File size: 5,180 Bytes
85ec4af
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Rhizome
# Version beta 0.0, August 2023
# Property of IBM Research, Accelerated Discovery
#

"""
PLEASE NOTE THIS IMPLEMENTATION INCLUDES THE ORIGINAL SOURCE CODE (AND SOME ADAPTATIONS)
OF THE MHG IMPLEMENTATION OF HIROSHI KAJINO AT IBM TRL ALREADY PUBLICLY AVAILABLE. 
THIS MIGHT INFLUENCE THE DECISION OF THE FINAL LICENSE SO CAREFUL CHECK NEEDS BE DONE. 
"""

""" Title """

__author__ = "Hiroshi Kajino <[email protected]>"
__copyright__ = "(c) Copyright IBM Corp. 2018"
__version__ = "0.1"
__date__ = "Aug 9 2018"


import abc
import numpy as np
import torch
from torch import nn


class DecoderBase(nn.Module):

    def __init__(self):
        super().__init__()
        self.hidden_dict = {}

    @abc.abstractmethod
    def forward_one_step(self, tgt_emb_in):
        ''' one-step forward model

        Parameters
        ----------
        tgt_emb_in : Tensor, shape (batch_size, input_dim)

        Returns
        -------
        Tensor, shape (batch_size, hidden_dim)
        '''
        tgt_emb_out = None
        return tgt_emb_out

    @abc.abstractmethod
    def init_hidden(self):
        ''' initialize the hidden states
        '''
        pass

    @abc.abstractmethod
    def feed_hidden(self, hidden_dict_0):
        for each_hidden in self.hidden_dict.keys():
            self.hidden_dict[each_hidden][0] = hidden_dict_0[each_hidden]


class GRUDecoder(DecoderBase):

    def __init__(self, input_dim: int, hidden_dim: int, num_layers: int,
                 dropout: float, batch_size: int, use_gpu: bool,
                 no_dropout=False):
        super().__init__()
        self.input_dim = input_dim
        self.hidden_dim = hidden_dim
        self.num_layers = num_layers
        self.dropout = dropout
        self.batch_size = batch_size
        self.use_gpu = use_gpu
        self.model = nn.GRU(input_size=self.input_dim,
                            hidden_size=self.hidden_dim,
                            num_layers=self.num_layers,
                            batch_first=True,
                            bidirectional=False,
                            dropout=self.dropout if not no_dropout else 0
        )
        if self.use_gpu:
            self.model.cuda()
        self.init_hidden()

    def init_hidden(self):
        self.hidden_dict['h'] = torch.zeros((self.num_layers,
                                             self.batch_size,
                                             self.hidden_dim),
                                            requires_grad=False)
        if self.use_gpu:
            self.hidden_dict['h'] = self.hidden_dict['h'].cuda()

    def forward_one_step(self, tgt_emb_in):
        ''' one-step forward model

        Parameters
        ----------
        tgt_emb_in : Tensor, shape (batch_size, input_dim)

        Returns
        -------
        Tensor, shape (batch_size, hidden_dim)
        '''
        tgt_emb_out, self.hidden_dict['h'] \
            = self.model(tgt_emb_in.view(self.batch_size, 1, -1),
                         self.hidden_dict['h'])
        return tgt_emb_out


class LSTMDecoder(DecoderBase):

    def __init__(self, input_dim: int, hidden_dim: int, num_layers: int,
                 dropout: float, batch_size: int, use_gpu: bool,
                 no_dropout=False):
        super().__init__()
        self.input_dim = input_dim
        self.hidden_dim = hidden_dim
        self.num_layers = num_layers
        self.dropout = dropout
        self.batch_size = batch_size
        self.use_gpu = use_gpu
        self.model = nn.LSTM(input_size=self.input_dim,
                             hidden_size=self.hidden_dim,
                             num_layers=self.num_layers,
                             batch_first=True,
                             bidirectional=False,
                             dropout=self.dropout if not no_dropout else 0)
        if self.use_gpu:
            self.model.cuda()
        self.init_hidden()

    def init_hidden(self):
        self.hidden_dict['h'] = torch.zeros((self.num_layers,
                                             self.batch_size,
                                             self.hidden_dim),
                                            requires_grad=False)
        self.hidden_dict['c'] = torch.zeros((self.num_layers,
                                             self.batch_size,
                                             self.hidden_dim),
                                            requires_grad=False)
        if self.use_gpu:
            for each_hidden in self.hidden_dict.keys():
                self.hidden_dict[each_hidden] = self.hidden_dict[each_hidden].cuda()

    def forward_one_step(self, tgt_emb_in):
        ''' one-step forward model

        Parameters
        ----------
        tgt_emb_in : Tensor, shape (batch_size, input_dim)

        Returns
        -------
        Tensor, shape (batch_size, hidden_dim)
        '''
        tgt_hidden_out, self.hidden_dict['h'], self.hidden_dict['c'] \
            = self.model(tgt_emb_in.view(self.batch_size, 1, -1),
                         self.hidden_dict['h'], self.hidden_dict['c'])
        return tgt_hidden_out