Flair Regression

flair/data_fetcher.py

@@ -94,6 +94,9 @@ class NLPTask(Enum):
     TREC_6 = "trec-6"
     TREC_50 = "trec-50"
 
+    # text regression format
+    REGRESSION = 'regression'
+
 
 class NLPTaskDataFetcher:
     @staticmethod
@@ -210,6 +213,7 @@ def load_corpus(
             NLPTask.AG_NEWS.value,
             NLPTask.TREC_6.value,
             NLPTask.TREC_50.value,
+            NLPTask.REGRESSION.value,
         ]:
             use_tokenizer: bool = False if task in [
                 NLPTask.TREC_6.value,

flair/models/text_regression_model.py

@@ -0,0 +1,59 @@
+import flair
+import torch
+import torch.nn as nn
+from typing import List, Union
+from flair.training_utils import clear_embeddings
+from flair.data import Sentence, Label
+import logging
+
+log = logging.getLogger('flair')
+
+class TextRegressor(flair.models.TextClassifier):
+
+    def __init__(self,
+                 document_embeddings: flair.embeddings.DocumentEmbeddings,
+                 label_dictionary: flair.data.Dictionary,
+                 multi_label: bool):
+
+        super(TextRegressor, self).__init__(document_embeddings=document_embeddings, label_dictionary=flair.data.Dictionary(), multi_label=multi_label)
+
+        log.info('Using REGRESSION - experimental')
+
+        self.loss_function = nn.MSELoss()
+
+    def _labels_to_indices(self, sentences: List[Sentence]):
+        indices = [
+            torch.FloatTensor([float(label.value) for label in sentence.labels])
+            for sentence in sentences
+        ]
+
+        vec = torch.cat(indices, 0)
+        if torch.cuda.is_available():
+            vec = vec.cuda()
+
+        return vec
+
+    def forward_labels_and_loss(self, sentences: Union[Sentence, List[Sentence]]) -> (List[List[float]], torch.tensor):
+        scores = self.forward(sentences)
+        loss = self._calculate_loss(scores, sentences)
+        return scores, loss
+
+    def predict(self, sentences: Union[Sentence, List[Sentence]], mini_batch_size: int = 32) -> List[Sentence]:
+
+        with torch.no_grad():
+            if type(sentences) is Sentence:
+                sentences = [sentences]
+
+            filtered_sentences = self._filter_empty_sentences(sentences)
+
+            batches = [filtered_sentences[x:x + mini_batch_size] for x in range(0, len(filtered_sentences), mini_batch_size)]
+
+            for batch in batches:
+                scores = self.forward(batch)
+
+                for (sentence, score) in zip(batch, scores.tolist()):
+                  sentence.labels = [Label(value=str(score[0]))]
+
+                clear_embeddings(batch)
+
+            return sentences

