlp")
self._pred = BatchNormalizedMLP([Softmax()], [dim, 3],
conserve_memory=False,
name="pred_mlp")
else:
self._mlp = MLP([Tanh()], [8 * dim, dim], name="mlp")
self._pred = MLP([Softmax()], [dim, 3], name="pred_mlp")
children.append(self._mlp)
children.append(self._pred)
## Softmax
self._ndim_softmax = NDimensionalSoftmax()
children.append(self._ndim_softmax)
super(ESIM, self).__init__(children=children, **kwargs)
linear_input.initialize()
rnn = SimpleRecurrent(name='hidden',
dim=hidden_layer_dim,
activation=Tanh(),
weights_init=initialization.Uniform(width=0.01))
rnn.initialize()
linear_output = Linear(name='linear_output',
input_dim=hidden_layer_dim,
output_dim=train_dataset.durations_vocab_size(),
weights_init=initialization.Uniform(width=0.01),
biases_init=Constant(0))
linear_output.initialize()
softmax = NDimensionalSoftmax(name='ndim_softmax')
activation_input = lookup_input.apply(x)
hidden = rnn.apply(linear_input.apply(activation_input))
activation_output = linear_output.apply(hidden)
y_est = softmax.apply(activation_output, extra_ndim=1)
cost = softmax.categorical_cross_entropy(y, activation_output,
extra_ndim=1).mean()
from blocks.graph import ComputationGraph
from blocks.algorithms import GradientDescent, Adam
cg = ComputationGraph([cost])
step_rules = [RMSProp(learning_rate=0.002, decay_rate=0.95), StepClipping(1.0)]
def __init__(self, initial_output=0, **kwargs):
self.initial_output = initial_output
self.softmax = NDimensionalSoftmax()
children = [self.softmax] + kwargs.get('children', [])
super(SoftmaxEmitter, self).__init__(children=children, **kwargs)
def __init__(self, dim, emb_dim, readout_dims, num_input_words,
def_num_input_words, vocab, use_definitions, def_word_gating,
compose_type, coattention, def_reader, reuse_word_embeddings,
random_unk, **kwargs):
self._vocab = vocab
if emb_dim == 0:
emb_dim = dim
if num_input_words == 0:
num_input_words = vocab.size()
if def_num_input_words == 0:
def_num_input_words = num_input_words
self._coattention = coattention
self._num_input_words = num_input_words
self._use_definitions = use_definitions
self._random_unk = random_unk
self._reuse_word_embeddings = reuse_word_embeddings
lookup_num_words = num_input_words
if reuse_word_embeddings:
lookup_num_words = max(num_input_words, def_num_input_words)
if random_unk:
lookup_num_words = vocab.size()
# Dima: we can have slightly less copy-paste here if we
# copy the RecurrentFromFork class from my other projects.
children = []
self._lookup = LookupTable(lookup_num_words, emb_dim)
self._encoder_fork = Linear(emb_dim, 4 * dim, name='encoder_fork')
self._encoder_rnn = LSTM(dim, name='encoder_rnn')
self._question_transform = Linear(dim, dim, name='question_transform')
self._bidir_fork = Linear(3 * dim if coattention else 2 * dim,
4 * dim,
name='bidir_fork')
self._bidir = Bidirectional(LSTM(dim), name='bidir')
children.extend([
self._lookup, self._encoder_fork, self._encoder_rnn,
self._question_transform, self._bidir, self._bidir_fork
])
activations = [Rectifier()] * len(readout_dims) + [None]
readout_dims = [2 * dim] + readout_dims + [1]
self._begin_readout = MLP(activations,
readout_dims,
name='begin_readout')
self._end_readout = MLP(activations, readout_dims, name='end_readout')
self._softmax = NDimensionalSoftmax()
children.extend(
[self._begin_readout, self._end_readout, self._softmax])
if self._use_definitions:
