TensorFlow Hub ile metin sınıflandırması: Film incelemeleri

TensorFlow.org'da görüntüleyin Google Colab'da çalıştırın GitHub'da görüntüle Not defterini indir TF Hub modellerine bakın

Bu defter, inceleme metnini kullanarak film incelemelerini olumlu veya olumsuz olarak sınıflandırır. Bu, önemli ve yaygın olarak uygulanabilir bir makine öğrenimi problemi türü olan ikili —veya iki sınıflı— sınıflandırmanın bir örneğidir.

Eğitim, TensorFlow Hub ve Keras ile transfer öğreniminin temel uygulamasını gösterir.

İnternet Film Veritabanından 50.000 film incelemesi metnini içeren IMDB veri setini kullanır. Bunlar, eğitim için 25.000 inceleme ve test için 25.000 incelemeye bölünmüştür. Eğitim ve test setleri dengelidir , yani eşit sayıda olumlu ve olumsuz inceleme içerirler.

Bu not defteri, tf.keras modeller oluşturmak ve eğitmek için üst düzey bir API olan tf.keras ve tensorflow_hub eğitimli modelleri tek bir kod satırında yüklemek için bir kitaplık olan tensorflow_hub kullanır . tf.keras kullanarak daha gelişmiş bir metin sınıflandırma eğitimi için tf.keras Metin Sınıflandırma Kılavuzuna bakın.

pip install tensorflow-hub
pip install tensorflow-datasets
import os
import numpy as np

import tensorflow as tf
import tensorflow_hub as hub
import tensorflow_datasets as tfds

print("Version: ", tf.__version__)
print("Eager mode: ", tf.executing_eagerly())
print("Hub version: ", hub.__version__)
print("GPU is", "available" if tf.config.list_physical_devices("GPU") else "NOT AVAILABLE")
-yer tutucu2 l10n-yer
Version:  2.8.0-rc1
Eager mode:  True
Hub version:  0.12.0
GPU is available

IMDB veri setini indirin

IMDB veri kümesi, imdb incelemelerinde veya TensorFlow veri kümelerinde mevcuttur. Aşağıdaki kod, IMDB veri kümesini makinenize (veya ortak çalışma zamanına) indirir:

# Split the training set into 60% and 40% to end up with 15,000 examples
# for training, 10,000 examples for validation and 25,000 examples for testing.
train_data, validation_data, test_data = tfds.load(
    split=('train[:60%]', 'train[60%:]', 'test'),

Verileri keşfedin

Verilerin biçimini anlamak için bir dakikanızı ayıralım. Her örnek, film incelemesini ve buna karşılık gelen bir etiketi temsil eden bir cümledir. Cümle hiçbir şekilde ön işleme tabi tutulmaz. Etiket, 0 veya 1 tamsayı değeridir; burada 0, olumsuz bir incelemedir ve 1, olumlu bir incelemedir.

İlk 10 örneği yazdıralım.

