def forward(self, user_id, seq, item_id):
item_embs = np.expand_dims(self.Q(seq), 1)
user_emb = self.P(user_id) # (4096, 10)
out, out_h, out_v, out_hs = None, None, None, []
# 横向卷积
if self.d_prime:
out_v = self.conv_v(item_embs)
out_v = out_v.reshape(
out_v.shape[0], self.fc1_dim_v) # (4096, 4*10)
# 纵向卷积 - 时间
if self.d:
for conv, maxp in zip(self.conv_h, self.max_pool): # 滑动
conv_out = np.squeeze(npx.relu(conv(item_embs)), axis=3)
t = maxp(conv_out)
pool_out = np.squeeze(t, axis=2)
out_hs.append(pool_out)
out_h = np.concatenate(out_hs, axis=1) # (4096, 16*3)
out = np.concatenate([out_v, out_h], axis=1) # (4096, 4*10+16*3)
z = self.fc(self.dropout(out)) # (4096, 10)
# 和user_emb
x = np.concatenate([z, user_emb], axis=1) # (4096, 20)
# 和item_emb计算
q_prime_i = np.squeeze(self.Q_prime(item_id)) # (4096, 20)
b = np.squeeze(self.b(item_id))
res = (x * q_prime_i).sum(1) + b # (4096,)
return res
def incremental_decode(self, step_hidden_states, step_position_embeddings,
past_key_value, mem_states, step_mem_attn_mask):
# 1. self-attention
out = self.self_attn_layer_norm(step_hidden_states)
step_self_query, step_self_key, step_self_value = (
self.transpose_for_scores(self.self_attn_q(out)),
self.transpose_for_scores(self.self_attn_k(out)),
self.transpose_for_scores(self.self_attn_v(out)))
self_key, self_value = (np.concatenate(
[past_key_value[0], step_self_key], axis=self._time_axis),
np.concatenate(
[past_key_value[1], step_self_value],
axis=self._time_axis))
out, _ = self.self_attn(step_self_query, self_key, self_value, None,
step_position_embeddings)
out = self.dropout(self.self_attn_proj(out))
step_hidden_states = step_hidden_states + out
# 2. cross-attention
out = self.cross_attn_layer_norm(step_hidden_states)
step_cross_query, cross_key, cross_value = (
self.transpose_for_scores(self.cross_attn_q(out)),
self.transpose_for_scores(self.cross_attn_k(mem_states)),
self.transpose_for_scores(self.cross_attn_v(mem_states)))
out, _ = self.cross_attn(step_cross_query, cross_key, cross_value,
step_mem_attn_mask)
out = self.dropout(self.cross_attn_proj(out))
step_hidden_states = step_hidden_states + out
# 3. feed forward
step_hidden_states = self.ffn(step_hidden_states)
return step_hidden_states, (self_key, self_value)
def forward(self, positions):
"""
Parameters
----------
positions : NDArray
Shape (..., )
Returns
-------
ret :
Shape (..., units)
"""
emb = np.expand_dims(positions.astype(self._dtype),
axis=-1) * self.base_mult.data()
sin_emb = np.sin(emb)
cos_emb = np.cos(emb)
if self._units % 2 == 0:
return np.concatenate([sin_emb, cos_emb], axis=-1)
else:
return np.concatenate([
sin_emb, cos_emb,
np.expand_dims(np.zeros_like(positions).astype(self._dtype),
axis=-1)
],
axis=-1)
def forward(self,
inputs: np.ndarray,
previous_states: Optional[np.ndarray] = None,
input_lengths: Optional[np.ndarray] = None,
bias: Optional[np.ndarray] = None,
*args) -> Tuple[np.ndarray, np.ndarray]: # mypy: ignore
"""
Computes multi-head attention on a set of inputs, serving as queries, keys, and values.
If sequence lengths are provided, they will be used to mask the attention scores.
A bias mask may also be used to mask the attention scores.