# A potential bug here: we pass the same vocab to the def reader.
# If a different token is reserved for UNK in text and in the definitions,
# we can be screwed.
def_reader_class = eval(def_reader)
def_reader_kwargs = dict(
num_input_words=def_num_input_words,
dim=dim,
emb_dim=emb_dim,
vocab=vocab,
lookup=self._lookup if reuse_word_embeddings else None)
if def_reader_class == MeanPoolReadDefinitions:
def_reader_kwargs.update(dict(normalize=True, translate=False))
self._def_reader = def_reader_class(**def_reader_kwargs)
self._combiner = MeanPoolCombiner(dim=dim,
emb_dim=emb_dim,
def_word_gating=def_word_gating,
compose_type=compose_type)
children.extend([self._def_reader, self._combiner])
super(ExtractiveQAModel, self).__init__(children=children, **kwargs)
# create default input variables
self.contexts = tensor.lmatrix('contexts')
self.context_mask = tensor.matrix('contexts_mask')
self.questions = tensor.lmatrix('questions')
self.question_mask = tensor.matrix('questions_mask')
self.answer_begins = tensor.lvector('answer_begins')
self.answer_ends = tensor.lvector('answer_ends')
input_vars = [
self.contexts, self.context_mask, self.questions,
self.question_mask, self.answer_begins, self.answer_ends
]
if self._use_definitions:
self.defs = tensor.lmatrix('defs')
self.def_mask = tensor.matrix('def_mask')
self.contexts_def_map = tensor.lmatrix('contexts_def_map')
self.questions_def_map = tensor.lmatrix('questions_def_map')
input_vars.extend([
self.defs, self.def_mask, self.contexts_def_map,
self.questions_def_map
])
self.input_vars = OrderedDict([(var.name, var) for var in input_vars])
def fit(self, trainset, retrain=True):
batch_size = self.batch_size
n_iter = self.n_iter
look_ahead = self.look_ahead
lr = self.lr
b1 = self.b1
b2 = self.b2
epsilon = self.epsilon
hidden_size = self.hidden_size
activation_function = self.activation_function
drop_rate = self.drop_rate
weight_decay = self.weight_decay
optimizer = self.optimizer
std = self.std
alpha = self.alpha
polyak_mu = self.polyak_mu
rating_category = self.rating_category
item_num = self.item_num
user_num = self.user_num
trainset = self.load_dataset(which_set=['train'],
sources=('input_ratings',
'output_ratings', 'input_masks',
'output_masks'))
validset = self.load_dataset(which_set=['valid'],
sources=('input_ratings',
'output_ratings', 'input_masks',
'output_masks'))
train_loop_stream = ForceFloatX(data_stream=MovieLensTransformer(
data_stream=Trainer_MovieLensTransformer(data_stream=DataStream(
dataset=trainset,
iteration_scheme=ShuffledScheme(trainset.num_examples,
batch_size)))))
valid_monitor_stream = ForceFloatX(data_stream=MovieLensTransformer(
data_stream=DataStream(dataset=validset,
iteration_scheme=ShuffledScheme(
validset.num_examples, batch_size))))
rating_freq = np.zeros((user_num, rating_category))
init_b = np.zeros((user_num, rating_category))
for batch in valid_monitor_stream.get_epoch_iterator():
inp_r, out_r, inp_m, out_m = batch
rating_freq += inp_r.sum(axis=0)
log_rating_freq = np.log(rating_freq + 1e-8)
log_rating_freq_diff = np.diff(log_rating_freq, axis=1)
init_b[:, 1:] = log_rating_freq_diff
init_b[:, 0] = log_rating_freq[:, 0]
# init_b = np.log(rating_freq / (rating_freq.sum(axis=1)[:, None] + 1e-8) +1e-8) * (rating_freq>0)
new_items = np.where(rating_freq.sum(axis=1) == 0)[0]
self.new_items = new_items
input_ratings = T.tensor3(name='input_ratings',
dtype=theano.config.floatX)
output_ratings = T.tensor3(name='output_ratings',
dtype=theano.config.floatX)
input_masks = T.matrix(name='input_masks', dtype=theano.config.floatX)
output_masks = T.matrix(name='output_masks',
dtype=theano.config.floatX)
input_ratings_cum = T.extra_ops.cumsum(input_ratings[:, :, ::-1],
axis=2)[:, :, ::-1]
# hidden_size = [256]
if activation_function == 'reclin':
act = Rectifier
elif activation_function == 'tanh':
act = Tanh
elif activation_function == 'sigmoid':
act = Logistic
else:
act = Softplus
layers_act = [act('layer_%d' % i) for i in range(len(hidden_size))]
NADE_CF_model = tabula_NADE(activations=layers_act,
input_dim0=user_num,
input_dim1=rating_category,
other_dims=hidden_size,
batch_size=batch_size,
weights_init=Uniform(std=0.05),
biases_init=Constant(0.0))
NADE_CF_model.push_initialization_config()
dims = [user_num] + hidden_size + [user_num]
linear_layers = [
layer for layer in NADE_CF_model.children if 'linear' in layer.name
]
assert len(linear_layers) == len(dims) - 1
for i in range(len(linear_layers)):
H1 = dims[i]
H2 = dims[i + 1]
width = 2 * np.sqrt(6) / np.sqrt(H1 + H2)
