def build_graph(self_attention,
self_penalty,
embeded_dim=60,
h_dim=150,
d_a=350,
r=30):
with C.layers.default_options(init=C.xavier()):
embeded = C.layers.Embedding(embeded_dim)(x)
embeded = C.layers.Stabilizer()(embeded)
H = create_birnn(C.layers.GRU(h_dim), C.layers.GRU(h_dim))(embeded)
if self_attention:
Ws1 = C.parameter(shape=(d_a, 2 * h_dim), name="Ws1")
Ws2 = C.parameter(shape=(r, d_a), name="Ws2")
A = C.softmax(C.times(Ws2, C.tanh(C.times_transpose(Ws1, H))))
H = C.times(A, H) # the M in the paper
if self_penalty:
I = C.constant(np.eye(r), dtype=np.float32)
P = C.times_transpose(A, A) - I # r*r
p = C.reduce_sum(C.abs(C.element_times(
P, P))) # frobenius norm **2
y_ = C.layers.Dense(200, activation=C.ops.relu)(H)
# y_pre = C.layers.Dense(num_labels, activation = None)(y_)
def selfAtt(x):
y_pre = C.layers.Dense(num_labels, activation=None)(y_)
return y_pre
if self_penalty:
selfAtt.p = p
return selfAtt
def create_word2vec_cbow_model(word_one_hot, context_one_hots, negative_one_hots): # shared_embedding_layer = Embedding(G.embedding_dimension, uniform(scale=1.0/2.0/G.embedding_dimension)) shared_embedding_layer = Embedding(G.embedding_dimension) word_embedding = shared_embedding_layer(word_one_hot) context_embeddings = [shared_embedding_layer(x) for x in context_one_hots] negative_embeddings = [shared_embedding_layer(x) for x in negative_one_hots] print(word_embedding.shape) word_embedding_reshaped = C.reshape(word_embedding, shape=(1, G.embedding_dimension)) print(word_embedding_reshaped.shape) context_embeddings_all = C.reshape(C.splice(*context_embeddings), shape=(context_size, G.embedding_dimension)) negative_embeddings_all = C.reshape(C.splice(*negative_embeddings), shape=(G.negative, G.embedding_dimension)) print(context_embeddings_all.shape) print(negative_embeddings_all.shape) cbow = C.reshape(C.reduce_mean(context_embeddings_all, 0), shape=(G.embedding_dimension)) print(cbow.shape) # word_context_product = C.times_transpose(word_embedding_reshaped, cbow) word_context_product = C.times_transpose(word_embedding, cbow) print(word_context_product.shape) negative_context_product = C.reshape(C.times_transpose(negative_embeddings_all, cbow), shape=(G.negative)) print(negative_context_product.shape) word_negative_context_product = C.splice(word_context_product, negative_context_product) print(word_negative_context_product.shape) # return model and shared embedding layer return word_negative_context_product, shared_embedding_layer
def cross_entropy_with_sampled_softmax(
hidden_vector, # Node providing the output of the recurrent layers
target_vector, # Node providing the expected labels (as sparse vectors)
vocab_dim, # Vocabulary size
hidden_dim, # Dimension of the hidden vector
num_samples, # Number of samples to use for sampled softmax
sampling_weights, # Node providing weights to be used for the weighted sampling
allow_duplicates=False # Boolean flag to control whether to use sampling with replacement (allow_duplicates == True) or without replacement.
):
bias = C.layers.Parameter(shape=(vocab_dim, 1), init=0)
weights = C.layers.Parameter(shape=(vocab_dim, hidden_dim),
init=C.initializer.glorot_uniform())
sample_selector_sparse = C.random_sample(
sampling_weights, num_samples,
allow_duplicates) # sparse matrix [num_samples * vocab_size]
if use_sparse:
sample_selector = sample_selector_sparse
else:
# Note: Sampled softmax with dense data is only supported for debugging purposes.
# It might easily run into memory issues as the matrix 'I' below might be quite large.
# In case we wan't to a dense representation for all data we have to convert the sample selector
I = C.Constant(np.eye(vocab_dim, dtype=np.float32))
sample_selector = C.times(sample_selector_sparse, I)
inclusion_probs = C.random_sample_inclusion_frequency(
sampling_weights, num_samples,
allow_duplicates) # dense row [1 * vocab_size]
log_prior = C.log(inclusion_probs) # dense row [1 * vocab_dim]
print("hidden_vector: " + str(hidden_vector.shape))
wS = C.times(sample_selector, weights,
name='wS') # [num_samples * hidden_dim]
print("ws:" + str(wS.shape))
zS = C.times_transpose(wS, hidden_vector, name='zS1') + C.times(
sample_selector, bias, name='zS2') - C.times_transpose(
sample_selector, log_prior, name='zS3') # [num_samples]
# Getting the weight vector for the true label. Dimension hidden_dim
wT = C.times(target_vector, weights, name='wT') # [1 * hidden_dim]
zT = C.times_transpose(wT, hidden_vector, name='zT1') + C.times(
target_vector, bias, name='zT2') - C.times_transpose(
target_vector, log_prior, name='zT3') # [1]
zSReduced = C.reduce_log_sum_exp(zS)
# Compute the cross entropy that is used for training.
# We don't check whether any of the classes in the random samples coincides with the true label, so it might happen that the true class is counted