flair/trainers/trainer_regression.py

@@ -0,0 +1,147 @@
+import flair
+import torch
+import torch.nn as nn
+
+from typing import List, Union
+from flair.training_utils import MetricRegression, EvaluationMetric, clear_embeddings, log_line
+from flair.models.text_regression_model import TextRegressor
+from flair.data import Sentence, Label
+from pathlib import Path
+import logging
+
+log = logging.getLogger('flair')
+
+class RegressorTrainer(flair.trainers.ModelTrainer):
+
+    def train(self,
+              base_path: Union[Path, str],
+              evaluation_metric: EvaluationMetric = EvaluationMetric.MEAN_SQUARED_ERROR,
+              learning_rate: float = 0.1,
+              mini_batch_size: int = 32,
+              eval_mini_batch_size: int = None,
+              max_epochs: int = 100,
+              anneal_factor: float = 0.5,
+              patience: int = 3,
+              anneal_against_train_loss: bool = True,
+              train_with_dev: bool = False,
+              monitor_train: bool = False,
+              embeddings_in_memory: bool = True,
+              checkpoint: bool = False,
+              save_final_model: bool = True,
+              anneal_with_restarts: bool = False,
+              test_mode: bool = False,
+              param_selection_mode: bool = False,
+              **kwargs
+              ) -> dict:
+
+        return super(RegressorTrainer, self).train(
+              base_path=base_path, 
+              evaluation_metric=evaluation_metric, 
+              learning_rate=learning_rate,
+              mini_batch_size=mini_batch_size,
+              eval_mini_batch_size=eval_mini_batch_size,
+              max_epochs=max_epochs,
+              anneal_factor=anneal_factor,
+              patience=patience,
+              anneal_against_train_loss=anneal_against_train_loss,
+              train_with_dev=train_with_dev,
+              monitor_train=monitor_train,
+              embeddings_in_memory=embeddings_in_memory,
+              checkpoint=checkpoint,
+              save_final_model=save_final_model,
+              anneal_with_restarts=anneal_with_restarts,
+              test_mode=test_mode,
+              param_selection_mode=param_selection_mode)
+
+    @staticmethod
+    def _evaluate_text_regressor(model: flair.nn.Model,
+                                  sentences: List[Sentence],
+                                  eval_mini_batch_size: int = 32,
+                                  embeddings_in_memory: bool = False,
+                                  out_path: Path = None) -> (dict, float):
+
+        with torch.no_grad():
+            eval_loss = 0
+
+            batches = [sentences[x:x + eval_mini_batch_size] for x in
+                       range(0, len(sentences), eval_mini_batch_size)]
+
+            metric = MetricRegression('Evaluation')
+
+            lines: List[str] = []
+            for batch in batches:
+
+                scores, loss = model.forward_labels_and_loss(batch)
+
+                true_values = []
+                for sentence in batch:
+                  for label in sentence.labels:
+                    true_values.append(float(label.value))
+
+                results = []
+                for score in scores:
+                  if type(score[0]) is Label:
+                    results.append(float(score[0].score))
+                  else:
+                    results.append(float(score[0]))
+
+                clear_embeddings(batch, also_clear_word_embeddings=not embeddings_in_memory)
+
+                eval_loss += loss
+
+                metric.true.extend(true_values)
+                metric.pred.extend(results)
+
+            eval_loss /= len(sentences)
+
+            ##TODO: not saving lines yet
+            if out_path is not None:
+                with open(out_path, "w", encoding='utf-8') as outfile:
+                    outfile.write(''.join(lines))
+
+            return metric, eval_loss
+
+
+    def _calculate_evaluation_results_for(self,
+                                          dataset_name: str,
+                                          dataset: List[Sentence],
+                                          evaluation_metric: EvaluationMetric,
+                                          embeddings_in_memory: bool,
+                                          eval_mini_batch_size: int,
+                                          out_path: Path = None):
+
+        metric, loss = RegressorTrainer._evaluate_text_regressor(self.model, dataset, eval_mini_batch_size=eval_mini_batch_size,
+                                             embeddings_in_memory=embeddings_in_memory, out_path=out_path)
+
+        mse = metric.mean_squared_error()
+        mae = metric.mean_absolute_error()
+
+        log.info(f'{dataset_name:<5}: loss {loss:.8f} - mse {mse:.4f} - mae {mae:.4f}')
+
+        return metric, loss
+
+    def final_test(self,
+                   base_path: Path,
+                   embeddings_in_memory: bool,
+                   evaluation_metric: EvaluationMetric,
+                   eval_mini_batch_size: int):
+
+        log_line(log)
+        log.info('Testing using best model ...')
+
+        self.model.eval()
+
+        if (base_path / 'best-model.pt').exists():
+            self.model = TextRegressor.load_from_file(base_path / 'best-model.pt')
+
+        test_metric, test_loss = self._evaluate_text_regressor(self.model, self.corpus.test, eval_mini_batch_size=eval_mini_batch_size,
+                                               embeddings_in_memory=embeddings_in_memory)
+
+        log.info(f'AVG: mse: {test_metric.mean_squared_error():.4f} - '
+                 f'mae: {test_metric.mean_absolute_error():.4f} - '
+                 f'pearson: {test_metric.pearsonr():.4f} - '
+                 f'spearman: {test_metric.spearmanr():.4f}')
+
+        log_line(log)
+
+        return test_metric.mean_squared_error()

flair/training_utils.py

@@ -7,6 +7,8 @@
 from typing import List
 from flair.data import Dictionary, Sentence
 from functools import reduce
+from sklearn.metrics import mean_squared_error, mean_absolute_error
+from scipy.stats import pearsonr, spearmanr
 
 
 class Metric(object):
@@ -171,11 +173,65 @@ def __str__(self):
         return "\n".join(all_lines)
 