train_examples_batch, train_labels_batch = next(iter(train_data.batch(10)))
tutucu5 l10n-yer
<tf.Tensor: shape=(10,), dtype=string, numpy=
array([b"This was an absolutely terrible movie. Don't be lured in by Christopher Walken or Michael Ironside. Both are great actors, but this must simply be their worst role in history. Even their great acting could not redeem this movie's ridiculous storyline. This movie is an early nineties US propaganda piece. The most pathetic scenes were those when the Columbian rebels were making their cases for revolutions. Maria Conchita Alonso appeared phony, and her pseudo-love affair with Walken was nothing but a pathetic emotional plug in a movie that was devoid of any real meaning. I am disappointed that there are movies like this, ruining actor's like Christopher Walken's good name. I could barely sit through it.",
       b'I have been known to fall asleep during films, but this is usually due to a combination of things including, really tired, being warm and comfortable on the sette and having just eaten a lot. However on this occasion I fell asleep because the film was rubbish. The plot development was constant. Constantly slow and boring. Things seemed to happen, but with no explanation of what was causing them or why. I admit, I may have missed part of the film, but i watched the majority of it and everything just seemed to happen of its own accord without any real concern for anything else. I cant recommend this film at all.',
       b'Mann photographs the Alberta Rocky Mountains in a superb fashion, and Jimmy Stewart and Walter Brennan give enjoyable performances as they always seem to do. <br /><br />But come on Hollywood - a Mountie telling the people of Dawson City, Yukon to elect themselves a marshal (yes a marshal!) and to enforce the law themselves, then gunfighters battling it out on the streets for control of the town? <br /><br />Nothing even remotely resembling that happened on the Canadian side of the border during the Klondike gold rush. Mr. Mann and company appear to have mistaken Dawson City for Deadwood, the Canadian North for the American Wild West.<br /><br />Canadian viewers be prepared for a Reefer Madness type of enjoyable howl with this ludicrous plot, or, to shake your head in disgust.',
       b'This is the kind of film for a snowy Sunday afternoon when the rest of the world can go ahead with its own business as you descend into a big arm-chair and mellow for a couple of hours. Wonderful performances from Cher and Nicolas Cage (as always) gently row the plot along. There are no rapids to cross, no dangerous waters, just a warm and witty paddle through New York life at its best. A family film in every sense and one that deserves the praise it received.',
       b'As others have mentioned, all the women that go nude in this film are mostly absolutely gorgeous. The plot very ably shows the hypocrisy of the female libido. When men are around they want to be pursued, but when no "men" are around, they become the pursuers of a 14 year old boy. And the boy becomes a man really fast (we should all be so lucky at this age!). He then gets up the courage to pursue his true love.',
       b"This is a film which should be seen by anybody interested in, effected by, or suffering from an eating disorder. It is an amazingly accurate and sensitive portrayal of bulimia in a teenage girl, its causes and its symptoms. The girl is played by one of the most brilliant young actresses working in cinema today, Alison Lohman, who was later so spectacular in 'Where the Truth Lies'. I would recommend that this film be shown in all schools, as you will never see a better on this subject. Alison Lohman is absolutely outstanding, and one marvels at her ability to convey the anguish of a girl suffering from this compulsive disorder. If barometers tell us the air pressure, Alison Lohman tells us the emotional pressure with the same degree of accuracy. Her emotional range is so precise, each scene could be measured microscopically for its gradations of trauma, on a scale of rising hysteria and desperation which reaches unbearable intensity. Mare Winningham is the perfect choice to play her mother, and does so with immense sympathy and a range of emotions just as finely tuned as Lohman's. Together, they make a pair of sensitive emotional oscillators vibrating in resonance with one another. This film is really an astonishing achievement, and director Katt Shea should be proud of it. The only reason for not seeing it is if you are not interested in people. But even if you like nature films best, this is after all animal behaviour at the sharp edge. Bulimia is an extreme version of how a tormented soul can destroy her own body in a frenzy of despair. And if we don't sympathise with people suffering from the depths of despair, then we are dead inside.",
