Metin ön işleme: Kök bulma (Stemming)

Metin analizinde, kelimelerin kökleri çoğu zaman eklerinden daha önemlidir. Animal Farm kitabı açıkça hayvanlar hakkında. Ancak kitapta animal's 248 kez, animal ise 107 kez geçiyor olması analizinde pek yardımcı olmayabilir.

tidy_animal_farm, Animal Farm'daki kelimelerin, belirteçlerine ayrılmış ve durak kelimeler çıkarılmış bir tibble'ını içerir. Bir sonraki adım kelimeleri köklerine indirgemek (stem) ve sonuçları incelemek.

Bu egzersiz

R ile Doğal Dil İşlemeye Giriş

kursunun bir parçasıdır

Kursu Görüntüle

Egzersiz talimatları

tidy_animal_farm içindeki kelimeleri köklerine indirmek için dplyr ve SnowballC kullan.
Eski kelime sıklıklarını tidy_animal_farm'dan yazdır.
Yeni kelime sıklıklarını stemmed_animal_farm'dan yazdır.

Uygulamalı interaktif egzersiz

Bu örnek kodu tamamlayarak bu egzersizi bitirin.

# Perform stemming on tidy_animal_farm
stemmed_animal_farm <- tidy_animal_farm %>%
  ___(word = ___(___))

# Print the old word frequencies 
___ %>%
  ___(word, sort = ___)

# Print the new word frequencies
___ %>%
  ___(word, sort = ___)

Kodu Düzenle ve Çalıştır

Bu egzersiz

R ile Doğal Dil İşlemeye Giriş

kursunun bir parçasıdır

IntermediárioNível de habilidade

4.8+

Kursa Ücretsiz Başlayın

Chapter 1 of Introduction to Natural Langauge Processing prepares you for running your first analysis on text. You will explore regular expressions and tokenization, two of the most common components of most analysis tasks. With regular expressions, you can search for any pattern you can think of, and with tokenization, you can prepare and clean text for more sophisticated analysis. This chapter is necessary for tackling the techniques we will learn in the remaining chapters of this course.

Exercise 1: Düzenli ifadelerin temelleri Exercise 2: grep ile sözdizimi pratiği Exercise 3: Düzenli ifade fonksiyonlarını keşfetme.Exercise 4: Tokenizasyon Exercise 5: tidytext fonksiyonları Exercise 6: Tokenizasyon: cümleler Exercise 7: Metin temizliğinin temelleri Exercise 8: Metin önişleme: durak sözcükleri kaldır Exercise 9: Metin ön işleme: Kök bulma (Stemming)

Geçerli Egzersiz

In this chapter, you will learn the most common and studied ways to analyze text. You will look at creating a text corpus, expanding a bag-of-words representation into a TFIDF matrix, and use cosine-similarity metrics to determine how similar two pieces of text are to each other. You build on your foundations for practicing NLP before you dive into applications of NLP in chapters 3 and 4.

Exercise 1: Understanding an R corpus Exercise 2: Explore an R corpus Exercise 3: Creating a tibble from a corpus Exercise 4: Creating a corpus Exercise 5: The bag-of-words representation Exercise 6: Practice BoW Exercise 7: BoW Example Exercise 8: Sparse matrices Exercise 9: The TFIDF Exercise 10: Manual calculations Exercise 11: TFIDF Practice Exercise 12: Cosine Similarity Exercise 13: An example of failing at text analysis Exercise 14: Cosine similarity example

Chapter 3 focuses on two common text analysis approaches, classification modeling, and topic modeling. If you are working on text analysis projects, you will inevitably use one or both of these methods. This chapter teaches you how to perform both techniques and provides insight into how to approach these techniques from a practical point of you.

Exercise 1: Preparing text for modeling Exercise 2: Data preparation Exercise 3: Removing sparse terms Exercise 4: Classification modeling Exercise 5: Classification modeling example Exercise 6: Confusion matrices Exercise 7: TFIDF tibble vs dtm Exercise 8: Introduction to topic modeling Exercise 9: LDA practice Exercise 10: Assigning topics to documents Exercise 11: LDA in practice Exercise 12: Testing perplexity Exercise 13: Reviewing LDA results

In chapter 4 we cover two staples of natural language processing, sentiment analysis, and word embeddings. These are two analysis techniques that are a must for anyone learning the fundamentals of text analysis. Furthermore, you will briefly learn about BERT, part-of-speech tagging, and named entity recognition. Almost 15 different analysis techniques were covered in this course, so chapter 4 ends by recapping all of the great techniques you will learn about in this course.

Exercise 1: Sentiment analysis Exercise 2: tidytext lexicons Exercise 3: Sentiment scores Exercise 4: Sentiment and emotion Exercise 5: Word embeddings Exercise 6: h2o practice Exercise 7: word2vec Exercise 8: Additional NLP analysis Exercise 9: Reviewing methods #1 Exercise 10: Review methods #2 Exercise 11: Conclusion