May also use a cache of previously computed inputs.
Returns a ndarray of shape (batch, max_length, output_depth).
:param inputs: Input Data. Shape: (max_length, batch, input_depth).
:param input_lengths: Optional lengths of inputs to mask attention scores. Shape: (batch, 1).
:param bias: Optional 3d bias tensor to mask attention scores.
:param previous_states: Optional list with two ndarrays - previous input's keys and values.
Shape: 2 * (batch, max_length+1, depth_att).
:return: ndarray of shape (batch, max_length, output_depth).
"""
proj = self.ff_in(inputs)
queries, kv_1, kv_2 = np.split(proj, 3, axis=2)
states = np.concatenate((kv_1, kv_2), axis=2)
if previous_states is not None:
states = np.concatenate((previous_states, states), axis=0)
return self._attend(queries, states, lengths=input_lengths,
bias=bias), states
def k_fold_cross_valid(k, epochs, verbose_epoch, X_train, y_train,
learning_rate, weight_decay, batch_size):
"""Conducts k-fold cross validation for the model."""
assert k > 1
fold_size = X_train.shape[0] // k
train_loss_sum = 0.0
test_loss_sum = 0.0
for test_idx in range(k):
X_val_test = X_train[test_idx * fold_size:(test_idx + 1) *
fold_size, :]
y_val_test = y_train[test_idx * fold_size:(test_idx + 1) * fold_size]
val_train_defined = False
for i in range(k):
if i != test_idx:
X_cur_fold = X_train[i * fold_size:(i + 1) * fold_size, :]
y_cur_fold = y_train[i * fold_size:(i + 1) * fold_size]
if not val_train_defined:
X_val_train = X_cur_fold
y_val_train = y_cur_fold
val_train_defined = True
else:
X_val_train = np.concatenate([X_val_train, X_cur_fold],
axis=0)
y_val_train = np.concatenate([y_val_train, y_cur_fold],
axis=0)
net = get_net()
train_loss = train(net, X_val_train, y_val_train, epochs,
verbose_epoch, learning_rate, weight_decay,
batch_size)
train_loss_sum += train_loss
test_loss = get_rmse_log(net, X_val_test, y_val_test)
print("Test loss: %f" % test_loss)
test_loss_sum += test_loss
return train_loss_sum / k, test_loss_sum / k
def get_logits(self, hidden):
"""Get all the logits.
Parameters
----------
F
hidden
The hidden representation
Shape (..., in_units)
Returns
-------
logits
Shape (..., |V|)
"""
if self._cutoffs is None:
if self._in_units != self._embed_size:
hidden = self.inter_proj_l[0](hidden)
logits = self.out_proj_l[0](hidden)
return logits
else:
all_logits = []
if self._div_val == 1.0:
if self._in_units == self._embed_size:
all_scores = self.out_proj_l[0](hidden)
tail_cluster_scores = self.tail_cluster_score_proj(hidden)
else:
inter_hidden = self.inter_proj_l[0](hidden)
all_scores = self.out_proj_l[0](inter_hidden)
tail_cluster_scores = self.tail_cluster_score_proj(
inter_hidden)
all_scores_l = np.split(all_scores, self._cutoffs, axis=-1)
head_scores = all_scores_l[0]
else:
inter_hidden = self.inter_proj_l[0](hidden)
head_scores = self.out_proj_l[0](inter_hidden)
tail_cluster_scores = self.tail_cluster_score_proj(
inter_hidden)
head_tail_cluster_logits = \
npx.log_softmax(np.concatenate([head_scores, tail_cluster_scores],
axis=-1), axis=-1)
head_logits, tail_cluster_logits = \
np.split(head_tail_cluster_logits, [self._cutoffs[0]], axis=-1)
tail_cluster_logits = np.split(tail_cluster_logits,
self._num_tail_clusters,
axis=-1)
all_logits.append(head_logits)
for i in range(1, len(self._cutoffs) + 1):