# std = np.sqrt(2. / dim)
linear_layers[i].weights_init = Uniform(width=width)
NADE_CF_model.initialize()
NADE_CF_model.children[-1].parameters[-1].set_value(
init_b.astype(theano.config.floatX))
y = NADE_CF_model.apply(input_ratings_cum)
y_cum = T.extra_ops.cumsum(y, axis=2)
predicted_ratings = NDimensionalSoftmax().apply(y_cum, extra_ndim=1)
d = input_masks.sum(axis=1)
D = (input_masks + output_masks).sum(axis=1)
cost, nll, nll_item_ratings, cost_ordinal_1N, cost_ordinal_N1, prob_item_ratings = rating_cost(
y,
output_ratings,
input_masks,
output_masks,
D,
d,
alpha=alpha,
std=std)
cost.name = 'cost'
cg = ComputationGraph(cost)
if weight_decay > 0.0:
all_weights = VariableFilter(roles=[WEIGHT])(cg.variables)
l2_weights = T.sum([(W**2).sum() for W in all_weights])
l2_cost = cost + weight_decay * l2_weights
l2_cost.name = 'l2_decay_' + cost.name
cg = ComputationGraph(l2_cost)
if drop_rate > 0.0:
dropped_layer = VariableFilter(roles=[INPUT],
bricks=NADE_CF_model.children)(
cg.variables)
dropped_layer = [
layer for layer in dropped_layer if 'linear' in layer.name
]
dropped_layer = dropped_layer[1:]
cg_dropout = apply_dropout(cg, dropped_layer, drop_rate)
else:
cg_dropout = cg
training_cost = cg_dropout.outputs[0]
lr0 = T.scalar(name='learning_rate', dtype=theano.config.floatX)
input_list = [input_ratings, input_masks, output_ratings, output_masks]
if optimizer == 'Adam':
f_get_grad, f_update_parameters, shared_gradients = Adam_optimizer(
input_list, training_cost, cg_dropout.parameters, lr0, b1, b2,
epsilon)
elif optimizer == 'Adadelta':
f_get_grad, f_update_parameters, shared_gradients = Adadelta_optimizer(
input_list, training_cost, cg_dropout.parameters, lr, epsilon)
else:
f_get_grad, f_update_parameters, shared_gradients = SGD_optimizer(
input_list, training_cost, cg_dropout.parameters, lr0, b1)
param_list = []
[param_list.extend(p.parameters) for p in NADE_CF_model.children]
f_update_polyak, shared_polyak = polyak(param_list, mu=polyak_mu)
f_monitor = theano.function(inputs=[input_ratings],
outputs=[predicted_ratings])
nb_of_epocs_without_improvement = 0
best_valid_error = np.Inf
epoch = 0
best_model = cp.deepcopy(NADE_CF_model)
best_polyak = cp.deepcopy(shared_polyak)
start_training_time = t.time()
lr_tracer = []
rate_score = np.array(list(range(1, rating_category + 1)), np.float32)
best_epoch = -1
while epoch < n_iter and nb_of_epocs_without_improvement < look_ahead:
print('Epoch {0}'.format(epoch))
epoch += 1
start_time_epoch = t.time()
cost_train = []
squared_error_train = []
n_sample_train = []
cntt = 0
train_time = 0
for batch in train_loop_stream.get_epoch_iterator():
inp_r, out_r, inp_m, out_m = batch
train_t = t.time()
cost_value = f_get_grad(inp_r, inp_m, out_r, out_m)
train_time += t.time() - train_t
# pred_ratings = f_monitor(inp_r)
if optimizer == 'Adadelta':
f_update_parameters()
else:
f_update_parameters(lr)
f_update_polyak()
pred_ratings = f_monitor(inp_r)
true_r = out_r.argmax(axis=2) + 1
pred_r = (pred_ratings[0] *
rate_score[np.newaxis, np.newaxis, :]).sum(axis=2)
pred_r[:, new_items] = 3
mask = out_r.sum(axis=2)
se = np.sum(np.square(true_r - pred_r) * mask)
n = np.sum(mask)
squared_error_train.append(se)
n_sample_train.append(n)
cost_train.append(cost_value)
cntt += 1
cost_train = np.array(cost_train).mean()
squared_error_ = np.array(squared_error_train).sum()
n_samples = np.array(n_sample_train).sum()
train_RMSE = np.sqrt(squared_error_ / (n_samples * 1.0 + 1e-8))
print('\tTraining ...')
print('Train :', "RMSE: {0:.6f}".format(train_RMSE),
" Cost Error: {0:.6f}".format(cost_train),
"Train Time: {0:.6f}".format(train_time),
get_done_text(start_time_epoch))
print('\tValidating ...', )
start_time = t.time()
squared_error_valid = []
n_sample_valid = []
valid_time = 0
for batch in valid_monitor_stream.get_epoch_iterator():
inp_r, out_r, inp_m, out_m = batch
valid_t = t.time()
pred_ratings = f_monitor(inp_r)
valid_time += t.time() - valid_t
true_r = out_r.argmax(axis=2) + 1
pred_r = (pred_ratings[0] *
rate_score[np.newaxis, np.newaxis, :]).sum(axis=2)
pred_r[:, new_items] = 3
mask = out_r.sum(axis=2)
se = np.sum(np.square(true_r - pred_r) * mask)
n = np.sum(mask)
squared_error_valid.append(se)
n_sample_valid.append(n)
squared_error_ = np.array(squared_error_valid).sum()
n_samples = np.array(n_sample_valid).sum()
valid_RMSE = np.sqrt(squared_error_ / (n_samples * 1.0 + 1e-8))
print('Validation:', " RMSE: {0:.6f}".format(valid_RMSE),
"Valid Time: {0:.6f}".format(valid_time),
get_done_text(start_time))