       b'Okay, you have:<br /><br />Penelope Keith as Miss Herringbone-Tweed, B.B.E. (Backbone of England.) She\'s killed off in the first scene - that\'s right, folks; this show has no backbone!<br /><br />Peter O\'Toole as Ol\' Colonel Cricket from The First War and now the emblazered Lord of the Manor.<br /><br />Joanna Lumley as the ensweatered Lady of the Manor, 20 years younger than the colonel and 20 years past her own prime but still glamourous (Brit spelling, not mine) enough to have a toy-boy on the side. It\'s alright, they have Col. Cricket\'s full knowledge and consent (they guy even comes \'round for Christmas!) Still, she\'s considerate of the colonel enough to have said toy-boy her own age (what a gal!)<br /><br />David McCallum as said toy-boy, equally as pointlessly glamourous as his squeeze. Pilcher couldn\'t come up with any cover for him within the story, so she gave him a hush-hush job at the Circus.<br /><br />and finally:<br /><br />Susan Hampshire as Miss Polonia Teacups, Venerable Headmistress of the Venerable Girls\' Boarding-School, serving tea in her office with a dash of deep, poignant advice for life in the outside world just before graduation. Her best bit of advice: "I\'ve only been to Nancherrow (the local Stately Home of England) once. I thought it was very beautiful but, somehow, not part of the real world." Well, we can\'t say they didn\'t warn us.<br /><br />Ah, Susan - time was, your character would have been running the whole show. They don\'t write \'em like that any more. Our loss, not yours.<br /><br />So - with a cast and setting like this, you have the re-makings of "Brideshead Revisited," right?<br /><br />Wrong! They took these 1-dimensional supporting roles because they paid so well. After all, acting is one of the oldest temp-jobs there is (YOU name another!)<br /><br />First warning sign: lots and lots of backlighting. They get around it by shooting outdoors - "hey, it\'s just the sunlight!"<br /><br />Second warning sign: Leading Lady cries a lot. When not crying, her eyes are moist. That\'s the law of romance novels: Leading Lady is "dewy-eyed."<br /><br />Henceforth, Leading Lady shall be known as L.L.<br /><br />Third warning sign: L.L. actually has stars in her eyes when she\'s in love. Still, I\'ll give Emily Mortimer an award just for having to act with that spotlight in her eyes (I wonder . did they use contacts?)<br /><br />And lastly, fourth warning sign: no on-screen female character is "Mrs." She\'s either "Miss" or "Lady."<br /><br />When all was said and done, I still couldn\'t tell you who was pursuing whom and why. I couldn\'t even tell you what was said and done.<br /><br />To sum up: they all live through World War II without anything happening to them at all.<br /><br />OK, at the end, L.L. finds she\'s lost her parents to the Japanese prison camps and baby sis comes home catatonic. Meanwhile (there\'s always a "meanwhile,") some young guy L.L. had a crush on (when, I don\'t know) comes home from some wartime tough spot and is found living on the street by Lady of the Manor (must be some street if SHE\'s going to find him there.) Both war casualties are whisked away to recover at Nancherrow (SOMEBODY has to be "whisked away" SOMEWHERE in these romance stories!)<br /><br />Great drama.',
       b'The film is based on a genuine 1950s novel.<br /><br />Journalist Colin McInnes wrote a set of three "London novels": "Absolute Beginners", "City of Spades" and "Mr Love and Justice". I have read all three. The first two are excellent. The last, perhaps an experiment that did not come off. But McInnes\'s work is highly acclaimed; and rightly so. This musical is the novelist\'s ultimate nightmare - to see the fruits of one\'s mind being turned into a glitzy, badly-acted, soporific one-dimensional apology of a film that says it captures the spirit of 1950s London, and does nothing of the sort.<br /><br />Thank goodness Colin McInnes wasn\'t alive to witness it.',
       b'I really love the sexy action and sci-fi films of the sixties and its because of the actress\'s that appeared in them. They found the sexiest women to be in these films and it didn\'t matter if they could act (Remember "Candy"?). The reason I was disappointed by this film was because it wasn\'t nostalgic enough. The story here has a European sci-fi film called "Dragonfly" being made and the director is fired. So the producers decide to let a young aspiring filmmaker (Jeremy Davies) to complete the picture. They\'re is one real beautiful woman in the film who plays Dragonfly but she\'s barely in it. Film is written and directed by Roman Coppola who uses some of his fathers exploits from his early days and puts it into the script. I wish the film could have been an homage to those early films. They could have lots of cameos by actors who appeared in them. There is one actor in this film who was popular from the sixties and its John Phillip Law (Barbarella). Gerard Depardieu, Giancarlo Giannini and Dean Stockwell appear as well. I guess I\'m going to have to continue waiting for a director to make a good homage to the films of the sixties. If any are reading this, "Make it as sexy as you can"! I\'ll be waiting!',
       b'Sure, this one isn\'t really a blockbuster, nor does it target such a position. "Dieter" is the first name of a quite popular German musician, who is either loved or hated for his kind of acting and thats exactly what this movie is about. It is based on the autobiography "Dieter Bohlen" wrote a few years ago but isn\'t meant to be accurate on that. The movie is filled with some sexual offensive content (at least for American standard) which is either amusing (not for the other "actors" of course) or dumb - it depends on your individual kind of humor or on you being a "Bohlen"-Fan or not. Technically speaking there isn\'t much to criticize. Speaking of me I find this movie to be an OK-movie.'],