if self._div_val == 1.0:
ele_scores = all_scores_l[i]
else:
ele_scores = self.out_proj_l[i](
self.inter_proj_l[i](hidden))
ele_logits = npx.log_softmax(ele_scores, axis=-1)
ele_logits = tail_cluster_logits[-i] + ele_logits
all_logits.append(ele_logits)
return np.concatenate(all_logits, axis=-1)
def forward(self, x, layer_states):
"""
Parameters
----------
x
- layout = 'NT'
Shape (batch_size, seq_length, C_in)
- layout = 'TN'
Shape (seq_length, batch_size, C_in)
layer_states
- layout = 'NT'
Shape (2, batch_size, prev_len, C_in)
- layout = 'TN'
Shape (2, prev_len, batch_size, C_in)
"""
x = self.ln(x)
if self._layout == 'NT':
batch_axis, time_axis = 0, 1
prev_len = npx.shape_array(layer_states)[2]
else:
batch_axis, time_axis = 1, 0
prev_len = npx.shape_array(layer_states)[1]
query, key, value = np.split(self.qkv(x), 3, axis=-1)
if layer_states is not None:
prev_key, prev_value = layer_states[0], layer_states[1]
key = np.concatenate([prev_key, key], axis=time_axis)
value = np.concatenate([prev_value, value], axis=time_axis)
new_states = np.stack([key, value], axis=0)
# gen mask
query_pos = npx.arange_like(query, axis=time_axis)
if prev_len is not None:
query_pos = query_pos + prev_len
key_pos = npx.arange_like(key, axis=time_axis)
# (query_len, key_len)
mask = (npx.reshape(key_pos,
(1, -1)) <= npx.reshape(query_pos,
(-1, 1))).astype(
self._dtype)
# broadcast to (batch_size, query_len, key_len)
mask = npx.broadcast_like(np.expand_dims(mask, axis=0),
query,
lhs_axes=0,
rhs_axes=batch_axis)
query = npx.reshape(query, (-2, -2, self._num_heads, -1))
key = npx.reshape(key, (-2, -2, self._num_heads, -1))
value = npx.reshape(value, (-2, -2, self._num_heads, -1))
out, [_, attn_weight] = self.attention_cell(query, key, value, mask)
out = self.out_proj(out)
out = self.hidden_dropout(out)
return out, new_states
def forward(self, user_id, item_id):
p_mf = self.P(user_id)
q_mf = self.Q(item_id)
gmf = p_mf * q_mf
p_mlp = self.U(user_id)
q_mlp = self.V(item_id)
mlp = self.mlp(np.concatenate([p_mlp, q_mlp], axis=1)) # 1024*20
con_res = np.concatenate([gmf, mlp], axis=1)
return np.sum(con_res, axis=-1) # 1024*1
def forward(self, user_id, item_id):
p_mf = self.P(user_id)
# p_mf: (batch_size, num_hidden)
q_mf = self.Q(item_id)
x = p_mf * q_mf
p_mlp = self.U(user_id)
q_mlp = self.V(item_id)
# print(p_mf.shape)
mlp = self.mlp(np.concatenate([p_mlp, q_mlp], axis=1))
con_res = np.concatenate([x, mlp], axis=1)
return self.prediction_layer(con_res)
def get_k_fold_data(k, i, X, y):
assert k > 1
fold_size = X.shape[0] // k
X_train, y_train = None, None
for j in range(k):
idx = slice(j * fold_size, (j + 1) * fold_size)
X_part, y_part = X[idx, :], y[idx]
if j == i:
X_valid, y_valid = X_part, y_part
elif X_train is None:
X_train, y_train = X_part, y_part
else:
X_train = np.concatenate([X_train, X_part], 0)
y_train = np.concatenate([y_train, y_part], 0)
return X_train, y_train, X_valid, y_valid
def forward(self, V_A, V_B):
# Sum up both sets of comparison vectors
V_A = V_A.sum(axis=1)
V_B = V_B.sum(axis=1)
# Feed the concatenation of both summarization results into an MLP
Y_hat = self.h(np.concatenate([V_A, V_B], axis=1))
return Y_hat
def get_answerable_logits(self, contextual_embedding, p_mask):
"""Get the answerable logits.