 
+class MetricRegression(object):
+
+    def __init__(self, name):
+        self.name = name
+
+        self.true = []
+        self.pred = []
+
+    def mean_squared_error(self):
+        return mean_squared_error(self.true, self.pred)
+
+    def mean_absolute_error(self):
+        return mean_absolute_error(self.true, self.pred)
+
+    def pearsonr(self):
+        return pearsonr(self.true, self.pred)[0]
+
+    def spearmanr(self):
+        return spearmanr(self.true, self.pred)[0]
+
+    ## dummy return to fulfill trainer.train() needs
+    def micro_avg_f_score(self):
+        return self.mean_squared_error()
+
+    def to_tsv(self):
+        return '{}\t{}\t{}\t{}'.format(
+            self.mean_squared_error(),
+            self.mean_absolute_error(),
+            self.pearsonr(),
+            self.spearmanr(),
+        )
+
+    @staticmethod
+    def tsv_header(prefix=None):
+        if prefix:
+            return '{0}_MEAN_SQUARED_ERROR\t{0}_MEAN_ABSOLUTE_ERROR\t{0}_PEARSON\t{0}_SPEARMAN'.format(
+                prefix)
+
+        return 'MEAN_SQUARED_ERROR\tMEAN_ABSOLUTE_ERROR\tPEARSON\tSPEARMAN'
+
+    @staticmethod
+    def to_empty_tsv():
+        return '\t_\t_\t_\t_'
+
+    def __str__(self):
+        line = 'mean squared error: {0:.4f} - mean absolute error: {1:.4f} - pearson: {2:.4f} - spearman: {3:.4f}'.format(
+                self.mean_squared_error(),
+                self.mean_absolute_error(),
+                self.pearsonr(),
+                self.spearmanr())
+        return line
+
+
 class EvaluationMetric(Enum):
-    MICRO_ACCURACY = "micro-average accuracy"
-    MICRO_F1_SCORE = "micro-average f1-score"
-    MACRO_ACCURACY = "macro-average accuracy"
-    MACRO_F1_SCORE = "macro-average f1-score"
+    MICRO_ACCURACY = 'micro-average accuracy'
+    MICRO_F1_SCORE = 'micro-average f1-score'
+    MACRO_ACCURACY = 'macro-average accuracy'
+    MACRO_F1_SCORE = 'macro-average f1-score'
+    MEAN_SQUARED_ERROR = 'mean squared error'
 
 
 class WeightExtractor(object):

tests/resources/tasks/regression/README.md

@@ -0,0 +1,14 @@
+## REGRESSION
+
+Data is taken from [here](http://saifmohammad.com/WebPages/EmotionIntensity-SharedTask.html).
+
+The dataset contains a collection of tweets with joy intensity value.
+We took the joy dataset and converted it to the expected format of our data fetcher:
+```
+__label__<joy_intensity> <text>
+```
+
+#### Publication About the Dataset
+
+* Emotion Intensities in Tweets. Saif M. Mohammad and Felipe Bravo-Marquez. In Proceedings of the sixth joint conference on lexical and computational semantics (*Sem), August 2017, Vancouver, Canada.
+* WASSA-2017 Shared Task on Emotion Intensity. Saif M. Mohammad and Felipe Bravo-Marquez. In Proceedings of the EMNLP 2017 Workshop on Computational Approaches to Subjectivity, Sentiment, and Social Media (WASSA), September 2017, Copenhagen, Denmark.