def forward(self, x):
batch_size = x.size()[0]
h_x = x.size()[2]
w_x = x.size()[3]
count_h = self.tensor_size(x[:, :, 1:, :])
count_w = self.tensor_size(x[:, :, :, 1:])
h_tv = flow.pow((x[:, :, 1:, :] - x[:, :, :h_x - 1, :]), 2).sum()
w_tv = flow.pow((x[:, :, :, 1:] - x[:, :, :, :w_x - 1]), 2).sum()
return self.tv_loss_weight * 2 * (h_tv / count_h +
w_tv / count_w) / batch_size
def forward(self, inputs, targets):
"""
Args:
inputs (torch.Tensor): feature matrix with shape (batch_size, feat_dim).
targets (torch.LongTensor): ground truth labels with shape (num_classes).
"""
n = inputs.size(0)
# Compute pairwise distance, replace by the official when merged
dist = flow.pow(inputs, 2).sum(dim=1).expand(n, n)
dist = dist + flow.transpose(dist, dim0=1, dim1=0)
temp1 = -2 * flow.matmul(inputs, flow.transpose(inputs, dim0=1,
dim1=0))
dist = flow.add(dist, temp1)
dist = flow.sqrt(flow.clamp(dist, min=1e-12))
# For each anchor, find the hardest positive and negative
mask = targets.expand(n, n).eq(
flow.transpose(targets.expand(n, n), dim0=1, dim1=0))
dist_ap, dist_an = [], []
y1 = flow.zeros((1, n), dtype=flow.float32).to("cuda")
y2 = flow.Tensor(np.exp(100 * np.ones((1, n)))).to("cuda")
for i in range(n):
temp_dist = flow.slice(dist, [(i, i + 1, 1)])
temp_mask = flow.slice(mask, [(i, i + 1, 1)])
temp_mask_rev = flow.slice(1 - mask, [(i, i + 1, 1)])
dist_ap.append(temp_mask.where(temp_dist, y1).max().unsqueeze(0))
dist_an.append(
temp_mask_rev.where(temp_dist, y2).min().unsqueeze(0))
dist_ap = flow.cat(dist_ap)
dist_an = flow.cat(dist_an)
# Compute ranking hinge loss
y = flow.ones_like(dist_an)
return self.ranking_loss(dist_an, dist_ap, y)
def gelu(x):
"""
Implementation of the GELU activation function currently in Google BERT repo (identical to OpenAI GPT). Also see
the Gaussian Error Linear Units paper: https://arxiv.org/abs/1606.08415
"""
return (0.5 * x * (1.0 + flow.tanh(
math.sqrt(2.0 / math.pi) * (x + 0.044715 * flow.pow(x, 3.0)))))
def _pow(self, b):
return flow.pow(self, b)
def forward(self, x):
return flow.pow(x, 2.0)
def recognize(self, inputs, inputs_mask):
cache = {"fronend": None, "encoder": None, "decoder": None, "lm": None}
self.attn_weights = {}
memory, memory_mask, _, enc_attn_weights = self.encode(
inputs, inputs_mask)
self.attn_weights["encoder"] = enc_attn_weights
self.attn_weights["decoder"] = []
b, t, v = memory.size()
beam_memory = (memory.unsqueeze(1).repeat(
[1, self.beam_width, 1, 1]).view(b * self.beam_width, t, v))
beam_memory_mask = (memory_mask.unsqueeze(1).repeat(
[1, self.beam_width, 1]).view(b * self.beam_width, t))
preds = (flow.ones(
[b * self.beam_width, 1], dtype=flow.int64, device=memory.device) *
BOS)
scores = flow.tensor([0.0] + [-float("inf")] * (self.beam_width - 1),
dtype=flow.float32)
scores = scores.to(memory.device).repeat([b]).unsqueeze(1)
ending_flag = flow.zeros_like(scores).to(dtype=flow.uint8)
with flow.no_grad():
for _ in range(1, self.max_len + 1):
preds, cache, scores, ending_flag = self.decode_step(
preds, beam_memory, beam_memory_mask, cache, scores,
ending_flag)
# whether stop or not
if ending_flag.sum() == b * self.beam_width:
break
scores = scores.view(b, self.beam_width)
preds = preds.view(b, self.beam_width, -1)
lengths = flow.sum(flow.ne(preds, EOS).float(), dim=-1)
# length penalty
if self.penalty:
lp = flow.pow((self.lamda + lengths) / (self.lamda + 1),
self.penalty)
scores /= lp
sorted_scores, offset_indices = flow.sort(scores,
dim=-1,
descending=True)
base_indices = (flow.arange(
b, dtype=flow.int64, device=offset_indices.device) *
self.beam_width)
base_indices = (base_indices.unsqueeze(1).repeat(
[1, self.beam_width]).view(-1))
preds = preds.view(b * self.beam_width, -1)
indices = offset_indices.view(-1) + base_indices
# remove BOS
sorted_preds = preds[indices].view(b, self.beam_width, -1)
nbest_preds = sorted_preds[:, :min(self.beam_width, self.nbest),
1:]
nbest_scores = sorted_scores[:, :min(self.beam_width, self.nbest)]
return self.nbest_translate(nbest_preds), nbest_scores