# twice in the normalizing denominator of sampled softmax.
cross_entropy_on_samples = C.log_add_exp(zT, zSReduced) - zT
# For applying the model we also output a node providing the input for the full softmax
z = C.times_transpose(weights, hidden_vector) + bias
z = C.reshape(z, shape=(vocab_dim))
zSMax = C.reduce_max(zS)
error_on_samples = C.less(zT, zSMax)
return (z, cross_entropy_on_samples, error_on_samples)
def hierarchical_softmax_layer(input_var, label_index, label_dim, label_classes=None):
'''
A two layers hierarchical softmax function:
Args:
input_var: Variable with shape: [#,*](dim_x)
label_index: index of label's category: [#,*](1)
label_dim: number of the label categories
label_classes: number of classes of the label categories
Returns:
output_prob: the probability of the given label [#,*](1)
class_probs: the probability of all the label classes [#,*](label_classes)
all_probs: the probability of all label classes
'''
input_dim = input_var.shape[0]
if not label_classes:
label_classes = int(np.ceil(np.sqrt(float(label_dim))))
n_outputs_per_class = int(np.ceil(label_dim / label_classes))
target_class = C.floor((label_index + 0.5) / n_outputs_per_class)
target_output_in_class = C.round(label_index - target_class * n_outputs_per_class)
w1 = parameter(shape=(input_dim, label_classes), init=C.glorot_normal(), name='hsoftmax_w1')
b1 = parameter(shape=(label_classes), init=C.glorot_normal(), name='hsoftmax_b1')
w2s = parameter(shape=(label_classes, input_dim, n_outputs_per_class,), init=C.glorot_normal(), name='hsoftmax_w2s')
b2s = parameter(shape=(label_classes, n_outputs_per_class,), init=C.glorot_normal(), name='hsoftmax_b2s')
class_probs = softmax(b1 + times(input_var, w1))
# TODO: fix the bug in backprop for sparse, and use sparse embedding to accelerate
target_class_one_hot = C.one_hot(target_class, num_classes=label_classes, sparse_output=False)
w2 = C.reshape(C.times(target_class_one_hot, w2s, output_rank=2), [input_dim, -1])
b2 = C.reshape(times(target_class_one_hot, b2s, output_rank=1), [-1])
probs_in_class = softmax(b2 + times(input_var, w2))
prob_in_class = C.times_transpose(C.one_hot(target_output_in_class, num_classes=n_outputs_per_class, sparse_output=False), probs_in_class)
class_prob = C.times_transpose(C.one_hot(target_class, num_classes=label_classes, sparse_output=False), class_probs)
output_prob = prob_in_class * class_prob
# this is for calculating all the outputs' probabilities
all_probs = []
for i in range(label_classes):
ci = C.constant(i)
ci_one_hot = C.one_hot(ci, num_classes=label_classes, sparse_output=False)
w2a = C.times(ci_one_hot, w2s, output_rank=2)
b2a = C.times(ci_one_hot, b2s, output_rank=1)
probs_in_classa = C.softmax(b2a + times(input_var, w2a))
class_proba = C.times_transpose(ci_one_hot, class_probs)
output_proba = probs_in_classa * class_proba
all_probs.append(output_proba)
return output_prob, class_probs, all_probs
def cross_entropy_with_sampled_softmax(
hidden_vector, # Node providing the output of the recurrent layers
target_vector, # Node providing the expected labels (as sparse vectors)
vocab_dim, # Vocabulary size
hidden_dim, # Dimension of the hidden vector
num_samples, # Number of samples to use for sampled softmax
sampling_weights, # Node providing weights to be used for the weighted sampling
allow_duplicates = False # Boolean flag to control whether to use sampling with replacement (allow_duplicates == True) or without replacement.
):
bias = C.Parameter(shape = (vocab_dim, 1), init = 0)
weights = C.Parameter(shape = (vocab_dim, hidden_dim), init = C.initializer.glorot_uniform())
sample_selector_sparse = C.random_sample(sampling_weights, num_samples, allow_duplicates) # sparse matrix [num_samples * vocab_size]
if use_sparse:
sample_selector = sample_selector_sparse
else:
# Note: Sampled softmax with dense data is only supported for debugging purposes.
# It might easily run into memory issues as the matrix 'I' below might be quite large.
# In case we wan't to a dense representation for all data we have to convert the sample selector
I = C.Constant(np.eye(vocab_dim, dtype=np.float32))
sample_selector = C.times(sample_selector_sparse, I)
inclusion_probs = C.random_sample_inclusion_frequency(sampling_weights, num_samples, allow_duplicates) # dense row [1 * vocab_size]
log_prior = C.log(inclusion_probs) # dense row [1 * vocab_dim]
print("hidden_vector: "+str(hidden_vector.shape))
wS = C.times(sample_selector, weights, name='wS') # [num_samples * hidden_dim]
print("ws:"+str(wS.shape))
zS = C.times_transpose(wS, hidden_vector, name='zS1') + C.times(sample_selector, bias, name='zS2') - C.times_transpose (sample_selector, log_prior, name='zS3')# [num_samples]
# Getting the weight vector for the true label. Dimension hidden_dim
wT = C.times(target_vector, weights, name='wT') # [1 * hidden_dim]
zT = C.times_transpose(wT, hidden_vector, name='zT1') + C.times(target_vector, bias, name='zT2') - C.times_transpose(target_vector, log_prior, name='zT3') # [1]
zSReduced = C.reduce_log_sum_exp(zS)
# Compute the cross entropy that is used for training.
# We don't check whether any of the classes in the random samples coincides with the true label, so it might happen that the true class is counted
# twice in the normalizing denominator of sampled softmax.
cross_entropy_on_samples = C.log_add_exp(zT, zSReduced) - zT
# For applying the model we also output a node providing the input for the full softmax
z = C.times_transpose(weights, hidden_vector) + bias
z = C.reshape(z, shape = (vocab_dim))
zSMax = C.reduce_max(zS)
error_on_samples = C.less(zT, zSMax)
return (z, cross_entropy_on_samples, error_on_samples)
def cross_entropy_with_full_softmax(
hidden_vector, # Node providing the output of the recurrent layers
target_vector, # Node providing the expected labels (as sparse vectors)
vocab_dim, # Vocabulary size
hidden_dim # Dimension of the hidden vector
):
bias = C.Parameter(shape = (vocab_dim, 1), init = 0)
weights = C.Parameter(shape = (vocab_dim, hidden_dim), init = C.initializer.glorot_uniform())
z = C.reshape(C.times_transpose(weights, hidden_vector) + bias, (1,vocab_dim))
zT = C.times_transpose(z, target_vector)
ce = C.reduce_log_sum_exp(z) - zT
zMax = C.reduce_max(z)
error_on_samples = C.less(zT, zMax)
return (z, ce, error_on_samples)
def triangular_matrix_seq(mode: int = 1):
X = C.placeholder(1)
ones = C.ones_like(X[0])
perm_1 = C.layers.Recurrence(C.plus, return_full_state=True)(ones)
perm_2 = C.layers.Recurrence(C.plus,
go_backwards=True,
return_full_state=True)(ones)
arr_1 = C.sequence.unpack(perm_1, 0, True)
arr_2 = C.sequence.unpack(perm_2, 0, True)
mat = C.times_transpose(arr_1, arr_2)
mat_c = arr_1 * arr_2
diagonal_mat = mat - mat_c
final_mat = diagonal_mat
if mode == 0:
final_mat = C.equal(final_mat, 0)
elif mode == 1:
final_mat = C.less_equal(final_mat, 0)
elif mode == 2:
final_mat = C.less(final_mat, 0)
elif mode == -1:
final_mat = C.greater_equal(final_mat, 0)
elif mode == -2:
final_mat = C.greater(final_mat, 0)
result = C.as_block(final_mat, [(X, X)], 'triangular_matrix')
return C.stop_gradient(result)
def cross_entropy_with_full_softmax(
output, # Node providing the output of the lstm layers
target_vector, # Node providing the expected labels
sv_dim,
vocab_dim
):
sv_vector = output.outputs[3]
z = output.outputs[0]
zT = C.times_transpose(z, target_vector)
# cross entropy loss with softmax function
ce = - C.log(zT)
# the error
zMax = C.reduce_max(z)
error = C.less(zT, zMax)
ce = sequence.reduce_sum(ce)
