File size: 11,846 Bytes
2d06dcc
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
import torch
import torch.nn.functional as F
import numpy as np
import logging
import os
import time 

from torch.utils.data import DataLoader, TensorDataset, RandomSampler
from sklearn.cluster import KMeans
from sklearn.metrics import confusion_matrix
from tqdm import trange, tqdm
from scipy.optimize import linear_sum_assignment
from losses import loss_map
from utils.functions import save_model, restore_model
from transformers import BertTokenizer

from utils.metrics import clustering_score
from utils.functions import set_seed, view_generator
from losses import loss_map
from .pretrain import PretrainUnsupUSNIDManager

class UnsupUSNIDManager:
    
    def __init__(self, args, data, model, logger_name = 'Discovery'):

        pretrain_manager = PretrainUnsupUSNIDManager(args, data, model)
    
        set_seed(args.seed)
        self.logger = logging.getLogger(logger_name)

        loader = data.dataloader
        self.train_dataloader, self.test_dataloader = \
            loader.train_outputs['loader'], loader.test_outputs['loader']

        self.train_outputs = loader.train_outputs
        self.criterion = loss_map['CrossEntropyLoss']
        self.contrast_criterion = loss_map['SupConLoss']
        self.tokenizer = BertTokenizer.from_pretrained(args.pretrained_bert_model, do_lower_case=True)    
        self.generator = view_generator(self.tokenizer, args)
        
        if args.pretrain:
            self.pretrained_model = pretrain_manager.model
            
            self.set_model_optimizer(args, data, model, pretrain_manager)
            self.load_pretrained_model(args, self.pretrained_model)
            
        else:
            self.pretrained_model = restore_model(pretrain_manager.model, os.path.join(args.method_output_dir, 'pretrain'))   
            self.set_model_optimizer(args, data, model, pretrain_manager)
            
            if args.train:
                self.load_pretrained_model(args, self.pretrained_model)
            else:
                self.model = restore_model(self.model, args.model_output_dir)   
    
    def set_model_optimizer(self, args, data, model, pretrain_manager):
        
        args.num_labels = self.num_labels = data.num_labels
        self.model = model.set_model(args, data, 'bert', args.freeze_train_bert_parameters)     
        self.optimizer , self.scheduler = model.set_optimizer(self.model, data.dataloader.num_train_examples, args.train_batch_size, \
            args.num_train_epochs, args.lr, args.warmup_proportion)
        
        self.device = model.device
    
    def clustering(self, args, init = 'k-means++'):
        
        outputs = self.get_outputs(args, mode = 'train', model = self.model)
        feats = outputs['feats']
        y_true = outputs['y_true']
        
        if init == 'k-means++':
            
            self.logger.info('Initializing centroids with K-means++...')
            start = time.time()
            km = KMeans(n_clusters = self.num_labels, n_jobs = -1, random_state=args.seed, init = 'k-means++').fit(feats) 
            
            km_centroids, assign_labels = km.cluster_centers_, km.labels_
            end = time.time()
            self.logger.info('K-means++ used %s s', round(end - start, 2))   
            
        elif init == 'centers':
            
            start = time.time()
            km = KMeans(n_clusters = self.num_labels, n_jobs = -1, random_state=args.seed, init = self.centroids).fit(feats)
            km_centroids, assign_labels = km.cluster_centers_, km.labels_ 
            end = time.time()
            self.logger.info('K-means used %s s', round(end - start, 2))

        self.centroids = km_centroids
        pseudo_labels = torch.tensor(assign_labels, dtype=torch.long)      
        
        return outputs, km_centroids, y_true, assign_labels, pseudo_labels
                      
    def train(self, args, data): 

        self.centroids = None
        last_preds = None
        
        for epoch in trange(int(args.num_train_epochs), desc="Epoch"):  
            
            init_mechanism = 'k-means++' if epoch == 0 else 'centers'
            
            outputs, km_centroids, y_true, assign_labels, pseudo_labels = self.clustering(args, init = init_mechanism)

            current_preds = pseudo_labels.numpy()
            delta_label = np.sum(current_preds != last_preds).astype(np.float32) / current_preds.shape[0] 
            last_preds = np.copy(current_preds)
            
            if epoch > 0:
                
                self.logger.info("***** Epoch: %s *****", str(epoch))
                self.logger.info('Training Loss: %f', np.round(tr_loss, 5))
                self.logger.info('Delta Label: %f', delta_label)
                
                if delta_label < args.tol:
                    self.logger.info('delta_label %s < %f', delta_label, args.tol)  
                    self.logger.info('Reached tolerance threshold. Stop training.')
                    break                   
            
            self.train_outputs['label_ids'] = pseudo_labels

            pseudo_train_dataloader = self.get_augment_dataloader(args, self.train_outputs, pseudo_labels)

            tr_loss = 0
            nb_tr_examples, nb_tr_steps = 0, 0
            self.model.train()

            for batch in tqdm(pseudo_train_dataloader, desc="Training(All)"):
                
                batch = tuple(t.to(self.device) for t in batch)
                input_ids, input_mask, segment_ids, label_ids = batch

                with torch.set_grad_enabled(True):

                    input_ids_a, input_ids_b = self.batch_chunk(input_ids)
                    input_mask_a, input_mask_b = self.batch_chunk(input_mask)
                    segment_ids_a, segment_ids_b = self.batch_chunk(segment_ids)
                    label_ids = torch.chunk(input=label_ids, chunks=2, dim=1)[0][:, 0]
                          
                    aug_mlp_output_a, aug_logits_a = self.model(input_ids_a, segment_ids_a, input_mask_a, mode = 'train')               
                    aug_mlp_output_b, aug_logits_b = self.model(input_ids_b, segment_ids_b, input_mask_b, mode = 'train')