if valid_RMSE < best_valid_error:
best_epoch = epoch
nb_of_epocs_without_improvement = 0
best_valid_error = valid_RMSE
del best_model
del best_polyak
gc.collect()
best_model = cp.deepcopy(NADE_CF_model)
best_polyak = cp.deepcopy(shared_polyak)
print('\n\n Got a good one')
else:
nb_of_epocs_without_improvement += 1
if optimizer == 'Adadelta':
pass
elif nb_of_epocs_without_improvement == look_ahead and lr > 1e-5:
nb_of_epocs_without_improvement = 0
lr /= 4
print("learning rate is now %s" % lr)
lr_tracer.append(lr)
print('\n### Training, n_layers=%d' % (len(hidden_size)),
get_done_text(start_training_time))
best_y = best_model.apply(input_ratings_cum)
best_y_cum = T.extra_ops.cumsum(best_y, axis=2)
best_predicted_ratings = NDimensionalSoftmax().apply(best_y_cum,
extra_ndim=1)
self.f_monitor_best = theano.function(inputs=[input_ratings],
outputs=[best_predicted_ratings])
self.best_valid_error = best_valid_error
self.best_epoch = best_epoch
self.best_model = best_model
self.best_polyak = best_polyak
MaxPooling((2, 2), name='MaxPol1'),
Convolutional(filter_size=(1, 1), num_filters=1024, name='Convx3'),
Rectifier(),
MaxPooling((2, 2), name='MaxPol2'),
Convolutional(filter_size=(1, 1), num_filters=2, name='Convx4'),
Rectifier(),
])
conv_sequence1 = ConvolutionalSequence(conv_layers1,
num_channels=512,
image_size=(10, 10),
weights_init=Orthogonal(),
use_bias=False,
name='ConvSeq3')
conv_sequence1.initialize()
out_soft1 = Flattener(name='Flatt1').apply(conv_sequence1.apply(out5))
predict1 = NDimensionalSoftmax(name='Soft1').apply(out_soft1)
cost1 = CategoricalCrossEntropy(name='Cross1').apply(
y.flatten(), predict1).copy(name='cost1')
#SECOND SOFTMAX
conv_layers2 = list([
MaxPooling((2, 2), name='MaxPol2'),
Convolutional(filter_size=(1, 1), num_filters=128, name='Convx21'),
Rectifier(),
MaxPooling((2, 2), name='MaxPol11'),
Convolutional(filter_size=(1, 1), num_filters=1024, name='Convx31'),
Rectifier(),
MaxPooling((2, 2), name='MaxPol21'),
Convolutional(filter_size=(1, 1), num_filters=2, name='Convx41'),
Rectifier(),
])
H1 = dims[i]
H2 = dims[i + 1]
width = 2 * np.sqrt(6) / np.sqrt(H1 + H2)
# std = np.sqrt(2. / dim)
linear_layers[i].weights_init = Uniform(width=width)
# NADE_CF_model.children[0].weights_init = Constant(1)
# NADE_CF_model.children[0].biases_init = Constant(1.5)
# NADE_CF_model.children[1].weights_init = Constant(2)
# NADE_CF_model.children[1].biases_init = Constant(2.5)
NADE_CF_model.initialize()
NADE_CF_model.children[-1].parameters[-1].set_value(
init_b.astype(theano.config.floatX))
y = NADE_CF_model.apply(input_ratings_cum)
y_cum = T.extra_ops.cumsum(y, axis=2)
predicted_ratings = NDimensionalSoftmax().apply(y_cum, extra_ndim=1)
d = input_masks.sum(axis=1)
D = (input_masks + output_masks).sum(axis=1)
# ratings = T.tensor3(name="ratings", dtype=theano.config.floatX)
cost, nll, nll_item_ratings, cost_ordinal_1N, cost_ordinal_N1, prob_item_ratings = rating_cost(
y,
output_ratings,
input_masks,
output_masks,
D,
d,
alpha=alpha,
std=std)
cost.name = 'cost'
cg = ComputationGraph(cost)
# ******************* Model *******************
recognizer = SimpleSpeechRecognizer(transition=transition,
dims_transition=conf.dims_transition,
num_features=num_features, num_classes=num_classes)
#recognizer = SpeechRecognizer(
# num_features=num_features, dims_bottom=[],
# dims_bidir=conf.dims_transition, dims_top=[num_classes],
# bidir_trans=GatedRecurrent, bottom_activation=None)
# ******************* output *******************
y_hat = recognizer.apply(x,x_m)
y_hat.name = 'outputs'
y_hat_softmax = NDimensionalSoftmax().apply(y_hat, extra_ndim = y_hat.ndim - 2)
y_hat_softmax.name = 'outputs_softmax'
# there is a cost function for monitoring and for training, because one is more stable to compute
# gradients and seems also to be more memory efficient, but does not compute the true cost.
if conf.task=='CTC':
cost_train = ctc.pseudo_cost(y, y_hat, y_m, x_m).mean()
cost_train.name = "cost_train"
cost_monitor = ctc.cost(y, y_hat_softmax, y_m, x_m).mean()
cost_monitor.name = "cost_monitor"
elif conf.task=='framewise':
cost_train = categorical_crossentropy_batch().apply(y_hat_softmax, y, x_m)
cost_train.name='cost'
cost_monitor = cost_train
else:
class FRNNEmitter(AbstractEmitter, Initializable, Random):
"""An RNN emitter for the case of real outputs.
Parameters
----------
"""
def __init__(self, mlp, target_size, frame_size, k, frnn_hidden_size, frnn_step_size, const=1e-5, **kwargs):
super(FRNNEmitter, self).__init__(**kwargs)
