From 819914b6b8db70aa58334204df0a0ff7d889e76f Mon Sep 17 00:00:00 2001
From: choocewhatulike <1901722105@qq.com>
Date: Sat, 10 Mar 2018 17:07:27 +0800
Subject: [PATCH] finish model

---
 model_inplement/code/model.py | 70 +++++++++++++++++++++++++++++++++++
 model_inplement/readme        |  2 +
 2 files changed, 72 insertions(+)
 create mode 100644 model_inplement/code/model.py
 create mode 100644 model_inplement/readme

diff --git a/model_inplement/code/model.py b/model_inplement/code/model.py
new file mode 100644
index 00000000..f73cabe3
--- /dev/null
+++ b/model_inplement/code/model.py
@@ -0,0 +1,70 @@
+import numpy
+
+import torch
+import torch.nn as nn
+from torch.autograd import Variable
+import torch.nn.functional as F
+
+class HAN(nn.Module):
+    def __init__(self, input_size, output_size, 
+                word_hidden_size, word_num_layers, word_context_size, 
+                sent_hidden_size, sent_num_layers, sent_context_size):
+        super(HAN, self).__init__()
+
+        self.word_layer = AttentionNet(input_size, 
+                                    word_hidden_size, 
+                                    word_num_layers, 
+                                    word_context_size)
+        self.sent_layer = AttentionNet(2* word_hidden_size, 
+                                    sent_hidden_size, 
+                                    sent_num_layers, 
+                                    sent_context_size)
+        self.output_layer = nn.Linear(2* sent_hidden_size, output_size)
+        self.softmax = nn.Softmax()
+
+    def forward(self, x, level='w'):
+        # input is a sequence of vector
+        # if level == w, a seq of words (a sent); level == s, a seq of sents (a doc)
+        if level == 's':
+            v = self.sent_layer(x)
+            output = self.softmax(self.output_layer(v))
+            return output
+        elif level == 'w':
+            s = self.word_layer(x)
+            return s
+        else:
+            print('unknow level in Parameter!')
+
+
+class AttentionNet(nn.Module):
+    def __init__(self, input_size, gru_hidden_size, gru_num_layers, context_vec_size):
+        super(AttentionNet, self).__init__()
+        
+        self.input_size = input_size
+        self.gru_hidden_size = gru_hidden_size
+        self.gru_num_layers = gru_num_layers
+        self.context_vec_size = context_vec_size
+
+        # Encoder
+        self.gru = nn.GRU(input_size=input_size, 
+                        hidden_size=gru_hidden_size, 
+                        num_layers=gru_num_layers, 
+                        batch_first=False, 
+                        bidirectional=True)
+        # Attention
+        self.fc = nn.Linear(2* gru_hidden_size, context_vec_size)
+        self.tanh = nn.Tanh()
+        self.softmax = nn.Softmax()
+        # context vector
+        self.context_vec = nn.Parameter(torch.Tensor(context_vec_size, 1))
+        self.context_vec.data.uniform_(-0.1, 0.1)
+
+    def forward(self, inputs):
+        # inputs's dim seq_len*word_dim
+        inputs = torch.unsqueeze(inputs, 1)
+        h_t, hidden = self.gru(inputs)
+        h_t = torch.squeeze(h_t, 1)
+        u = self.tanh(self.fc(h_t))
+        alpha = self.softmax(torch.mm(u, self.context_vec))
+        output = torch.mm(h_t.t(), alpha)
+        return output
diff --git a/model_inplement/readme b/model_inplement/readme
new file mode 100644
index 00000000..9da1bde6
--- /dev/null
+++ b/model_inplement/readme
@@ -0,0 +1,2 @@
+# Implementation of the model in 
+Hierarchical Attention Networks for Document Classification