                    loss_ce = 0.5 * (self.criterion(aug_logits_a, label_ids) + self.criterion(aug_logits_b, label_ids))

                    norm_logits = F.normalize(aug_mlp_output_a)
                    norm_aug_logits = F.normalize(aug_mlp_output_b)
                    
                    contrastive_feats = torch.cat((norm_logits.unsqueeze(1), norm_aug_logits.unsqueeze(1)), dim = 1)
                    loss_contrast = self.contrast_criterion(contrastive_feats, labels = label_ids, temperature = args.train_temperature, device = self.device)
            
                    loss = loss_contrast + loss_ce
                    self.optimizer.zero_grad()
                    loss.backward()

                    if args.grad_clip != -1.0:
                        torch.nn.utils.clip_grad_value_([param for param in self.model.parameters() if param.requires_grad], args.grad_clip)

                    tr_loss += loss.item()
                    nb_tr_examples += input_ids.size(0)
                    nb_tr_steps += 1

                    self.optimizer.step()
                    self.scheduler.step()
                
            tr_loss = tr_loss / nb_tr_steps
                
        if args.save_model:
            save_model(self.model, args.model_output_dir)
              
    def test(self, args, data):
        
        outputs = self.get_outputs(args, mode = 'test', model = self.model)
        feats = outputs['feats']
        y_true = outputs['y_true']

        km = KMeans(n_clusters = self.num_labels, n_jobs = -1, random_state=args.seed, init = self.centroids).fit(feats) 
       
        y_pred = km.labels_
        
        test_results = clustering_score(y_true, y_pred)
        cm = confusion_matrix(y_true, y_pred)
        
        self.logger.info
        self.logger.info("***** Test: Confusion Matrix *****")
        self.logger.info("%s", str(cm))
        self.logger.info("***** Test results *****")
        
        for key in sorted(test_results.keys()):
            self.logger.info("  %s = %s", key, str(test_results[key]))

        test_results['y_true'] = y_true
        test_results['y_pred'] = y_pred

        return test_results

    def get_outputs(self, args, mode, model):
        
        if mode == 'test':
            dataloader = self.test_dataloader
        elif mode == 'train':
            dataloader = self.train_dataloader

        model.eval()

        total_labels = torch.empty(0,dtype=torch.long).to(self.device)
        total_preds = torch.empty(0,dtype=torch.long).to(self.device)
        
        total_features = torch.empty((0,args.feat_dim)).to(self.device)
        total_logits = torch.empty((0, self.num_labels)).to(self.device)
        
        for batch in tqdm(dataloader, desc="Iteration"):

            batch = tuple(t.to(self.device) for t in batch)
            input_ids, input_mask, segment_ids, label_ids = batch

            with torch.set_grad_enabled(False):
                pooled_output, logits = model(input_ids, segment_ids, input_mask, feature_ext=True)
                
                total_labels = torch.cat((total_labels,label_ids))
                total_features = torch.cat((total_features, pooled_output))
                total_logits = torch.cat((total_logits, logits))
        
        feats = total_features.cpu().numpy()
        y_true = total_labels.cpu().numpy()
        
        total_probs = F.softmax(total_logits.detach(), dim=1)
        total_maxprobs, total_preds = total_probs.max(dim = 1)
        y_pred = total_preds.cpu().numpy()
        
        y_logits = total_logits.cpu().numpy()
        
        outputs = {
            'y_true': y_true,
            'y_pred': y_pred,
            'logits': y_logits,
            'feats': feats
        }
        return outputs

    def load_pretrained_model(self, args, pretrained_model):
        
        pretrained_dict = pretrained_model.state_dict()
        classifier_params = ['mlp_head.bias','mlp_head.0.bias',  'classifier.weight', 'classifier.bias', 'mlp_head.0.weight', 'mlp_head.weight'] 
        
        pretrained_dict =  {k: v for k, v in pretrained_dict.items() if k not in classifier_params}
        self.model.load_state_dict(pretrained_dict, strict=False)

    def batch_chunk(self, x):
        x1, x2 = torch.chunk(input=x, chunks=2, dim=1)
        x1, x2 = x1.squeeze(1), x2.squeeze(1)
        return x1, x2
    
    def get_augment_dataloader(self, args, train_outputs, pseudo_labels = None):
        
        input_ids = train_outputs['input_ids']
        input_mask = train_outputs['input_mask']
        segment_ids = train_outputs['segment_ids']
        if pseudo_labels is None:
            pseudo_labels = train_outputs['label_ids']
        
        input_ids_a, input_mask_a = self.generator.random_token_erase(input_ids, input_mask)
        input_ids_b, input_mask_b = self.generator.random_token_erase(input_ids, input_mask)
        
        train_input_ids = torch.cat(([input_ids_a.unsqueeze(1), input_ids_b.unsqueeze(1)]), dim = 1)
        train_input_mask = torch.cat(([input_mask_a.unsqueeze(1), input_mask_a.unsqueeze(1)]), dim = 1)
        train_segment_ids = torch.cat(([segment_ids.unsqueeze(1), segment_ids.unsqueeze(1)]), dim = 1)
        
        train_label_ids = torch.tensor(pseudo_labels).unsqueeze(1)
        train_label_ids = torch.cat(([train_label_ids, train_label_ids]), dim = 1)
        
        train_data = TensorDataset(train_input_ids, train_input_mask, train_segment_ids, train_label_ids)

        sampler = RandomSampler(train_data)

        train_dataloader = DataLoader(train_data, sampler = sampler, batch_size = args.train_batch_size)

        return train_dataloader