# discourages the network from turning more than one gate off in a single time step.
sumc = C.abs(C.sequence.slice(sv_vector, 1, 0) - C.sequence.slice(sv_vector, 0, -1))
sumc = sequence.reduce_sum(0.0001 * C.pow(100.0, sumc))
#ce += sumc
# penalise generated utterances that failed to render all the required slots
sumc += C.abs(C.sequence.last(sv_vector))
sumc += C.abs(C.sequence.first(sv_vector) - output.outputs[4])
sumc = C.reduce_sum(sumc)
ce = C.reduce_sum(ce)
ce += sumc
return ce, error
def createDecoderNetwork(self, networkHiddenSrc, srcLength, trgLength):
timeZeroHidden = C.slice(networkHiddenSrc, 0, 0, 1)
srcSentEmb = C.slice(timeZeroHidden, -1, Config.SrcHiddenSize,
Config.SrcHiddenSize * 2)
networkHiddenTrg = {}
inputTrg = C.reshape(self.inputMatrixTrg,
shape=(Config.TrgMaxLength, Config.BatchSize,
Config.TrgVocabSize))
attProbAll = []
tce = 0
for i in range(0, trgLength, 1):
preTrgEmb = self.initTrgEmb if i == 0 else self.EmbTrg(inputTrg[i -
1])
if (i == 0):
networkHiddenTrg[i] = self.createDecoderInitNetwork(srcSentEmb)
else:
(networkHiddenTrg[i], attProb) = self.createDecoderRNNNetwork(
networkHiddenSrc, preTrgEmb, networkHiddenTrg[i - 1],
srcLength)
attProbAll = attProb if i == 1 else C.splice(
attProbAll, attProb, axis=0)
preSoftmax = self.createReadOutNetwork(networkHiddenTrg[i],
preTrgEmb)
ce = C.cross_entropy_with_softmax(preSoftmax, inputTrg[i], 2)
ce = C.reshape(ce, shape=(1, Config.BatchSize))
tce += C.times_transpose(ce, self.maskMatrixTrg[i])
return tce
def attention(query, key, value):
dk = C.reduce_sum(C.ones_like(query)) # cannot use sequence.last, will conflict with recurrence
# dk: [#, *] [1, ] and value = int(dim_of_query)
unpacked_key = C.sequence.unpack(key, padding_value=0, no_mask_output=True) # [#] [-3, key_dim]
unpacked_value = C.sequence.unpack(value, padding_value=0, no_mask_output=True) # [#] [-3, value_dim]
broadcasted_key = C.sequence.broadcast_as(unpacked_key, query) # [#, *] [-3, key_dim]
scaled = C.times_transpose(query, broadcasted_key) / dk
# [#, *] [q_dim] @ [#, *] [key_dim, -3], assert q_dim == key_dim
# scaled: [#, *] [-3, ] => for every key seq element, there is a corresponding score
# masked out invalid temporal connections to obey_sequence_order
if obey_sequence_order and max_seq_len:
unpacked_scaled, scaled_mask = C.sequence.unpack(scaled, padding_value=0).outputs
# unpacked_scaled: [#] [-3, -3] <== matrix will be top right diagonally zero-ed
# scaled_mask: [#] [-3,]
minus_inf = C.constant(-1e+30)
valid_connections = C.Constant(np.tril(np.ones((max_seq_len, max_seq_len)), k=0)) # [] [max_seq, max_seq]
valid_connections = C.reconcile_dynamic_axes(valid_connections, unpacked_scaled) # [#] [max_seq, max_seq]
valid_connections = C.crop_manual(valid_connections, unpacked_scaled, 0, 0) # [#] [-3, -3]
unpacked_scaled = C.element_select(valid_connections, unpacked_scaled, minus_inf) # [#] [-3, -3]
scaled = C.to_sequence_like(unpacked_scaled, query) # [#, *] [-3]
elif obey_sequence_order and not max_seq_len:
raise ValueError("max_seq_len must be defined when obey_sequence_order is True")
attended = C.times(C.softmax(scaled, axis=-1), C.sequence.broadcast_as(unpacked_value, query)) # [#, *] [value_dim,]
return attended
def cross_entropy_with_full_softmax(
hidden_vector, # Node providing the output of the recurrent layers
target_vector, # Node providing the expected labels (as sparse vectors)
vocab_dim, # Vocabulary size
hidden_dim # Dimension of the hidden vector
):
bias = C.Parameter(shape=(vocab_dim, 1), init=0)
weights = C.Parameter(shape=(vocab_dim, hidden_dim),
init=C.initializer.glorot_uniform())
z = C.reshape(
C.times_transpose(weights, hidden_vector) + bias, (1, vocab_dim))
zT = C.times_transpose(z, target_vector)
ce = C.reduce_log_sum_exp(z) - zT
zMax = C.reduce_max(z)
error_on_samples = C.less(zT, zMax)
return (z, ce, error_on_samples)
def model(seq_image, decoded):
params = dense(decoded)
g_x, g_y, sigma2, delta, gamma = attention_parameters(params)
i = C.Constant(np.arange(n) + 1, ) # col of patch
j = C.Constant(np.arange(n) + 1, ) # row of patch
mu_x = g_x + (i - n / 2 - 0.5) * delta
mu_y = g_y + (j - n / 2 - 0.5) * delta
mu_x = C.expand_dims(mu_x, axis=-1)
mu_y = C.expand_dims(mu_y, axis=-1)
# mu_x: [#, *] [n, 1]
# mu_y: [#, *] [n, 1]
image = C.sequence.unpack(seq_image,
padding_value=0,
no_mask_output=True)
# image: [#] [*image_width, filters, image_height]
width_pos = Cx.sequence.position(seq_image)
# width_pos: [#, *] [1]
width_pos_unpacked = C.sequence.unpack(width_pos,
padding_value=999_999,
no_mask_output=True)
# width_pos: [#] [*image_width, 1]
a = C.sequence.broadcast_as(C.swapaxes(width_pos_unpacked), mu_x)
# a: [#, *] [1, *image_width]
# x pos index of image (width)
b = C.Constant(np.arange(image_height).reshape((1, -1)))
# b: [] [1, image_height]
# y pos index of image (height)
# calculate the which portion of the image that is attended by the gaussian filter
f_xi = C.exp(-0.5 * C.square(a - mu_x) / sigma2)
f_yj = C.exp(-0.5 * C.square(b - mu_y) / sigma2)
# f_xi: [#, *] [n, *image_width]
# f_yj: [#, *] [n, image_height]
z_x = C.reduce_sum(f_xi, axis=1)
z_y = C.reduce_sum(f_yj, axis=1)
# z_x: [#, *] [n]
# z_y: [#, *] [n]
f_xi = f_xi / z_x
f_yj = f_yj / z_y
# f_xi: [#, *] [n, *image_width]
# f_yj: [#, *] [n, image_height]
# combine filters from x and y
image_broadcasted = C.sequence.broadcast_as(image, f_yj)
attended = gamma * C.times(
f_xi, C.times_transpose(image_broadcasted, f_yj), output_rank=2)
# attended: [#, *] [n, filters, n]
attended = C.swapaxes(attended)
# attended: [#, *] [filters, n (x) , n (y)]
return attended
def build_trainer(self):
