in NMT/src/model/seq2seq.py [0:0]
def __init__(self, params):
"""
Encoder initialization.
"""
super(Encoder, self).__init__()
# model parameters
self.n_langs = params.n_langs
self.n_words = params.n_words
self.share_lang_emb = params.share_lang_emb
self.emb_dim = params.emb_dim
self.hidden_dim = params.hidden_dim
self.dropout = params.dropout
self.n_enc_layers = params.n_enc_layers
self.enc_dim = params.enc_dim
self.share_enc = params.share_enc
self.proj_mode = params.proj_mode
self.pad_index = params.pad_index
self.freeze_enc_emb = params.freeze_enc_emb
assert not self.share_lang_emb or len(set(params.n_words)) == 1
assert 0 <= self.share_enc <= self.n_enc_layers + int(self.proj_mode == 'proj')
# embedding layers
if self.share_lang_emb:
logger.info("Sharing encoder input embeddings")
layer_0 = nn.Embedding(self.n_words[0], self.emb_dim, padding_idx=self.pad_index)
nn.init.normal_(layer_0.weight, 0, 0.1)
nn.init.constant_(layer_0.weight[self.pad_index], 0)
embeddings = [layer_0 for _ in range(self.n_langs)]
else:
embeddings = []
for n_words in self.n_words:
layer_i = nn.Embedding(n_words, self.emb_dim, padding_idx=self.pad_index)
nn.init.normal_(layer_i.weight, 0, 0.1)
nn.init.constant_(layer_i.weight[self.pad_index], 0)
embeddings.append(layer_i)
self.embeddings = nn.ModuleList(embeddings)
# LSTM layers / shared layers
lstm = [
nn.LSTM(self.emb_dim, self.hidden_dim, num_layers=self.n_enc_layers, dropout=self.dropout)
for _ in range(self.n_langs)
]
for k in range(self.n_enc_layers):
if self.n_enc_layers - k <= self.share_enc - int(self.proj_mode == 'proj'):
logger.info("Sharing encoder LSTM parameters for layer %i" % k)
for i in range(1, self.n_langs):
for name in LSTM_PARAMS:
setattr(lstm[i], name % k, getattr(lstm[0], name % k))
self.lstm = nn.ModuleList(lstm)
# projection layers
if self.proj_mode == 'proj':
if self.share_enc >= 1:
logger.info("Sharing encoder projection layers")
proj_0 = nn.Linear(self.hidden_dim, self.enc_dim)
proj = [proj_0 for _ in range(self.n_langs)]
else:
proj = [nn.Linear(self.hidden_dim, self.enc_dim) for _ in range(self.n_langs)]
self.proj = nn.ModuleList(proj)
else:
self.proj = [None for _ in range(self.n_langs)]