self.mlp = mlp
self.target_size = target_size
self.frame_size = frame_size
self.k = k
self.frnn_hidden_size = frnn_hidden_size
self.const = const
self.input_dim = self.mlp.output_dim
self.frnn_step_size = frnn_step_size
# adding a step if the division is not exact.
self.number_of_steps = frame_size // frnn_step_size
self.last_steps = frame_size % frnn_step_size
if self.last_steps != 0:
self.number_of_steps += 1
self.mu = MLP(activations=[Identity()], dims=[frnn_hidden_size, k * frnn_step_size], name=self.name + "_mu")
self.sigma = MLP(
activations=[SoftPlus()], dims=[frnn_hidden_size, k * frnn_step_size], name=self.name + "_sigma"
)
self.coeff = MLP(activations=[Identity()], dims=[frnn_hidden_size, k], name=self.name + "_coeff")
self.coeff2 = NDimensionalSoftmax()
self.frnn_initial_state = Linear(
input_dim=self.input_dim, output_dim=frnn_hidden_size, name="frnn_initial_state"
)
# self.frnn_hidden = Linear(
# input_dim=frnn_hidden_size,
# output_dim=frnn_hidden_size,
# activation=Tanh(),
# name="frnn_hidden")
self.frnn_activation = Tanh(name="frnn_activation")
self.frnn_linear_transition_state = Linear(
input_dim=frnn_hidden_size, output_dim=frnn_hidden_size, name="frnn_linear_transition_state"
)
self.frnn_linear_transition_input = Linear(
input_dim=self.frnn_step_size, output_dim=frnn_hidden_size, name="frnn_linear_transition_input"
)
# self.frnn_linear_transition_output = Linear (
# input_dim = frnn_hidden_size,
# output_dim = self.rnn_hidden_dim,
# name="frnn_linear_transition_output")
self.children = [
self.mlp,
self.mu,
self.sigma,
self.coeff,
self.coeff2,
self.frnn_initial_state,
self.frnn_activation,
self.frnn_linear_transition_state,
self.frnn_linear_transition_input,
]
@application
def emit(self, readouts):
"""
keep_parameters is True if mu,sigma,coeffs must be stacked and returned
if false, only the result is given, the others will be empty list.
"""
# initial state
state = self.frnn_initial_state.apply(self.mlp.apply(readouts))
results = []
for i in range(self.number_of_steps):
last_iteration = i == self.number_of_steps - 1
# First generating distribution parameters and sampling.
mu = self.mu.apply(state)
sigma = self.sigma.apply(state) + self.const
coeff = self.coeff2.apply(self.coeff.apply(state), extra_ndim=state.ndim - 2) + self.const
shape_result = coeff.shape
shape_result = tensor.set_subtensor(shape_result[-1], self.frnn_step_size)
ndim_result = coeff.ndim
mu = mu.reshape((-1, self.frnn_step_size, self.k))
sigma = sigma.reshape((-1, self.frnn_step_size, self.k))
coeff = coeff.reshape((-1, self.k))
sample_coeff = self.theano_rng.multinomial(pvals=coeff, dtype=coeff.dtype)
idx = predict(sample_coeff, axis=-1)
# idx = predict(coeff, axis = -1) use this line for using most likely coeff.
# shapes (ls*bs)*(fs)
mu = mu[tensor.arange(mu.shape[0]), :, idx]
sigma = sigma[tensor.arange(sigma.shape[0]), :, idx]
epsilon = self.theano_rng.normal(size=mu.shape, avg=0.0, std=1.0, dtype=mu.dtype)
result = mu + sigma * epsilon # *0.6 #reduce variance.
result = result.reshape(shape_result, ndim=ndim_result)
results.append(result)
# if the total size does not correspond to the frame_size,
# this removes the need for padding
if not last_iteration:
state = self.frnn_activation.apply(
self.frnn_linear_transition_state.apply(state) + self.frnn_linear_transition_input.apply(result)
)
results = tensor.stack(results, axis=-1)
results = tensor.flatten(results, outdim=results.ndim - 1)
# truncate if not good size
if self.last_steps != 0:
results = results[tuple([slice(0, None)] * (results.ndim - 1) + [slice(0, self.frame_size)])]
return results
@application
def cost(self, readouts, outputs):
# initial state
state = self.frnn_initial_state.apply(self.mlp.apply(readouts))
inputs = outputs
mus = []
sigmas = []
coeffs = []
for i in range(self.number_of_steps):
last_iteration = i == self.number_of_steps - 1
# First generating distribution parameters and sampling.
freq_mu = self.mu.apply(state)
freq_sigma = self.sigma.apply(state) + self.const
freq_coeff = self.coeff2.apply(self.coeff.apply(state), extra_ndim=state.ndim - 2) + self.const
freq_mu = freq_mu.reshape((-1, self.frnn_step_size, self.k))
freq_sigma = freq_sigma.reshape((-1, self.frnn_step_size, self.k))
freq_coeff = freq_coeff.reshape((-1, self.k))
# mu,sigma: shape (-1,fs,k)
# coeff: shape (-1,k)
mus.append(freq_mu)
sigmas.append(freq_sigma)
coeffs.append(freq_coeff)
index = self.frnn_step_size
freq_inputs = inputs[
tuple([slice(0, None)] * (inputs.ndim - 1) + [slice(index, index + self.frnn_step_size)])
]
if not last_iteration:
state = self.frnn_activation.apply(
self.frnn_linear_transition_state.apply(state)
+ self.frnn_linear_transition_input.apply(freq_inputs)
)
mus = tensor.stack(mus, axis=-2)
sigmas = tensor.stack(sigmas, axis=-2)
coeffs = tensor.stack(coeffs, axis=-2)
mus = mus.reshape((-1, self.frnn_step_size * self.number_of_steps, self.k))
sigmas = sigmas.reshape((-1, self.frnn_step_size * self.number_of_steps, self.k))
coeffs = coeffs.repeat(self.frnn_step_size, axis=-2)
mus = mus[tuple([slice(0, None)] * (mus.ndim - 2) + [slice(0, self.frame_size)] + [slice(0, None)])]
sigmas = sigmas[tuple([slice(0, None)] * (sigmas.ndim - 2) + [slice(0, self.frame_size)] + [slice(0, None)])]
coeffs = coeffs[tuple([slice(0, None)] * (coeffs.ndim - 2) + [slice(0, self.frame_size)] + [slice(0, None)])]
# actually prob not necessary
mu = mus.reshape((-1, self.target_size))
sigma = sigmas.reshape((-1, self.target_size))
coeff = coeffs.reshape((-1, self.target_size))
return FRNN_NLL(y=outputs, mu=mu, sig=sigma, coeff=coeff, frame_size=self.frame_size, k=self.k)
@application
def initial_outputs(self, batch_size):
return tensor.zeros((batch_size, self.frame_size), dtype=floatX)
def get_dim(self, name):
