Bagaimana mengatasi masalah di Kaggle dengan TF-Hub

Lihat di TensorFlow.org Jalankan di Google Colab Lihat di GitHub Unduh buku catatan Lihat model TF Hub

TF-Hub adalah platform untuk berbagi keahlian pembelajaran mesin dikemas dalam sumber daya dapat digunakan kembali, modul terutama pra-dilatih. Dalam tutorial ini, kita akan menggunakan modul penyisipan teks TF-Hub untuk melatih pengklasifikasi sentimen sederhana dengan akurasi dasar yang wajar. Kami kemudian akan mengirimkan prediksi ke Kaggle.

Untuk tutorial lebih rinci tentang klasifikasi teks dengan TF-Hub dan langkah-langkah lebih lanjut untuk meningkatkan akurasi, lihatlah klasifikasi Teks dengan TF-Hub .

Mempersiapkan

pip install -q kaggle

import tensorflow as tf
import tensorflow_hub as hub
import matplotlib.pyplot as plt
import numpy as np
import pandas as pd
import seaborn as sns
import zipfile

from sklearn import model_selection

Sejak tutorial ini akan menggunakan dataset dari Kaggle, itu membutuhkan menciptakan API Token untuk akun Kaggle Anda, dan meng-upload ke lingkungan CoLab.

import os
import pathlib

# Upload the API token.
def get_kaggle():
  try:
    import kaggle
    return kaggle
  except OSError:
    pass

  token_file = pathlib.Path("~/.kaggle/kaggle.json").expanduser()
  token_file.parent.mkdir(exist_ok=True, parents=True)

  try:
    from google.colab import files
  except ImportError:
    raise ValueError("Could not find kaggle token.")

  uploaded = files.upload()
  token_content = uploaded.get('kaggle.json', None)
  if token_content:
    token_file.write_bytes(token_content)
    token_file.chmod(0o600)
  else:
    raise ValueError('Need a file named "kaggle.json"')

  import kaggle
  return kaggle


kaggle = get_kaggle()

Mulai

Data

Kami akan mencoba untuk memecahkan Analisis Sentimen di Film Ulasan tugas dari Kaggle. Dataset terdiri dari subfrase sintaksis ulasan film Rotten Tomatoes. Tugas kita adalah untuk label frase negatif atau positif pada skala dari 1 sampai 5.

Anda harus menerima aturan kompetisi sebelum Anda dapat menggunakan API untuk men-download data.

SENTIMENT_LABELS = [
    "negative", "somewhat negative", "neutral", "somewhat positive", "positive"
]

# Add a column with readable values representing the sentiment.
def add_readable_labels_column(df, sentiment_value_column):
  df["SentimentLabel"] = df[sentiment_value_column].replace(
      range(5), SENTIMENT_LABELS)

# Download data from Kaggle and create a DataFrame.
def load_data_from_zip(path):
  with zipfile.ZipFile(path, "r") as zip_ref:
    name = zip_ref.namelist()[0]
    with zip_ref.open(name) as zf:
      return pd.read_csv(zf, sep="\t", index_col=0)


# The data does not come with a validation set so we'll create one from the
# training set.
def get_data(competition, train_file, test_file, validation_set_ratio=0.1):
  data_path = pathlib.Path("data")
  kaggle.api.competition_download_files(competition, data_path)
  competition_path = (data_path/competition)
  competition_path.mkdir(exist_ok=True, parents=True)
  competition_zip_path = competition_path.with_suffix(".zip")

  with zipfile.ZipFile(competition_zip_path, "r") as zip_ref:
    zip_ref.extractall(competition_path)

  train_df = load_data_from_zip(competition_path/train_file)
  test_df = load_data_from_zip(competition_path/test_file)

  # Add a human readable label.
  add_readable_labels_column(train_df, "Sentiment")

  # We split by sentence ids, because we don't want to have phrases belonging
  # to the same sentence in both training and validation set.
  train_indices, validation_indices = model_selection.train_test_split(
      np.unique(train_df["SentenceId"]),
      test_size=validation_set_ratio,
      random_state=0)

  validation_df = train_df[train_df["SentenceId"].isin(validation_indices)]
  train_df = train_df[train_df["SentenceId"].isin(train_indices)]
  print("Split the training data into %d training and %d validation examples." %
        (len(train_df), len(validation_df)))

  return train_df, validation_df, test_df


train_df, validation_df, test_df = get_data(
    "sentiment-analysis-on-movie-reviews",
    "train.tsv.zip", "test.tsv.zip")