# Set the learning rate, and the momentum parameters for the Adam optimizer.
lr = learning_rate_schedule(self.lr, UnitType.minibatch)
beta1 = momentum_schedule(0.9)
beta2 = momentum_schedule(0.99)
# Calculate the losses.
loss_on_v = cntk.squared_error(self.R, self.v)
pi_a_s = cntk.log(cntk.times_transpose(self.pi, self.action))
loss_on_pi = cntk.variables.Constant(-1) * (cntk.plus(
cntk.times(pi_a_s, cntk.minus(self.R, self.v_calc)),
0.01 * cntk.times_transpose(self.pi, cntk.log(self.pi))))
#loss_on_pi = cntk.times(pi_a_s, cntk.minus(self.R, self.v_calc))
self.tensorboard_v_writer = TensorBoardProgressWriter(
freq=10, log_dir="tensorboard_v_logs", model=self.v)
self.tensorboard_pi_writer = TensorBoardProgressWriter(
freq=10, log_dir="tensorboard_pi_logs", model=self.pi)
# tensorboard --logdir=tensorboard_pi_logs http://localhost:6006/
# tensorboard --logdir=tensorboard_v_logs http://localhost:6006/
# Create the trainiers.
self.trainer_v = cntk.Trainer(self.v, (loss_on_v), [
adam(self.pms_v,
lr,
beta1,
variance_momentum=beta2,
gradient_clipping_threshold_per_sample=2,
l2_regularization_weight=0.01)
], self.tensorboard_v_writer)
self.trainer_pi = cntk.Trainer(self.pi, (loss_on_pi), [
adam(self.pms_pi,
lr,
beta1,
variance_momentum=beta2,
gradient_clipping_threshold_per_sample=2,
l2_regularization_weight=0.01)
], self.tensorboard_pi_writer)
def cross_entropy_with_sampled_softmax(
hidden_vector,
label_vector,
vocab_dim,
hidden_dim,
num_samples,
sampling_weights,
allow_duplicates = False
):
bias = C.layers.Parameter(shape = (vocab_dim, 1), init = 0)
weights = C.layers.Parameter(shape = (vocab_dim, hidden_dim), init = C.initializer.glorot_uniform())
sample_selector_sparse = C.random_sample(sampling_weights, num_samples, allow_duplicates)
sample_selector = sample_selector_sparse
inclusion_probs = C.random_sample_inclusion_frequency(sampling_weights, num_samples, allow_duplicates)
log_prior = C.log(inclusion_probs)
wS = C.times(sample_selector, weights, name='wS')
zS = C.times_transpose(wS, hidden_vector, name='zS1') + C.times(sample_selector, bias, name='zS2') - C.times_transpose (sample_selector, log_prior, name='zS3')
# Getting the weight vector for the true label. Dimension hidden_dim
wT = C.times(label_vector, weights, name='wT')
zT = C.times_transpose(wT, hidden_vector, name='zT1') + C.times(label_vector, bias, name='zT2') - C.times_transpose(label_vector, log_prior, name='zT3')
zSReduced = C.reduce_log_sum_exp(zS)