# modification here to ensure the right dim.
if name == "outputs":
return self.frame_size
return super(FRNNEmitter, self).get_dim(name)
def __init__(self, *args, **kwargs):
self.softmax = NDimensionalSoftmax()
super(MinRiskInitialContextSequenceGenerator,
self).__init__(*args, **kwargs)
self.children.append(self.softmax)
class ActorCriticReadout(SoftmaxReadout):
"""Actor-critic
Params
------
bos_token : int
The token used to pad critic input. Critic needs to do
at least one extra step compared to the actor in order
to get the first glimpse of the ground-truth sequence
before predicting the actual values.
"""
def __init__(self,
reward_brick,
compute_targets,
compute_policy,
solve_bellman,
freeze_actor,
freeze_critic,
critic_uses_actor_states,
critic_uses_groundtruth,
critic=None,
critic_burnin_steps=None,
critic_policy_t=None,
entropy_reward_coof=None,
cross_entropy_reward_coof=None,
discount=None,
value_penalty=None,
value_softmax=False,
same_value_for_wrong=False,
accumulate_outputs=False,
use_value_biases=None,
actor_grad_estimate=None,
bos_token=None,
**kwargs):
super(ActorCriticReadout, self).__init__(**kwargs)
self.reward_brick = reward_brick
self.critic = critic
self.freeze_actor = freeze_actor
self.freeze_critic = freeze_critic
self.critic_uses_actor_states = critic_uses_actor_states
self.critic_uses_groundtruth = (critic_uses_groundtruth
if critic_uses_groundtruth is not None
else True)
self.critic_burnin_steps = (critic_burnin_steps
if critic_burnin_steps is not None else 0)
self.value_summand = Linear(output_dim=1, name='summand')
self.softmax_t = 1.
self.critic_policy_t = (critic_policy_t
if critic_policy_t is not None else 1.0)
self.epsilon = 0.
self.discount = (discount if discount is not None else 1.)
self.entropy_reward_coof = (entropy_reward_coof
if entropy_reward_coof is not None else 0.)
self.cross_entropy_reward_coof = (cross_entropy_reward_coof
if cross_entropy_reward_coof
is not None else 0.)
self.value_penalty = value_penalty
self.value_softmax = value_softmax
self.same_value_for_wrong = same_value_for_wrong
self.compute_targets = compute_targets
self.compute_policy = compute_policy
self.solve_bellman = solve_bellman
self.accumulate_outputs = accumulate_outputs
self.use_value_biases = (use_value_biases
if use_value_biases is not None else True)
self.actor_grad_estimate = (actor_grad_estimate
if actor_grad_estimate else 'all_actions')
self.bos_token = bos_token
self.softmax = NDimensionalSoftmax()
self.children += [reward_brick, self.value_summand, self.softmax]
if self.critic:
self.children.append(self.critic)
self.costs.inputs += ['attended', 'attended_mask']
def _push_allocation_config(self):
super(ActorCriticReadout, self)._push_allocation_config()
self.value_summand.input_dim = self.get_dim('attended')
@application
def scores(self, **inputs):
merged = self.merge(**dict_subset(inputs, self.merge_names))
return self.softmax.log_probabilities(merged * self.softmax_t,
extra_ndim=merged.ndim - 2)
@application
def costs(self, application_call, prediction, prediction_mask, groundtruth,
groundtruth_mask, **inputs):
def _prediction_subtensor(data):
if data.ndim != 3:
raise ValueError
flat_data = data.reshape(
(data.shape[0] * data.shape[1], data.shape[2]))
flat_data = flat_data[tensor.arange(flat_data.shape[0]),
prediction.flatten()]
return flat_data.reshape(
(prediction.shape[0], prediction.shape[1]))
attended = disconnected_grad(inputs.pop('attended'))
attended_mask = disconnected_grad(inputs.pop('attended_mask'))
# Compute the rewards
rewards = self.reward_brick.apply(prediction, prediction_mask,
groundtruth, groundtruth_mask)[:, :,
0]
future_rewards = rewards[::-1].cumsum(axis=0)[::-1]
# Compute the critic outputs
if self.critic:
padding = tensor.repeat(tensor.fill(prediction[0:1],
self.bos_token),
1,
axis=0)
mask_padding = tensor.repeat(tensor.fill(prediction_mask[0:1], 1.),
1,
axis=0)
padded_prediction = tensor.concatenate([padding, prediction])
padded_prediction_mask = tensor.concatenate(
[mask_padding, prediction_mask])
if self.critic_uses_groundtruth:
critic_context = groundtruth
critic_context_mask = groundtruth_mask
else:
critic_context = tensor.zeros_like(groundtruth[0:1])
critic_context_mask = tensor.zeros_like(groundtruth_mask[0:1])
critic_kwargs = dict(prediction=padded_prediction,
prediction_mask=padded_prediction_mask,
groundtruth=critic_context,
groundtruth_mask=critic_context_mask,
inputs=critic_context,
inputs_mask=critic_context_mask)
if self.critic_uses_actor_states:
extra_inputs = disconnected_grad(inputs['states'])