Parameters
----------
contextual_embedding
Shape (batch_size, sequence_length, C)
p_mask
Shape (batch_size, sequence_length)
Mask the sequence.
0 --> Denote that the element is masked,
1 --> Denote that the element is not masked
Returns
-------
answerable_logits
Shape (batch_size, 2)
"""
# Shape (batch_size, sequence_length)
start_scores = np.squeeze(self.start_scores(contextual_embedding), -1)
start_score_weights = masked_softmax(start_scores, p_mask, axis=-1)
start_agg_feature = npx.batch_dot(np.expand_dims(start_score_weights, axis=1),
contextual_embedding)
start_agg_feature = np.squeeze(start_agg_feature, 1)
cls_feature = contextual_embedding[:, 0, :]
answerable_scores = self.answerable_scores(np.concatenate([start_agg_feature,
cls_feature], axis=-1))
answerable_logits = npx.log_softmax(answerable_scores, axis=-1)
return answerable_logits
def train_s2s(model: gluon.nn.Block, data_iter, lr, num_epochs, tgt_vocab,
device):
trainer = gluon.Trainer(model.collect_params(), 'adam',
{'learning_rate': lr})
loss = MaskedSoftmaxCELoss()
animator = d2l.Animator(xlabel='epocs',
ylabel='loss',
xlim=[10, num_epochs])
for epoch in range(num_epochs):
timer = d2l.Timer()
metric = d2l.Accumulator(2)
for batch in data_iter:
X, X_valid_len, Y, Y_valid_len = [
x.as_in_ctx(device) for x in batch
]
bos_id = tgt_vocab['<bos>']
bos = np.array([bos_id] * Y.shape[0], ctx=device)
bos = bos.reshape(-1, 1)
dec_input = np.concatenate(
[bos, Y[:, :-1]], axis=1) # Teacher forcing # bos+Y(除了最后一个字符)
with autograd.record():
Y_hat, _ = model(X, dec_input)
l = loss(Y_hat, Y, Y_valid_len)
l.backward()
d2l.grad_clipping(model, 1)
num_tokens = Y_valid_len.sum()
trainer.step(num_tokens)
metric.add(l.sum(), num_tokens)
if (epoch + 1) % 10 == 0:
animator.add(epoch + 1, (metric[0] / metric[1], ))
print(f'loss {metric[0] / metric[1]:.3f}, {metric[1] / timer.stop():.1f} '
f'tokens/sec on {str(device)}')
def get_end_logits(self, contextual_embedding, start_positions, p_mask):
"""
Parameters
----------
contextual_embedding
Shape (batch_size, sequence_length, C)
start_positions
Shape (batch_size, N)
We process multiple candidates simultaneously
p_mask
Shape (batch_size, sequence_length)
Returns
-------
end_logits
Shape (batch_size, N, sequence_length)
"""
# Select the features at the start_positions
# start_feature will have shape (batch_size, N, C)
start_features = select_vectors_by_position(contextual_embedding, start_positions)
# Concatenate the start_feature and the contextual_embedding
contextual_embedding = np.expand_dims(contextual_embedding, axis=1) # (B, 1, T, C)
start_features = np.expand_dims(start_features, axis=2) # (B, N, 1, C)
concat_features = np.concatenate([npx.broadcast_like(start_features,
contextual_embedding, 2, 2),
npx.broadcast_like(contextual_embedding,
start_features, 1, 1)],
axis=-1) # (B, N, T, 2C)
end_scores = self.end_scores(concat_features)
end_scores = np.squeeze(end_scores, -1)
end_logits = masked_logsoftmax(end_scores, mask=np.expand_dims(p_mask, axis=1),
axis=-1)
return end_logits
def _get_vocab_slice_ids(restrict_lexicon: Optional[lexicon.TopKLexicon],
source_words: np.ndarray,
raw_constraint_list: List[Optional[constrained.RawConstraintList]],