# Compute the cross entropy that is used for training.
cross_entropy_on_samples = C.log_add_exp(zT, zSReduced) - zT
# For applying the model we also output a node providing the input for the full softmax
z = C.times_transpose(weights, hidden_vector) + bias
z = C.reshape(z, shape = (vocab_dim))
zSMax = C.reduce_max(zS)
error_on_samples = C.less(zT, zSMax)
return (z, cross_entropy_on_samples, error_on_samples)
def test_op_times_sparse_grad(device_id, precision):
dt_precision = PRECISION_TO_TYPE[precision]
from cntk import times, times_transpose, parameter, reshape, Value, sequence
dim = 5
num_sequences = 2
seq = [i for i in range(dim)]
identity = np.identity(dim, dtype=dt_precision)
input_data = Value.one_hot([seq]*num_sequences, dim, dtype=dt_precision)
input_var = sequence.input_variable(shape=(dim), is_sparse=True, needs_gradient=False, dtype=dt_precision)
e = parameter(shape = (dim, dim), init = identity, dtype=dt_precision)
z = reshape(times_transpose(e, times(input_var, e)), dim)
e_grad = z.grad({input_var : input_data}, [e])
assert np.allclose(e_grad, np.ones((dim,dim))*4)
def test_op_times_sparse_grad(device_id, precision):
dt_precision = PRECISION_TO_TYPE[precision]
from cntk import times, times_transpose, parameter, reshape, one_hot
dim = 5
num_sequences = 2
seq = [i for i in range(dim)]
identity = np.identity(dim, dtype=np.float32)
input_data = one_hot([seq] * num_sequences, dim)
input_var = I(shape=(dim), is_sparse=True, needs_gradient=False)
e = parameter(shape=(dim, dim), init=identity)
z = reshape(times_transpose(e, times(input_var, e)), dim)
e_grad = z.grad({input_var: input_data}, [e])
assert np.allclose(e_grad, np.ones((dim, dim)) * 4)
def test_times_transpose_sequence_param(device_id, precision):
dt_precision = PRECISION_TO_TYPE[precision]
from cntk import times_transpose, parameter, sequence, Value
dim = 5
num_sequences = 2
seq = [i for i in range(dim)]
identity = np.identity(dim, dtype=dt_precision)
input_data = Value.one_hot([seq] * num_sequences, dim, dtype=dt_precision)
input_var = sequence.input_variable(shape=(dim),
needs_gradient=True,
dtype=dt_precision)
e = parameter(shape=(dim, ), init=1, dtype=dt_precision)
z = times_transpose(e, input_var)
e_grad = z.grad({input_var: input_data}, [e, input_var])
def dot_attention(self, inputs, memory, dim):
'''
@inputs: [#,c][d] a sequence need attention
@memory(key): [#,q][d] a sequence input refers to compute similarity(weight)
@value: [#,q][d] a sequence input refers to weighted sum
@output: [#,c][d] attention vector
'''
input_ph = C.placeholder()
input_mem = C.placeholder()
with C.layers.default_options(
bias=False,
activation=C.relu): # all the projections have no bias
attn_proj_enc = C.layers.Dense(dim,
init=glorot_uniform(),
input_rank=1,
name="Wqu")
attn_proj_dec = C.layers.Dense(dim,
init=glorot_uniform(),
input_rank=1)
inputs_ = attn_proj_enc(input_ph) # [#,c][d]
memory_ = attn_proj_dec(input_mem) # [#,q][d]
unpack_memory, mem_mask = C.sequence.unpack(
memory_, 0).outputs # [#][*=q, d], [#][*=q]
unpack_memory_expand = C.sequence.broadcast_as(unpack_memory,
inputs_) # [#,c][*=q,d]
matrix = C.times_transpose(inputs_, unpack_memory_expand) / (
dim**0.5) # [#,c][*=q]
mem_mask_expand = C.sequence.broadcast_as(mem_mask,
inputs_) # [#,c][*=q]
matrix = C.element_select(mem_mask_expand, matrix,
C.constant(-1e+30)) # [#,c][*=q]
logits = C.reshape(C.softmax(matrix), (-1, 1)) # [#,c][*=q,1]
# [#,c][*=q, d]
memory_expand = C.sequence.broadcast_as(
C.sequence.unpack(input_mem, 0, no_mask_output=True), input_ph)
weighted_att = C.reshape(C.reduce_sum(logits * memory_expand, axis=0),
(-1, )) # [#,c][d]
return C.as_block(C.combine(weighted_att,
logits), [(input_ph, inputs),
(input_mem, memory)],
'dot attention', 'dot attention')
def hierarchical_softmax_layer(input_var,
label_index,
label_dim,
label_classes=None):
'''
A two layers hierarchical softmax function:
Args:
input_var: Variable with shape: [#,*](dim_x)
label_index: index of label's category: [#,*](1)
label_dim: number of the label categories
label_classes: number of classes of the label categories
Returns:
output_prob: the probability of the given label [#,*](1)
class_probs: the probability of all the label classes [#,*](label_classes)
all_probs: the probability of all label classes
'''
input_dim = input_var.shape[0]
if not label_classes:
label_classes = int(np.ceil(np.sqrt(float(label_dim))))
n_outputs_per_class = int(np.ceil(label_dim / label_classes))
target_class = C.floor((label_index + 0.5) / n_outputs_per_class)
target_output_in_class = C.round(label_index -
target_class * n_outputs_per_class)
w1 = parameter(shape=(input_dim, label_classes),
init=C.glorot_normal(),
name='hsoftmax_w1')
b1 = parameter(shape=(label_classes),
init=C.glorot_normal(),
name='hsoftmax_b1')
w2s = parameter(shape=(
label_classes,
input_dim,
n_outputs_per_class,
),
init=C.glorot_normal(),
name='hsoftmax_w2s')
b2s = parameter(shape=(
label_classes,
n_outputs_per_class,
),
init=C.glorot_normal(),
name='hsoftmax_b2s')
class_probs = softmax(b1 + times(input_var, w1))
# TODO: fix the bug in backprop for sparse, and use sparse embedding to accelerate
target_class_one_hot = C.one_hot(target_class,
num_classes=label_classes,
sparse_output=False)
w2 = C.reshape(C.times(target_class_one_hot, w2s, output_rank=2),
[input_dim, -1])
b2 = C.reshape(times(target_class_one_hot, b2s, output_rank=1), [-1])
probs_in_class = softmax(b2 + times(input_var, w2))
prob_in_class = C.times_transpose(
C.one_hot(target_output_in_class,