İlk 10 etiketi de yazdıralım.

tutucu7 l10n-yer
<tf.Tensor: shape=(10,), dtype=int64, numpy=array([0, 0, 0, 1, 1, 1, 0, 0, 0, 0])>

Modeli oluşturun

Sinir ağı, katmanları istifleyerek oluşturulur; bu, üç ana mimari karar gerektirir:

  • Metin nasıl temsil edilir?
  • Modelde kaç katman kullanılacak?
  • Her katman için kaç tane gizli birim kullanılacak?

Bu örnekte, giriş verileri cümlelerden oluşmaktadır. Tahmin edilecek etiketler ya 0 ya da 1'dir.

Metni temsil etmenin bir yolu, cümleleri gömme vektörlerine dönüştürmektir. İlk katman olarak önceden eğitilmiş bir metin gömme kullanın; bu, üç avantajı olacaktır:

  • Metin ön işleme konusunda endişelenmenize gerek yok,
  • Transfer öğrenmeden yararlanın,
  • gömmenin sabit bir boyutu vardır, bu nedenle işlenmesi daha kolaydır.

Bu örnek için, TensorFlow Hub'dan google/nnlm-en-dim50/2 adlı önceden eğitilmiş bir metin gömme modeli kullanıyorsunuz.

Bu eğitimde kullanılabilecek TFHub'dan önceden eğitilmiş birçok metin yerleştirmesi vardır:

  • google/nnlm-en-dim128/2 - google/nnlm-en-dim50/2 ile aynı veriler üzerinde aynı NNLM mimarisiyle eğitildi , ancak daha büyük bir yerleştirme boyutuyla. Daha büyük boyutlu yerleştirmeler işinizi iyileştirebilir ancak modelinizi eğitmek daha uzun sürebilir.
  • google/nnlm-en-dim128-with-normalization/2 - google/nnlm-en-dim128/2 ile aynı, ancak noktalama işaretlerini kaldırmak gibi ek metin normalleştirmesi var. Bu, görevinizdeki metin ek karakterler veya noktalama işaretleri içeriyorsa yardımcı olabilir.
  • google/universal-sentence-encoder/4 - derin ortalamalı ağ (DAN) kodlayıcı ile eğitilmiş 512 boyutlu yerleştirmeler sağlayan çok daha büyük bir model.

Ve daha fazlası! TFHub'da daha fazla metin gömme modeli bulun.

Önce cümleleri gömmek için TensorFlow Hub modelini kullanan bir Keras katmanı oluşturalım ve bunu birkaç giriş örneğinde deneyelim. Giriş metninin uzunluğu ne olursa olsun, gömmelerin çıkış şeklinin: (num_examples, embedding_dimension) olduğunu unutmayın.