Split the training data into 140315 training and 15745 validation examples.

train_df.head(20)

Melatih Model

class MyModel(tf.keras.Model):
  def __init__(self, hub_url):
    super().__init__()
    self.hub_url = hub_url
    self.embed = hub.load(self.hub_url).signatures['default']
    self.sequential = tf.keras.Sequential([
      tf.keras.layers.Dense(500),
      tf.keras.layers.Dense(100),
      tf.keras.layers.Dense(5),
    ])

  def call(self, inputs):
    phrases = inputs['Phrase'][:,0]
    embedding = 5*self.embed(phrases)['default']
    return self.sequential(embedding)

  def get_config(self):
    return {"hub_url":self.hub_url}

model = MyModel("https://tfhub.dev/google/nnlm-en-dim128/1")
model.compile(
    loss = tf.losses.SparseCategoricalCrossentropy(from_logits=True),
    optimizer=tf.optimizers.Adam(), 
    metrics = [tf.keras.metrics.SparseCategoricalAccuracy(name="accuracy")])

history = model.fit(x=dict(train_df), y=train_df['Sentiment'],
          validation_data=(dict(validation_df), validation_df['Sentiment']),
          epochs = 25)

Epoch 1/25
4385/4385 [==============================] - 16s 3ms/step - loss: 1.0237 - accuracy: 0.5869 - val_loss: 1.0023 - val_accuracy: 0.5870
Epoch 2/25
4385/4385 [==============================] - 15s 3ms/step - loss: 0.9995 - accuracy: 0.5941 - val_loss: 0.9903 - val_accuracy: 0.5952
Epoch 3/25
4385/4385 [==============================] - 15s 3ms/step - loss: 0.9946 - accuracy: 0.5967 - val_loss: 0.9811 - val_accuracy: 0.6011
Epoch 4/25
4385/4385 [==============================] - 15s 3ms/step - loss: 0.9924 - accuracy: 0.5971 - val_loss: 0.9851 - val_accuracy: 0.5935
Epoch 5/25
4385/4385 [==============================] - 15s 3ms/step - loss: 0.9912 - accuracy: 0.5988 - val_loss: 0.9896 - val_accuracy: 0.5934
Epoch 6/25
4385/4385 [==============================] - 15s 3ms/step - loss: 0.9896 - accuracy: 0.5984 - val_loss: 0.9810 - val_accuracy: 0.5936
Epoch 7/25
4385/4385 [==============================] - 15s 3ms/step - loss: 0.9892 - accuracy: 0.5978 - val_loss: 0.9845 - val_accuracy: 0.5994
Epoch 8/25
4385/4385 [==============================] - 15s 3ms/step - loss: 0.9889 - accuracy: 0.5996 - val_loss: 0.9772 - val_accuracy: 0.6015
Epoch 9/25
4385/4385 [==============================] - 15s 3ms/step - loss: 0.9880 - accuracy: 0.5992 - val_loss: 0.9798 - val_accuracy: 0.5991
Epoch 10/25
4385/4385 [==============================] - 15s 3ms/step - loss: 0.9879 - accuracy: 0.6002 - val_loss: 0.9869 - val_accuracy: 0.5935
Epoch 11/25
4385/4385 [==============================] - 15s 3ms/step - loss: 0.9878 - accuracy: 0.5998 - val_loss: 0.9790 - val_accuracy: 0.5985
Epoch 12/25
4385/4385 [==============================] - 14s 3ms/step - loss: 0.9871 - accuracy: 0.5999 - val_loss: 0.9845 - val_accuracy: 0.5964
Epoch 13/25
4385/4385 [==============================] - 15s 3ms/step - loss: 0.9871 - accuracy: 0.6001 - val_loss: 0.9800 - val_accuracy: 0.5947
Epoch 14/25
4385/4385 [==============================] - 15s 3ms/step - loss: 0.9873 - accuracy: 0.6001 - val_loss: 0.9810 - val_accuracy: 0.5934
Epoch 15/25
4385/4385 [==============================] - 14s 3ms/step - loss: 0.9865 - accuracy: 0.5988 - val_loss: 0.9824 - val_accuracy: 0.5898
Epoch 16/25
4385/4385 [==============================] - 15s 3ms/step - loss: 0.9865 - accuracy: 0.5993 - val_loss: 0.9779 - val_accuracy: 0.5974
Epoch 17/25
4385/4385 [==============================] - 15s 3ms/step - loss: 0.9866 - accuracy: 0.5991 - val_loss: 0.9785 - val_accuracy: 0.5972
Epoch 18/25
4385/4385 [==============================] - 15s 3ms/step - loss: 0.9863 - accuracy: 0.6001 - val_loss: 0.9803 - val_accuracy: 0.5991
Epoch 19/25
4385/4385 [==============================] - 16s 4ms/step - loss: 0.9863 - accuracy: 0.5996 - val_loss: 0.9773 - val_accuracy: 0.5957
Epoch 20/25
4385/4385 [==============================] - 15s 3ms/step - loss: 0.9862 - accuracy: 0.5995 - val_loss: 0.9744 - val_accuracy: 0.6009
Epoch 21/25
4385/4385 [==============================] - 15s 3ms/step - loss: 0.9861 - accuracy: 0.5997 - val_loss: 0.9787 - val_accuracy: 0.5968
Epoch 22/25
4385/4385 [==============================] - 15s 3ms/step - loss: 0.9855 - accuracy: 0.5998 - val_loss: 0.9794 - val_accuracy: 0.5976
Epoch 23/25
4385/4385 [==============================] - 14s 3ms/step - loss: 0.9861 - accuracy: 0.5998 - val_loss: 0.9778 - val_accuracy: 0.5966
Epoch 24/25
4385/4385 [==============================] - 15s 3ms/step - loss: 0.9860 - accuracy: 0.5999 - val_loss: 0.9831 - val_accuracy: 0.5912
Epoch 25/25
4385/4385 [==============================] - 14s 3ms/step - loss: 0.9858 - accuracy: 0.5999 - val_loss: 0.9780 - val_accuracy: 0.5977