num_classes=n_outputs_per_class,
sparse_output=False), probs_in_class)
class_prob = C.times_transpose(
C.one_hot(target_class, num_classes=label_classes,
sparse_output=False), class_probs)
output_prob = prob_in_class * class_prob
# this is for calculating all the outputs' probabilities
all_probs = []
for i in range(label_classes):
ci = C.constant(i)
ci_one_hot = C.one_hot(ci,
num_classes=label_classes,
sparse_output=False)
w2a = C.times(ci_one_hot, w2s, output_rank=2)
b2a = C.times(ci_one_hot, b2s, output_rank=1)
probs_in_classa = C.softmax(b2a + times(input_var, w2a))
class_proba = C.times_transpose(ci_one_hot, class_probs)
output_proba = probs_in_classa * class_proba
all_probs.append(output_proba)
return output_prob, class_probs, all_probs
def self_attention_layer(in_dims: int,
out_dims: int,
name='self_attention',
as_block: bool = False,
k_ph: bool = False,
v_ph: bool = False,
mask_opt: bool = False) -> C.Function:
sq_sa_dims = C.Constant(C.sqrt(out_dims).eval(), name='sq_dims')
X = C.placeholder(
in_dims, (C.Axis.default_batch_axis(), C.Axis.default_dynamic_axis()),
name=name + '_ph')
if k_ph is False and v_ph is False:
q = C.layers.Dense(out_dims, name=name + '_q')(
X
) # W_Q = C.parameter((in_dims, out_dims), init=init, name=name+'_q')
k = C.layers.Dense(out_dims, name=name + '_k')(
X
) # W_K = C.parameter((in_dims, out_dims), init=init, name=name+'_k')
v = C.layers.Dense(out_dims, name=name + '_v')(
X
) # W_V = C.parameter((in_dims, out_dims), init=init, name=name+'_v')
elif k_ph is True and v_ph is True:
q = C.layers.Dense(out_dims, name=name + '_q')(X)
k = C.placeholder(out_dims,
(C.Axis.default_batch_axis(), C.Axis('kv_seq')),
name=name + '_k_ph')
v = C.placeholder(out_dims,
(C.Axis.default_batch_axis(), C.Axis('kv_seq')),
name=name + '_v_ph')
else:
raise Exception(f'k_ph:{k_ph}, v_ph:{v_ph}')
q_ = C.sequence.unpack(q, 0, True, name=name + '_unpack_q')
k_ = C.sequence.unpack(k, 0, True, name=name + '_unpack_k')
v_ = C.sequence.unpack(v, 0, True, name=name + '_unpack_v')
scores = C.times_transpose(q_, k_, name=name + '_score_matrix')
scaled = scores / sq_sa_dims # div_k
if mask_opt:
mask = triangular_matrix_seq(2)(X)
inf_mask = -np.inf * (mask - 0.5)
inf_mask = C.as_block(inf_mask, [(X, X)], 'mask', 'mask')
scaled = C.element_min(scaled, inf_mask)
softmax = C.softmax(scaled, name=name + '_softmax')
attention = C.times(softmax, v_, name=name + '_attention')
result = C.to_sequence_like(attention, X)
if as_block:
if k_ph is False and v_ph is False:
return C.as_block(result, [(X, X)], 'self_attention',
'self_attention_')
elif k_ph is True and v_ph is True:
return C.as_block(result, [(X, X), (k, k), (v, v)],
'self_attention', 'self_attention_')
else:
raise Exception(f'k_ph:{k_ph} v_ph:{v_ph}')
else:
return result
def attention_layer(self, context, query, dim):
input_ph = C.placeholder(shape=(dim, ))
input_mem = C.placeholder(shape=(dim, ))
with C.layers.default_options(bias=False, activation=C.relu):
attn_proj_enc = C.layers.Dense(self.hidden_dim,
init=glorot_uniform(),
input_rank=1,
name="Wqu")
attn_proj_dec = C.layers.Dense(self.hidden_dim,
init=glorot_uniform(),
input_rank=1)
inputs_ = attn_proj_enc(input_ph) # [#,c][d]
memory_ = attn_proj_dec(input_mem) # [#,q][d]
cln_mem_ph = C.placeholder() # [#,q][?=d]
cln_inp_ph = C.placeholder() # [#,c][?=d]
unpack_inputs, inputs_mask = C.sequence.unpack(
cln_inp_ph, 0).outputs # [#][*=c,d] [#][*=c]
expand_inputs = C.sequence.broadcast_as(unpack_inputs,
cln_mem_ph) # [#,q][*=c,d]
matrix = C.reshape(
C.times_transpose(cln_mem_ph, expand_inputs) /
(self.hidden_dim**0.5), (-1, )) # [#,q][*=c]
matrix = C.element_select(
C.sequence.broadcast_as(inputs_mask, cln_mem_ph), matrix,
C.constant(-1e30))
logits = C.softmax(matrix, axis=0, name='level 1 weight') # [#,q][*=c]
trans_expand_inputs = C.transpose(expand_inputs,
[1, 0]) # [#,q][d,*=c]
q_over_c = C.reshape(
C.reduce_sum(logits * trans_expand_inputs, axis=1),
(-1, )) / (self.hidden_dim**0.5) # [#,q][d]
new_q = C.splice(cln_mem_ph, q_over_c) # [#,q][2*d]
# over
unpack_matrix, matrix_mask = C.sequence.unpack(
matrix, 0).outputs # [#][*=q,*=c] [#][*=q]
inputs_mask_s = C.to_sequence(C.reshape(inputs_mask,
(-1, 1))) # [#,c'][1]
trans_matrix = C.to_sequence_like(C.transpose(unpack_matrix, [1, 0]),
inputs_mask_s) # [#,c'][*=q]
trans_matrix = C.sequence.gather(trans_matrix,
inputs_mask_s) # [#,c2][*=q]
trans_matrix = C.element_select(
C.sequence.broadcast_as(matrix_mask, trans_matrix), trans_matrix,
C.constant(-1e30))
logits2 = C.softmax(trans_matrix, axis=0,
name='level 2 weight') # [#,c2][*=c]
unpack_new_q, new_q_mask = C.sequence.unpack(
new_q, 0).outputs # [#][*=q,2*d] [#][*=q]
expand_new_q = C.transpose(
C.sequence.broadcast_as(unpack_new_q, trans_matrix),
[1, 0]) # [#,c2][2d,*=q]
c_over_q = C.reshape(C.reduce_sum(logits2 * expand_new_q, axis=1),
(-1, )) / (2 * self.hidden_dim)**0.5 # [#,c2][2d]
c_over_q = C.reconcile_dynamic_axes(c_over_q, cln_inp_ph)
weighted_q = c_over_q.clone(C.CloneMethod.share, {
cln_mem_ph: memory_,
cln_inp_ph: inputs_
}) # [#,c][2d]
c2c = q_over_c.clone(C.CloneMethod.share, {
cln_mem_ph: inputs_,
cln_inp_ph: inputs_
}) # [#,c][2d]
att_context = C.splice(input_ph, weighted_q, c2c) # 2d+2d+2d
return C.as_block(att_context, [(input_ph, context),
(input_mem, query)], 'attention_layer',
'attention_layer')
def test_times_const_broadcast():
x = C.input_variable((3, ))
a = C.constant(np.ones((3, ), dtype=np.float32))
y = C.times_transpose(a, x)
result = y.eval({x: np.asarray([[1, 2, 3], [1, 2, 3]], dtype=np.float32)})