embedding = "https://tfhub.dev/google/nnlm-en-dim50/2"
hub_layer = hub.KerasLayer(embedding, input_shape=[], 
                           dtype=tf.string, trainable=True)
tutucu9 l10n-yer
<tf.Tensor: shape=(3, 50), dtype=float32, numpy=
array([[ 0.5423194 , -0.01190171,  0.06337537,  0.0686297 , -0.16776839,
        -0.10581177,  0.168653  , -0.04998823, -0.31148052,  0.07910344,
         0.15442258,  0.01488661,  0.03930155,  0.19772716, -0.12215477,
        -0.04120982, -0.27041087, -0.21922147,  0.26517656, -0.80739075,
         0.25833526, -0.31004202,  0.2868321 ,  0.19433866, -0.29036498,
         0.0386285 , -0.78444123, -0.04793238,  0.41102988, -0.36388886,
        -0.58034706,  0.30269453,  0.36308962, -0.15227163, -0.4439151 ,
         0.19462997,  0.19528405,  0.05666233,  0.2890704 , -0.28468323,
        -0.00531206,  0.0571938 , -0.3201319 , -0.04418665, -0.08550781,
        -0.55847436, -0.2333639 , -0.20782956, -0.03543065, -0.17533456],
       [ 0.56338924, -0.12339553, -0.10862677,  0.7753425 , -0.07667087,
        -0.15752274,  0.01872334, -0.08169781, -0.3521876 ,  0.46373403,
        -0.08492758,  0.07166861, -0.00670818,  0.12686071, -0.19326551,
        -0.5262643 , -0.32958236,  0.14394784,  0.09043556, -0.54175544,
         0.02468163, -0.15456744,  0.68333143,  0.09068333, -0.45327246,
         0.23180094, -0.8615696 ,  0.3448039 ,  0.12838459, -0.58759046,
        -0.40712303,  0.23061076,  0.48426905, -0.2712814 , -0.5380918 ,
         0.47016335,  0.2257274 , -0.00830665,  0.28462422, -0.30498496,
         0.04400366,  0.25025868,  0.14867125,  0.4071703 , -0.15422425,
        -0.06878027, -0.40825695, -0.31492147,  0.09283663, -0.20183429],
       [ 0.7456156 ,  0.21256858,  0.1440033 ,  0.52338624,  0.11032254,
         0.00902788, -0.36678016, -0.08938274, -0.24165548,  0.33384597,
        -0.111946  , -0.01460045, -0.00716449,  0.19562715,  0.00685217,
        -0.24886714, -0.42796353,  0.1862    , -0.05241097, -0.664625  ,
         0.13449019, -0.22205493,  0.08633009,  0.43685383,  0.2972681 ,
         0.36140728, -0.71968895,  0.05291242, -0.1431612 , -0.15733941,
        -0.15056324, -0.05988007, -0.08178931, -0.15569413, -0.09303784,
        -0.18971168,  0.0762079 , -0.02541647, -0.27134502, -0.3392682 ,
        -0.10296471, -0.27275252, -0.34078008,  0.20083308, -0.26644838,
         0.00655449, -0.05141485, -0.04261916, -0.4541363 ,  0.20023566]],

Şimdi tam modeli oluşturalım:

model = tf.keras.Sequential()
model.add(tf.keras.layers.Dense(16, activation='relu'))

tutucu11 l10n-yer
Model: "sequential"
 Layer (type)                Output Shape              Param #   
 keras_layer (KerasLayer)    (None, 50)                48190600  
 dense (Dense)               (None, 16)                816       
 dense_1 (Dense)             (None, 1)                 17        
Total params: 48,191,433
Trainable params: 48,191,433
Non-trainable params: 0

Sınıflandırıcıyı oluşturmak için katmanlar sırayla istiflenir:

  1. İlk katman bir TensorFlow Hub katmanıdır. Bu katman, bir cümleyi gömme vektörüne eşlemek için önceden eğitilmiş bir Kaydedilmiş Model kullanır. Kullanmakta olduğunuz önceden eğitilmiş metin gömme modeli ( google/nnlm-en-dim50/2 ) cümleyi belirteçlere böler, her bir belirteci gömer ve ardından gömmeyi birleştirir. Ortaya çıkan boyutlar: (num_examples, embedding_dimension) . Bu NNLM modeli için embedding_dimension 50'dir.
  2. Bu sabit uzunluktaki çıktı vektörü, 16 gizli birim ile tam bağlantılı ( Dense ) bir katmandan geçirilir.
  3. Son katman, tek bir çıkış düğümü ile yoğun bir şekilde bağlantılıdır.

Modeli derleyelim.

Kayıp fonksiyonu ve optimize edici

Bir model, eğitim için bir kayıp işlevine ve bir optimize ediciye ihtiyaç duyar. Bu bir ikili sınıflandırma problemi olduğundan ve model logit (doğrusal aktivasyona sahip tek birimli bir katman) verdiğinden, binary_crossentropy kayıp fonksiyonunu kullanacaksınız.