# We don't the very last hidden state of the actor
# in extra_inputs. We have to add something instead for the shapes
# to match. It doesn't matter at all, what exactly we add.
critic_kwargs['extra_inputs'] = tensor.concatenate(
[extra_inputs,
tensor.zeros_like(extra_inputs[0:1])])
critic_cg = ComputationGraph(self.critic.costs(**critic_kwargs))
outputs, = VariableFilter(
applications=[self.critic.generator.readout.all_outputs],
roles=[OUTPUT])(critic_cg)
# The first subtensor should be discarded, because it was outputted
# for the padding. In addition to that Q-values from the first
# 'critic_burnin_steps' will be ignored, see later in the code.
outputs = outputs[1:]
else:
outputs = self.merge(**dict_subset(inputs, self.merge_names))
prediction_outputs = _prediction_subtensor(outputs)
# Compute Q adjustments
adjustments = outputs
prediction_adjustments = prediction_outputs
if self.accumulate_outputs:
prediction_adjustments = prediction_outputs.cumsum(axis=0)
adjustments = tensor.inc_subtensor(
adjustments[1:], prediction_adjustments[:-1][:, :, None])
# Compute shared additive biases for all Q values
if self.use_value_biases:
value_biases = (self.value_summand.apply(attended)[:, :, 0] *
attended_mask).sum(axis=0)
else:
value_biases = tensor.zeros_like(adjustments[0, :, 0])
values = adjustments + value_biases[None, :, None]
prediction_values = prediction_adjustments + value_biases[None, :]
rolled_prediction_mask = tensor.roll(prediction_mask, -1, axis=0)
rolled_prediction_mask = tensor.set_subtensor(
rolled_prediction_mask[-1], 0)
# Compute probabilities
logs = self.scores(use_epsilon=False, **inputs)
probs = tensor.exp(logs)
if not self.compute_policy:
raise NotImplementedError("Not supported any more")
prediction_logs = _prediction_subtensor(logs)
# Compute value targets
value_targets = (disconnected_grad(probs) * values).sum(axis=-1)
value_targets = tensor.roll(value_targets, -1, axis=0)
value_targets = (
self.discount * value_targets * rolled_prediction_mask + rewards)
value_targets = value_targets.astype(theano.config.floatX)
total_costs = 0
# Compute critic cost
if not self.compute_targets:
logger.debug("Using given targets")
value_targets = tensor.matrix('value_targets')
if self.solve_bellman == 'no':
logger.debug("Not solving Bellman, just predicting the rewards")
value_targets = rewards.copy(name='value_targets')
elif self.solve_bellman == 'without_dp':
future_rewards = rewards[::-1].cumsum(axis=0)[::-1]
logger.debug("Solving Bellman, but without DP")
value_targets = future_rewards
elif self.solve_bellman is not True:
raise ValueError()
critic_costs_per_char = (
(prediction_values - value_targets)**2) * prediction_mask
critic_costs = critic_costs_per_char[self.critic_burnin_steps:].sum(
axis=0)
if not self.freeze_critic:
total_costs += critic_costs
# Compute critic Monte-Carlo cost
critic_monte_carlo_costs = (
(((prediction_values - future_rewards)**2) *
prediction_mask)[self.critic_burnin_steps:].sum(axis=0))
# Value penalty
if self.value_penalty:
logger.debug("Use value penalty")
value_deviations = (values -
values.mean(axis=-1, keepdims=True))**2
if not self.freeze_critic:
total_costs += (
self.value_penalty *
(value_deviations.sum(axis=-1) *
prediction_mask)[self.critic_burnin_steps:].sum(axis=0))
# Compute actor cost
if self.critic:
# The actor cost will be minimized, that's why values
# must be negated.
est_name = self.actor_grad_estimate
if est_name == 'all_actions':
disadvantages = disconnected_grad(
values.max(axis=-1)[:, :, None] - values)
actor_costs = ((probs * disadvantages).sum(axis=-1) *
prediction_mask)
actor_costs = actor_costs[self.critic_burnin_steps:]
elif est_name.startswith('1_action'):