eos_id: int,
beam_size: int) -> Tuple[np.ndarray, int, List[Optional[constrained.RawConstraintList]]]:
vocab_slice_ids = np.array(restrict_lexicon.get_trg_ids(source_words.astype("int32", copy=False).asnumpy()), dtype='int32')
ctx = source_words.ctx
if any(raw_constraint_list):
# Add the constraint IDs to the list of permissibled IDs, and then project them into the reduced space
constraint_ids = np.array(word_id for sent in raw_constraint_list for phr in sent for word_id in phr)
vocab_slice_ids = onp.lib.arraysetops.union1d(vocab_slice_ids, constraint_ids) # type: ignore
full_to_reduced = dict((val, i) for i, val in enumerate(vocab_slice_ids))
raw_constraint_list = [[[full_to_reduced[x] for x in phr] for phr in sent] for sent in
raw_constraint_list]
# pad to a multiple of 8.
vocab_slice_ids = np.pad(vocab_slice_ids, (0, 7 - ((len(vocab_slice_ids) - 1) % 8)),
mode='constant', constant_values=eos_id)
vocab_slice_ids_shape = vocab_slice_ids.shape[0]
if vocab_slice_ids_shape < beam_size + 1:
# This fixes an edge case for toy models, where the number of vocab ids from the lexicon is
# smaller than the beam size.
logger.warning("Padding vocab_slice_ids (%d) with EOS to have at least %d+1 elements to expand",
vocab_slice_ids_shape, beam_size)
n = beam_size - vocab_slice_ids_shape + 1
vocab_slice_ids = np.concatenate((vocab_slice_ids, np.full((n,), fill_value=eos_id, ctx=ctx, dtype='int32')),
axis=0)
logger.debug(f'decoder softmax size: {vocab_slice_ids_shape}')
return vocab_slice_ids, vocab_slice_ids_shape, raw_constraint_list
def forward(self, best_hyp_indices, best_word_indices,
finished, scores_accumulated, lengths, reference_lengths,
factors=None):
# Reorder fixed-size beam data according to best_hyp_indices (ascending)
finished = np.take(finished, best_hyp_indices, axis=0)
lengths = np.take(lengths, best_hyp_indices, axis=0)
reference_lengths = np.take(reference_lengths, best_hyp_indices, axis=0)
# Normalize hypotheses that JUST finished
all_finished = np.expand_dims(np.logical_or(best_word_indices == self.pad_id,
best_word_indices == self.eos_id),
axis=1)
newly_finished = np.logical_xor(all_finished, finished)
scores_accumulated = np.where(newly_finished,
self._scorer(scores_accumulated,
npx.cast(lengths, self.dtype),
reference_lengths),
scores_accumulated)
# Recompute finished. Hypotheses are finished if they are extended with <pad> or <eos>
finished = np.logical_or(best_word_indices == self.pad_id, best_word_indices == self.eos_id)
finished = npx.cast(np.expand_dims(finished, axis=1), 'int32')
# Concatenate sorted secondary target factors to best_word_indices. Shape: (batch*beam, num_factors)
best_word_indices = np.expand_dims(best_word_indices, axis=1)
if factors is not None:
secondary_factors = np.take(factors, best_hyp_indices, axis=0)
best_word_indices = np.concatenate((best_word_indices, secondary_factors), axis=1)
return best_word_indices, finished, scores_accumulated, lengths, reference_lengths
def forward(self, target_dists, finished, inactive,
scores_accumulated, lengths, max_lengths,
unk_dist, pad_dist, eos_dist):
# make sure to avoid generating <unk> if unk_dist is specified
if unk_dist is not None:
target_dists = target_dists + unk_dist
# broadcast hypothesis score to each prediction.
# scores_accumulated. Shape: (batch*beam, 1)
# target_dists. Shape: (batch*beam, vocab_size)
scores = target_dists + scores_accumulated
# Special treatment for finished and inactive rows. Inactive rows are inf everywhere;
# finished rows are inf everywhere except column zero (pad_id), which holds the accumulated model score.
# Items that are finished (but not inactive) get their previous accumulated score for the <pad> symbol,
# infinity otherwise.
# pad_dist. Shape: (batch*beam, vocab_size)
pad_dist = np.concatenate((scores_accumulated, pad_dist), axis=1)
scores = np.where(np.logical_or(finished, inactive), pad_dist, scores)
# Update lengths of all items, except those that were already finished. This updates
# the lengths for inactive items, too, but that doesn't matter since they are ignored anyway.
lengths = lengths + (1 - finished)
# Items that are at their maximum length and not finished now are forced to produce the <eos> symbol.
# That is, we keep scores for hypotheses below max length or finished, and 'force-eos' the rest.
below_max_length = lengths < max_lengths
scores = np.where(np.logical_or(below_max_length, finished), scores, eos_dist + scores)
return scores, lengths
def decode_step(self,
step_input: np.ndarray,
states: List[np.ndarray],
vocab_slice_ids: Optional[np.ndarray] = None):
outputs = [] # type: List[np.ndarray]
new_states = [] # type: List[np.ndarray]
factor_outputs = [] # type: List[List[np.ndarray]]
state_index = 0
for model, model_state_structure in zip(self._models, self.state_structure()):
model_states = states[state_index:state_index+len(model_state_structure)]
state_index += len(model_state_structure)
logits, model_states, target_factor_outputs = model.decode_step(step_input, model_states, vocab_slice_ids)
probs = npx.softmax(logits, axis=-1, temperature=self._softmax_temperature)
outputs.append(probs)
target_factor_probs = [npx.softmax(tfo, axis=-1) for tfo in target_factor_outputs]
factor_outputs.append(target_factor_probs)
new_states += model_states
scores = self._interpolation(outputs)
target_factors = None # type: Optional[np.ndarray]
if factor_outputs:
# target factors are greedily 'decoded'.
factor_predictions = [npx.cast(np.expand_dims(np.argmin(self._interpolation(fs), axis=-1), axis=1), dtype='int32')
for fs in zip(*factor_outputs)]
if factor_predictions:
target_factors = factor_predictions[0] if len(factor_predictions) == 1 \
else np.concatenate(factor_predictions, axis=1)
return scores, new_states, target_factors
def forward(self,x):
p1 = self.p1_1(x)
p2 = self.p2_2(self.p2_1(x))
p3 = self.p3_1(self.p3_1(x))
p4 = self.p4_2(self.p4_1(x))
return np.concatenate((p1,p2,p3,p4), axis=1)
def rnn(inputs, hidden_states, params):
'''
inputs shape: (num_steps[seq-len],batch_size,vocab_size)
return:
outputs,(H,)
'''
W_xh, W_hh, b_h, W_ho, b_o = params
H, = hidden_states
outputs = []
hidden_states = []
# X shape: (batch_size,vocab_size)
print(
f"rnn loops {inputs.shape[0]} times along seq_length axis---------\n")
i = 1
for X in inputs: # 沿着num_steps(sequence length)循环
print(f"loops {i} times \n")
i += 1
H = mxnp.dot(X, W_xh) + mxnp.dot(H, W_hh) + b_h