Bu, bir kayıp işlevi için tek seçenek değildir, örneğin, mean_squared_error . Ancak, genellikle, binary_crossentropy , olasılıklarla başa çıkmak için daha iyidir - olasılık dağılımları arasındaki veya bizim durumumuzda, gerçek-gerçek dağılımı ve tahminler arasındaki "mesafeyi" ölçer.

Daha sonra, regresyon problemlerini araştırırken (örneğin, bir evin fiyatını tahmin etmek için), ortalama kare hatası adı verilen başka bir kayıp fonksiyonunun nasıl kullanılacağını göreceksiniz.

Şimdi, modeli bir optimize edici ve bir kayıp işlevi kullanacak şekilde yapılandırın:


Modeli eğit

Modeli 512 örnekten oluşan mini gruplar halinde 10 dönem için eğitin. Bu, x_train ve y_train tensörlerindeki tüm örnekler üzerinde 10 yinelemedir. Eğitim sırasında, doğrulama setindeki 10.000 örnekte modelin kaybını ve doğruluğunu izleyin:

history = model.fit(train_data.shuffle(10000).batch(512),
tutucu14 l10n-yer
Epoch 1/10
30/30 [==============================] - 3s 59ms/step - loss: 0.6707 - accuracy: 0.5317 - val_loss: 0.6150 - val_accuracy: 0.5882
Epoch 2/10
30/30 [==============================] - 2s 57ms/step - loss: 0.5382 - accuracy: 0.7012 - val_loss: 0.4972 - val_accuracy: 0.7450
Epoch 3/10
30/30 [==============================] - 2s 56ms/step - loss: 0.3976 - accuracy: 0.8246 - val_loss: 0.4023 - val_accuracy: 0.8149
Epoch 4/10
30/30 [==============================] - 2s 61ms/step - loss: 0.2879 - accuracy: 0.8894 - val_loss: 0.3503 - val_accuracy: 0.8385
Epoch 5/10
30/30 [==============================] - 2s 59ms/step - loss: 0.2120 - accuracy: 0.9243 - val_loss: 0.3248 - val_accuracy: 0.8530
Epoch 6/10
30/30 [==============================] - 2s 54ms/step - loss: 0.1560 - accuracy: 0.9513 - val_loss: 0.3148 - val_accuracy: 0.8663
Epoch 7/10
30/30 [==============================] - 2s 55ms/step - loss: 0.1147 - accuracy: 0.9680 - val_loss: 0.3168 - val_accuracy: 0.8675
Epoch 8/10
30/30 [==============================] - 2s 56ms/step - loss: 0.0847 - accuracy: 0.9791 - val_loss: 0.3199 - val_accuracy: 0.8670
Epoch 9/10
30/30 [==============================] - 2s 54ms/step - loss: 0.0617 - accuracy: 0.9880 - val_loss: 0.3272 - val_accuracy: 0.8649
Epoch 10/10
30/30 [==============================] - 2s 57ms/step - loss: 0.0449 - accuracy: 0.9931 - val_loss: 0.3379 - val_accuracy: 0.8651

Modeli değerlendirin

Ve modelin nasıl performans gösterdiğini görelim. İki değer döndürülür. Kayıp (hatamızı temsil eden bir sayı, daha düşük değerler daha iyidir) ve doğruluk.

results = model.evaluate(test_data.batch(512), verbose=2)

for name, value in zip(model.metrics_names, results):
  print("%s: %.3f" % (name, value))
tutucu16 l10n-yer
49/49 - 2s - loss: 0.3599 - accuracy: 0.8523 - 2s/epoch - 34ms/step
loss: 0.360
accuracy: 0.852

Bu oldukça naif yaklaşım, yaklaşık %87'lik bir doğruluk sağlar. Daha gelişmiş yaklaşımlarla model %95'e yaklaşmalıdır.

daha fazla okuma

# MIT License
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# copy of this software and associated documentation files (the "Software"),
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# the rights to use, copy, modify, merge, publish, distribute, sublicense,
# and/or sell copies of the Software, and to permit persons to whom the
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