assert np.array_equal(result, [[6], [6]])
def gpt2_self_attention(token_dims: int,
head_dims: int,
mask_opt: bool = False,
as_block: bool = False,
name: str = 'self_attention'):
X = C.placeholder(token_dims,
dynamic_axes=(C.Axis.default_batch_axis(),
C.Axis.default_dynamic_axis()),
name=name)
# q = C.layers.Dense(token_dims, name=name+'_q')(X)
# k = C.layers.Dense(token_dims, name=name+'_k')(X)
# v = C.layers.Dense(token_dims, name=name+'_v')(X)
# attn_c_attn_w = C.parameter((token_dims,3*token_dims), name='attn_c_attn_w')
# qkv = C.reshape(X@attn_c_attn_w, (3,-1), name='qkv')
qkv = C.layers.Dense((3, token_dims), name='qkv')(X)
q_seq, k_seq, v_seq = qkv[0], qkv[1], qkv[2]
q_mh = C.reshape(q_seq, (head_dims, -1), name='multi_head_q')
k_mh = C.reshape(k_seq, (head_dims, -1), name='multi_head_k')
v_mh = C.reshape(v_seq, (head_dims, -1), name='multi_head_v')
#region split multi head attention
q_heads = [
C.squeeze(q_mh[i], name='simgle_head_q' + str(i))
for i in range(head_dims)
]
k_heads = [
C.squeeze(k_mh[i], name='simgle_head_q' + str(i))
for i in range(head_dims)
]
v_heads = [
C.squeeze(v_mh[i], name='simgle_head_q' + str(i))
for i in range(head_dims)
]
#endregion
attention_head = []
for i in range(head_dims):
q = q_heads[i]
k = k_heads[i]
v = v_heads[i]
#region score
# q_ = C.sequence.last(q, name='last_q'+str(i)) # q present
q_ = C.sequence.unpack(q, 0, True, name='seq_q' + str(i)) # q seq
k_ = C.sequence.unpack(k, 0, True, name='seq_k' + str(i)) # k seq
v_ = C.sequence.unpack(v, 0, True, name='seq_v' + str(i)) # v seq
scores = C.times_transpose(q_, k_)
scaled = scores * (1 / C.sqrt(v_.shape[-1]))
#region mask opt
mask = triangular_matrix_seq(2)(X)
inf_mask = -np.inf * (mask - 0.5)
inf_mask = C.as_block(inf_mask, [(X, X)], 'mask', 'mask')
scaled = C.element_min(scaled, inf_mask)
#endregion
softmax = C.softmax(scaled)
#endregion
#region sum
attention = C.times(softmax, v_)
attention_seq = C.to_sequence_like(attention, X)
#endregion
attention_head.append(attention_seq)
#region merge attention heads
attention = C.splice(*attention_head, name='merged_attention')
#endergion
#region project
project = C.layers.Dense(token_dims, name='project')(attention)
#endregion
if as_block:
return C.as_block(project, [(X, X)], 'gpt2_self_attention',
'gpt2_self_attention')
return project
def gram(x):
features = C.minus(flatten(x), C.reduce_mean(x))
return C.times_transpose(features, features)
def hierarchical_softmax_layer_for_sequence(input_var, num_output_classes, target_class, target_output_in_class, batch_size, w1, b1, w2s, b2s):
'''
A two layers hierarchical softmax function with sequence axis input:
Example:
>>> input_dim = 2
>>> num_output_classes = 4
>>> minibatch_size = 3
>>> seq_size = 5
>>> n_classes = int(math.ceil(math.sqrt(num_output_classes)))
>>> n_outputs_per_class = n_classes
>>> w1 = C.parameter(shape=(input_dim, n_classes), init=C.glorot_normal(seed=2), name='w1')
>>> b1 = C.parameter(shape=(n_classes), init=C.glorot_normal(seed=3), name='b1')
>>> w2s = C.parameter(shape=(n_classes, input_dim, n_outputs_per_class), init=C.glorot_normal(seed=4), name='w2s')
>>> b2s = C.parameter(shape=(n_classes, n_outputs_per_class), init=C.glorot_normal(seed=5), name='b2s')
# neural network structure for hierarchical softmax
>>> h_input = C.sequence.input_variable(input_dim)
>>> h_target_class = C.sequence.input_variable([1])
>>> h_target_output_in_class = C.sequence.input_variable([1])
>>> h_z, class_probs, all_probs = hierarchical_softmax_layer_for_sequence(h_input, num_output_classes, h_target_class, h_target_output_in_class, minibatch_size, w1, b1, w2s, b2s)
>>> a = np.reshape(np.arange(seq_size * minibatch_size * input_dim, dtype = np.float32), (seq_size, minibatch_size, input_dim))
>>> labels = np.reshape(np.arange(seq_size * minibatch_size, dtype = np.float32), (seq_size, minibatch_size, 1)) % num_output_classes
>>> target_labels = labels // n_outputs_per_class
>>> target_output_in_labels = labels % n_outputs_per_class
>>> h_z.eval({h_input: a, h_target_class: target_labels, h_target_output_in_class: target_output_in_labels})[1]
array([[ 0.000859],
[ 0. ],
[ 0. ]], dtype=float32)
Args:
input_var: class:`~cntk.ops.functions.Function` that outputs a tensor with sequence axis and batch axis
num_output_classes: int
target_class: class:`~cntk.ops.functions.Function` that outputs a tensor with sequence axis and batch axis
target_output_in_class: class:`~cntk.ops.functions.Function` that outputs a tensor with sequence axis and batch axis
batch_size: int
w1: C.parameter
b1: C.parameter
w2s: C.parameter
b2s: C.parameter
Returns:
output_prob: class:`~cntk.ops.functions.Function`
class_probs: class:`~cntk.ops.functions.Function`
all_probs: a list of class:`~cntk.ops.functions.Function`
'''
input_dim = input_var.shape[0]
n_classes = int(math.ceil(math.sqrt(num_output_classes)))
n_outputs_per_class = n_classes
class_probs = C.softmax(b1 + C.times(input_var, w1))
w2_temp = C.gather(w2s, target_class)
w2 = reshape(w2_temp, (input_dim, n_outputs_per_class))
w2 = C.sequence.broadcast_as(w2, input_var)
b2 = reshape(C.gather(b2s, target_class), (n_outputs_per_class))
b2 = C.sequence.broadcast_as(b2, input_var)
times_result = times(input_var, w2)
probs_in_class = softmax(b2 + times_result)
probs_in_class = C.sequence.broadcast_as(probs_in_class, target_output_in_class)
target_output_in_class = C.one_hot(target_output_in_class, n_outputs_per_class, False)
probs_in_class = C.sequence.broadcast_as(probs_in_class, target_output_in_class)