Ramalan

Jalankan prediksi untuk set validasi dan set pelatihan.

plt.plot(history.history['accuracy'])
plt.plot(history.history['val_accuracy'])

[<matplotlib.lines.Line2D at 0x7f62684da090>]

png

train_eval_result = model.evaluate(dict(train_df), train_df['Sentiment'])
validation_eval_result = model.evaluate(dict(validation_df), validation_df['Sentiment'])

print(f"Training set accuracy: {train_eval_result[1]}")
print(f"Validation set accuracy: {validation_eval_result[1]}")

4385/4385 [==============================] - 14s 3ms/step - loss: 0.9834 - accuracy: 0.6007
493/493 [==============================] - 1s 2ms/step - loss: 0.9780 - accuracy: 0.5977
Training set accuracy: 0.6006770730018616
Validation set accuracy: 0.5976500511169434

Matriks kebingungan

Statistik lain yang sangat menarik, terutama untuk masalah multiclass, adalah matriks kebingungan . Matriks kebingungan memungkinkan visualisasi proporsi contoh yang diberi label dengan benar dan salah. Kita dapat dengan mudah melihat seberapa bias classifier kita dan apakah distribusi label masuk akal. Idealnya fraksi terbesar dari prediksi harus didistribusikan sepanjang diagonal.

predictions = model.predict(dict(validation_df))
predictions = tf.argmax(predictions, axis=-1)
predictions

<tf.Tensor: shape=(15745,), dtype=int64, numpy=array([1, 1, 2, ..., 2, 2, 2])>

cm = tf.math.confusion_matrix(validation_df['Sentiment'], predictions)
cm = cm/cm.numpy().sum(axis=1)[:, tf.newaxis]

sns.heatmap(
    cm, annot=True,
    xticklabels=SENTIMENT_LABELS,
    yticklabels=SENTIMENT_LABELS)
plt.xlabel("Predicted")
plt.ylabel("True")

Text(32.99999999999999, 0.5, 'True')

png

Kita dapat dengan mudah mengirimkan prediksi kembali ke Kaggle dengan menempelkan kode berikut ke sel kode dan menjalankannya:

test_predictions = model.predict(dict(test_df))
test_predictions = np.argmax(test_predictions, axis=-1)

result_df = test_df.copy()

result_df["Predictions"] = test_predictions

result_df.to_csv(
    "predictions.csv",
    columns=["Predictions"],
    header=["Sentiment"])
kaggle.api.competition_submit("predictions.csv", "Submitted from Colab",
                              "sentiment-analysis-on-movie-reviews")

Setelah mengirimkan, periksa leaderboard untuk melihat bagaimana Anda melakukannya.