H = mxnp.tanh(H)
hidden_states.append(H)
print(
f"---rnn input(X,H) and weights' shape---------\n"
f" ---X.shape={X.shape},W_xh.shape={W_xh.shape}\n"
f" ---H.shape={H.shape},W_hh.shape={W_hh.shape},b_h.shape={b_h.shape}\n"
f" ---W_ho.shape={W_ho.shape},b_o.shape={b_o.shape}\n")
Y = mxnp.dot(H, W_ho) + b_o
outputs.append(Y)
print(f"---rnn output's shape---------\n"
f" ---Y.shape={Y.shape},H.shape={H.shape}\n")
Ys = mxnp.concatenate(outputs, axis=0)
print(f"Final Ys.shape={Ys.shape}")
return Ys, (H, ), hidden_states, outputs
def offset_inverse(anchors, offset_preds):
c_anc = d2l.box_corner_to_center(anchors)
c_pred_bb_xy = (offset_preds[:, :2] * anchors[:, 2:]) / 10 + c_anc[:, :2]
c_pred_bb_wh = np.exp(offset_preds[:, 2:] / 5) * c_anc[:, 2:]
c_pred_bb = np.concatenate((c_pred_bb_xy, c_pred_bb_wh), axis=1)
predicted_bb = d2l.box_center_to_corner(c_pred_bb)
return predicted_bb
def forward(self, _layer_lo, _layer_hi):
up = self.up(_layer_lo)
up = FFx.relu(up)
x = FF.concatenate([up, _layer_hi], axis=1)
x = self.conv_normed(x)
return x
def forward(self, x, y):
x = self.upconv(x)
# x = self.upBN(x)
x = np.concatenate([x, y], axis=1)
x = self.conv1(x)
x = self.conv2(x)
x = self.conv3(x)
return x
def multibox_prior(data, sizes, ratios):
#data: batch, channels, height, width
in_height, in_width = data.shape[-2:]
device, num_sizes, num_ratios = data.ctx, len(sizes), len(ratios)
boxes_per_pixel = num_sizes + num_ratios - 1
size_tensor = np.array(sizes, ctx=device)
ratio_tensor = np.array(ratios, ctx=device)
# Offsets are required to move the anchor to center of a pixel
# Since pixel (height=1, width=1), we choose to offset our centers by 0.5
offset_w, offset_h = 0.5, 0.5
steps_h = 1.0 / in_height # Scaled steps in y axis
steps_w = 1.0 / in_width # Scaled steps in x axis
# Generate all center points for the anchor boxes
center_h = (np.arange(in_height, ctx=device) + offset_h) * steps_h
center_w = (np.arange(in_width, ctx=device) + offset_w) * steps_w
shift_x, shift_y = np.meshgrid(center_w, center_h)
shift_x, shift_y = shift_x.reshape(-1), shift_y.reshape(-1)
# Generate boxes_per_pixel number of heights and widths which are later
# used to create anchor box corner coordinates (xmin, xmax, ymin, ymax)
# concat (various sizes, first ratio) and (first size, various ratios)
w = np.concatenate((size_tensor * np.sqrt(ratio_tensor[0]),
size_tensor[0]* np.sqrt(ratio_tensor[1:])))\
* in_height / in_width
h = np.concatenate((size_tensor / np.sqrt(ratio_tensor[0]),
sizes[0] / np.sqrt(ratio_tensor[1:])))
# Divide by 2 to get half height and half width
anchor_manipulations = np.tile(
np.stack((-w, -h, w, h)).T, (in_height * in_width, 1)) / 2
# Each center point will have boxes_per_pixel number of anchor boxes, so
# generate grid of all anchor box centers with boxes_per_pixel repeats
out_grid = np.stack([shift_x, shift_y, shift_x, shift_y],
axis=1).repeat(boxes_per_pixel, axis=0)
output = out_grid + anchor_manipulations
# print(output)
print(in_height, in_width)
return np.expand_dims(output, axis=0)
def forward(self, X, state):
enc_outputs, hidden_state, enc_valid_len = state
X = self.embedding(X).swapaxes(0, 1)
outputs = []
for x in X:
# query shape: (batch_size, 1, num_hiddens)
query = np.expand_dims(hidden_state[0][-1], axis=1)
# context has same shape as query
context = self.attention_cell(query, enc_outputs, enc_outputs,
enc_valid_len)
# Concatenate on the feature dimension
x = np.concatenate((context, np.expand_dims(x, axis=1)), axis=-1)
# Reshape x to (1, batch_size, embed_size + num_hiddens)
out, hidden_state = self.rnn(x.swapaxes(0, 1), hidden_state)
outputs.append(out)
outputs = self.dense(np.concatenate(outputs, axis=0))
return outputs.swapaxes(0,
1), [enc_outputs, hidden_state, enc_valid_len]
def n_dim_array_operations():
x = np.array([1, 2, 4, 8])
y = np.array([2, 2, 2, 2])
print(x + y, x - y, x * y, x / y,
x**y) # The ** operator is exponentiation
print("e^x of {} = {}".format(x, np.exp(x)))
print("sin(x) of {} = {}".format(x, np.sin(x)))
x = np.arange(12).reshape(3, 4)
y = np.array([[2, 1, 4, 3], [1, 2, 3, 4], [4, 3, 2, 1]])
axis0 = np.concatenate([x, y], axis=0)
print("concat axis 0 : {}, shape {}".format(axis0, axis0.shape))
axis1 = np.concatenate([x, y], axis=1)
print("concat axis 1 : {}, shape {}".format(axis1, axis1.shape))
equal = x == y
greater = x > y
print("equal x = y: {} == {} = {}".format(x, y, equal))
print("greater x > y: {} > {} = {}".format(x, y, greater))
def batch_check(x1, x2, axises, shapes):
for a, s in zip(axises, shapes):
x1.attach_grad()
with mx.autograd.record():
y = np.concatenate((x1, x2), axis=a)
assert y.shape == s
y.backward()
assert x1.grad.shape == (2, INT_OVERFLOW)
assert x1.grad[0][0] == 1
def offset_boxes(anchors, assigned_bb, eps=1e-6):
c_anc = d2l.box_corner_to_center(anchors)
c_assigned_bb = d2l.box_corner_to_center(assigned_bb)
offset_xy = 10 * (c_assigned_bb[:, :2] -
c_anc[:, :2]) / c_anc[:, 2:] # standard deviation = 0.1
offset_wh = 5 * np.log(
eps + c_assigned_bb[:, 2:] / c_anc[:, 2:]) # standard deviation = 0.2
offset = np.concatenate([offset_xy, offset_wh], axis=1)
print(offset.shape, 'das')
return offset
def forward(self, inputs):
# Concatenate the output of two embedding layers with shape of
# (batch size, no. of words, word vector dimension) by word vector
embeddings = np.concatenate((
self.embedding(inputs), self.constant_embedding(inputs)), axis=2)
# According to the input format required by Conv1D, the word vector
# dimension, that is, the channel dimension of the one-dimensional
# convolutional layer, is transformed into the previous dimension
embeddings = embeddings.transpose(0, 2, 1)
# For each one-dimensional convolutional layer, after max-over-time
# pooling, an ndarray with the shape of (batch size, channel size, 1)
# can be obtained. Use the flatten function to remove the last
# dimension and then concatenate on the channel dimension
encoding = np.concatenate([
np.squeeze(self.pool(conv(embeddings)), axis=-1)
for conv in self.convs], axis=1)
# After applying the dropout method, use a fully connected layer to
# obtain the output
outputs = self.decoder(self.dropout(encoding))
return outputs
def forward(self, input1, input2):
out = mx.contrib.nd.BilinearResize2D(input1.as_nd_ndarray(),
scale_height=2.,
scale_width=2.)
out = out.as_np_ndarray()
out = self.conv1(out)
out = FFx.relu(out)
out2 = self.conv2(FF.concatenate([out, input2], axis=1))
out2 = FFx.relu(out2)
return out2