prob_in_class = C.times_transpose(probs_in_class, target_output_in_class)
target_class = C.one_hot(target_class, n_classes, False)
class_probs = C.sequence.broadcast_as(class_probs, target_class)
class_prob = C.times_transpose(class_probs, target_class)
output_prob = C.element_times(class_prob, prob_in_class)
# this is for calculating all the outputs' probabilities
all_probs = []
for i in range(n_classes):
ci = C.constant(i)
w2a = C.reshape(C.gather(w2s, ci), (input_dim, n_outputs_per_class))
w2a = C.sequence.broadcast_as(w2a, input_var)
b2a = C.reshape(C.gather(b2s, ci), (n_outputs_per_class))
b2a = C.sequence.broadcast_as(b2a, input_var)
probs_in_classa = C.softmax(b2a + times(input_var, w2a))
cia = C.constant(i, shape=[1])
cia = C.reconcile_dynamic_axes(cia, class_probs)
cia = C.one_hot(cia, n_outputs_per_class, False)
class_proba = C.times_transpose(class_probs, cia)
class_proba = C.sequence.broadcast_as(class_proba, probs_in_classa)
output_proba = C.element_times(class_proba, probs_in_classa)
all_probs.append(output_proba)
return output_prob, class_probs, all_probs
def hierarchical_softmax_layer_for_sequence(input_var, num_output_classes, target_class, target_output_in_class, batch_size, w1, b1, w2s, b2s):
'''
A two layers hierarchical softmax function with sequence axis input:
Example:
>>> input_dim = 2
>>> num_output_classes = 4
>>> minibatch_size = 3
>>> seq_size = 5
>>> n_classes = int(math.ceil(math.sqrt(num_output_classes)))
>>> n_outputs_per_class = n_classes
>>> w1 = C.parameter(shape=(input_dim, n_classes), init=C.glorot_normal(seed=2), name='w1')
>>> b1 = C.parameter(shape=(n_classes), init=C.glorot_normal(seed=3), name='b1')
>>> w2s = C.parameter(shape=(n_classes, input_dim, n_outputs_per_class), init=C.glorot_normal(seed=4), name='w2s')
>>> b2s = C.parameter(shape=(n_classes, n_outputs_per_class), init=C.glorot_normal(seed=5), name='b2s')
# neural network structure for hierarchical softmax
>>> h_input = C.sequence.input_variable(input_dim)
>>> h_target_class = C.sequence.input_variable([1])
>>> h_target_output_in_class = C.sequence.input_variable([1])
>>> h_z, class_probs, all_probs = hierarchical_softmax_layer_for_sequence(h_input, num_output_classes, h_target_class, h_target_output_in_class, minibatch_size, w1, b1, w2s, b2s)
>>> a = np.reshape(np.arange(seq_size * minibatch_size * input_dim, dtype = np.float32), (seq_size, minibatch_size, input_dim))
>>> labels = np.reshape(np.arange(seq_size * minibatch_size, dtype = np.float32), (seq_size, minibatch_size, 1)) % num_output_classes
>>> target_labels = labels // n_outputs_per_class
>>> target_output_in_labels = labels % n_outputs_per_class
>>> h_z.eval({h_input: a, h_target_class: target_labels, h_target_output_in_class: target_output_in_labels})[1]
array([[ 0.000859],
[ 0. ],
[ 0. ]], dtype=float32)
Args:
input_var: class:`~cntk.ops.functions.Function` that outputs a tensor with sequence axis and batch axis
num_output_classes: int
target_class: class:`~cntk.ops.functions.Function` that outputs a tensor with sequence axis and batch axis
target_output_in_class: class:`~cntk.ops.functions.Function` that outputs a tensor with sequence axis and batch axis
batch_size: int
w1: C.parameter
b1: C.parameter
w2s: C.parameter
b2s: C.parameter
Returns:
output_prob: class:`~cntk.ops.functions.Function`
class_probs: class:`~cntk.ops.functions.Function`
all_probs: a list of class:`~cntk.ops.functions.Function`
'''
input_dim = input_var.shape[0]
n_classes = int(math.ceil(math.sqrt(num_output_classes)))
n_outputs_per_class = n_classes
class_probs = C.softmax(b1 + C.times(input_var, w1))
w2_temp = C.gather(w2s, target_class)
w2 = reshape(w2_temp, (input_dim, n_outputs_per_class))
w2 = C.sequence.broadcast_as(w2, input_var)
b2 = reshape(C.gather(b2s, target_class), (n_outputs_per_class))
b2 = C.sequence.broadcast_as(b2, input_var)
times_result = times(input_var, w2)
probs_in_class = softmax(b2 + times_result)
probs_in_class = C.sequence.broadcast_as(probs_in_class, target_output_in_class)
target_output_in_class = C.one_hot(target_output_in_class, n_outputs_per_class, False)
probs_in_class = C.sequence.broadcast_as(probs_in_class, target_output_in_class)
prob_in_class = C.times_transpose(probs_in_class, target_output_in_class)
target_class = C.one_hot(target_class, n_classes, False)
class_probs = C.sequence.broadcast_as(class_probs, target_class)
class_prob = C.times_transpose(class_probs, target_class)
output_prob = C.element_times(class_prob, prob_in_class)
# this is for calculating all the outputs' probabilities
all_probs = []
for i in range(n_classes):
ci = C.constant(i)
w2a = C.reshape(C.gather(w2s, ci), (input_dim, n_outputs_per_class))
w2a = C.sequence.broadcast_as(w2a, input_var)
b2a = C.reshape(C.gather(b2s, ci), (n_outputs_per_class))
b2a = C.sequence.broadcast_as(b2a, input_var)
probs_in_classa = C.softmax(b2a + times(input_var, w2a))
cia = C.constant(i, shape=[1])
cia = C.reconcile_dynamic_axes(cia, class_probs)
cia = C.one_hot(cia, n_outputs_per_class, False)
class_proba = C.times_transpose(class_probs, cia)
class_proba = C.sequence.broadcast_as(class_proba, probs_in_classa)
output_proba = C.element_times(class_proba, probs_in_classa)
all_probs.append(output_proba)
return output_prob, class_probs, all_probs
def test_times_const_broadcast():
x = C.input_variable((3,))
a = C.constant(np.ones((3,), dtype=np.float32))
y = C.times_transpose(a, x)
result = y.eval({x:np.asarray([[1,2,3],[1,2,3]], dtype=np.float32)})
assert np.array_equal(result, [[6], [6]])