# Here we do not provide a target for the first step for
# the reason we lack an estimate of the value of the initial state.
# This is how our critic works.
# Hopefully the network won't unlearn
# to produce a BOS first.
future_reward_estimate = (future_rewards
if est_name.endswith('unbiased') else
prediction_values)
weights = -disconnected_grad(future_reward_estimate[1:] +
rewards[:-1] -
prediction_values[:-1])
actor_costs = ((prediction_logs[1:] * weights) *
prediction_mask[1:])
actor_costs = actor_costs[self.critic_burnin_steps + 1:]
else:
raise ValueError
actor_costs = actor_costs.sum(axis=0)
actor_entropies = (probs * -logs).sum(axis=-1) * prediction_mask
actor_entropies = actor_entropies[self.critic_burnin_steps:].sum(
axis=0)
critic_policy = disconnected_grad(
self.softmax.apply(self.critic_policy_t * values,
extra_ndim=1))
critic_cross_entropies = ((critic_policy * -logs).sum(axis=-1) *
prediction_mask)
critic_cross_entropies = critic_cross_entropies[
self.critic_burnin_steps:].sum(axis=0)
actor_costs_with_penalties = (
actor_costs - self.entropy_reward_coof * actor_entropies -
self.cross_entropy_reward_coof * critic_cross_entropies)
if not self.freeze_actor:
total_costs += actor_costs_with_penalties
else:
total_costs += disconnected_grad(actor_costs_with_penalties)
# Add auxiliary variables for intermediate steps of the computation
application_call.add_auxiliary_variable(rewards, name='rewards')
application_call.add_auxiliary_variable(value_biases,
name='value_biases')
application_call.add_auxiliary_variable(values.copy(), name='values')
application_call.add_auxiliary_variable(outputs.copy(), name='outputs')
application_call.add_auxiliary_variable(prediction_values,
name='prediction_values')
application_call.add_auxiliary_variable(prediction_outputs,
name='prediction_outputs')
application_call.add_auxiliary_variable(value_targets.copy(),
name='value_targets')
application_call.add_auxiliary_variable(probs.copy(), name='probs')
application_call.add_auxiliary_variable(prediction_logs,
name='prediction_log_probs')
# Compute some statistics for debugging
last_character_mask = prediction_mask - rolled_prediction_mask
last_character_costs = (critic_costs_per_char *
last_character_mask).sum(axis=0)
mean2_output = (((prediction_outputs**2) * prediction_mask).sum() /
prediction_mask.sum())**0.5
max_output = abs(prediction_outputs * prediction_mask).max()
expected_reward = (probs[0] * values[0]).sum(axis=-1)
application_call.add_auxiliary_variable(last_character_costs,
name='last_character_costs')
application_call.add_auxiliary_variable(critic_costs.mean(),
name='mean_critic_cost')
application_call.add_auxiliary_variable(
critic_monte_carlo_costs.mean(),
name='mean_critic_monte_carlo_cost')
if self.critic:
application_call.add_auxiliary_variable(actor_costs.mean(),
name='mean_actor_cost')
application_call.add_auxiliary_variable(actor_entropies.mean(),
name='mean_actor_entropy')
application_call.add_auxiliary_variable(expected_reward.mean(),
name='mean_expected_reward')
application_call.add_auxiliary_variable(mean2_output,
name='mean2_output')
application_call.add_auxiliary_variable(max_output, name='max_output')
return total_costs
def __init__(self, initial_output=0, **kwargs):
super(SoftmaxEmitter, self).__init__(**kwargs)
self.initial_output = initial_output
self.softmax = NDimensionalSoftmax()
self.children = [self.softmax]
def __init__(self,
reward_brick,
compute_targets,
compute_policy,
solve_bellman,
freeze_actor,
freeze_critic,
critic_uses_actor_states,
critic_uses_groundtruth,
critic=None,
critic_burnin_steps=None,
critic_policy_t=None,
entropy_reward_coof=None,
cross_entropy_reward_coof=None,
discount=None,
value_penalty=None,
value_softmax=False,
same_value_for_wrong=False,
accumulate_outputs=False,
use_value_biases=None,
actor_grad_estimate=None,
bos_token=None,
**kwargs):
super(ActorCriticReadout, self).__init__(**kwargs)
self.reward_brick = reward_brick
self.critic = critic
self.freeze_actor = freeze_actor
self.freeze_critic = freeze_critic
self.critic_uses_actor_states = critic_uses_actor_states
self.critic_uses_groundtruth = (critic_uses_groundtruth
if critic_uses_groundtruth is not None
else True)
self.critic_burnin_steps = (critic_burnin_steps
if critic_burnin_steps is not None else 0)
self.value_summand = Linear(output_dim=1, name='summand')
self.softmax_t = 1.
self.critic_policy_t = (critic_policy_t
if critic_policy_t is not None else 1.0)
self.epsilon = 0.
self.discount = (discount if discount is not None else 1.)
self.entropy_reward_coof = (entropy_reward_coof
if entropy_reward_coof is not None else 0.)
self.cross_entropy_reward_coof = (cross_entropy_reward_coof
if cross_entropy_reward_coof
is not None else 0.)
self.value_penalty = value_penalty
self.value_softmax = value_softmax
self.same_value_for_wrong = same_value_for_wrong
self.compute_targets = compute_targets
self.compute_policy = compute_policy
self.solve_bellman = solve_bellman
self.accumulate_outputs = accumulate_outputs
self.use_value_biases = (use_value_biases
if use_value_biases is not None else True)
self.actor_grad_estimate = (actor_grad_estimate
if actor_grad_estimate else 'all_actions')
self.bos_token = bos_token
self.softmax = NDimensionalSoftmax()
self.children += [reward_brick, self.value_summand, self.softmax]
if self.critic:
self.children.append(self.critic)
self.costs.inputs += ['attended', 'attended_mask']