Stance-Detection-in-Web-and.../TAN/networks.py
2019-06-18 22:16:04 +05:30

88 lines
2.7 KiB
Python

import torch
import torch.autograd as autograd
import torch.nn as nn
import torch.nn.functional as F
import torch.optim as optim
import numpy as np
import sys
class LSTM_TAN(nn.Module):
def __init__(self,version,embedding_dim, hidden_dim, vocab_size, n_targets,embedding_matrix,dropout = 0.5):
super(LSTM_TAN, self).__init__()
if version not in ["tan-","tan","lstm"]:
print("Version is tan-,tan,lstm")
sys.exit(-1)
self.hidden_dim = hidden_dim
self.embedding_dim = embedding_dim
self.word_embeddings = nn.Embedding(vocab_size, embedding_dim)
self.word_embeddings.weight = nn.Parameter(torch.tensor(embedding_matrix,dtype=torch.float))
self.word_embeddings.weight.requires_grad=True
self.version = version
if version == "tan-":
self.attention = nn.Linear(embedding_dim,1)
elif version == "tan":
self.attention = nn.Linear(2*embedding_dim,1)
self.lstm = nn.LSTM(embedding_dim, hidden_dim, bidirectional=(version!="lstm"))
self.dropout = nn.Dropout(dropout)
if version !="lstm":
self.hidden2target = nn.Linear(2*self.hidden_dim, n_targets)
else:
self.hidden2target = nn.Linear(self.hidden_dim, n_targets)
self.hidden = self.init_hidden()
def init_hidden(self):
return (torch.zeros(1, 1, self.hidden_dim),
torch.zeros(1, 1, self.hidden_dim))
def forward(self, sentence, target,verbose=False):
x_emb = self.word_embeddings(sentence)
version = self.version
if version != "tan-":
t_emb = self.word_embeddings(target)
t_emb = torch.mean(t_emb,dim=0,keepdim=True)
xt_emb = torch.cat((x_emb,t_emb.expand(len(sentence),-1)),dim=1)
if version == "tan-":
lstm_out, _ = self.lstm(
x_emb.view(len(sentence), 1 , self.embedding_dim))
a = self.attention(x_emb)
final_hidden_state = torch.mm(F.softmax(a.view(1,-1),dim=1),lstm_out.view(len(sentence),-1))
elif version == "tan":
a = self.attention(xt_emb)
lstm_out, _ = self.lstm(x_emb.view(len(sentence), 1 , self.embedding_dim))
final_hidden_state = torch.mm(F.softmax(a.view(1,-1),dim=1),lstm_out.view(len(sentence),-1))
elif version == "lstm":
_, hidden_state = self.lstm(
x_emb.view(len(sentence), 1 , self.embedding_dim))
final_hidden_state = hidden_state[0].view(-1,self.hidden_dim)
target_space = self.hidden2target(self.dropout(final_hidden_state))
target_scores = F.log_softmax(target_space, dim=1)
return target_scores