Mengeksplorasi korpus R

Salah satu rekan kerja Anda telah menyiapkan korpus berisi 20 dokumen yang membahas minyak mentah, bernama crude. Ini hanyalah sampel dari beberapa ribu artikel yang akan Anda terima minggu depan. Untuk bersiap menjalankan analisis teks pada dokumen-dokumen ini, Anda memutuskan untuk menelusuri konten dan metadata-nya. Ingat bahwa dalam R, sebuah VCorpus memuat meta dan content untuk setiap teks. Dalam pelajaran ini, Anda akan mengeksplorasi kedua objek tersebut.

Latihan ini adalah bagian dari kursus

Pengantar Natural Language Processing di R

Petunjuk latihan

Cetak crude dan tinjau hasilnya.
Cetak konten artikel ke-10.
Cetak ID artikel pertama dalam crude.
Dengan menggunakan for loop yang disediakan, buat sebuah vektor berisi ID dari korpus.

Latihan interaktif praktis

Cobalah latihan ini dengan menyelesaikan kode contoh berikut.

# Print out the corpus
print(___)

# Print the content of the 10th article
crude[[___]]$___

# Find the first ID
crude[[___]]$___$id

# Make a vector of IDs
ids <- c()
for(i in c(1:20)){
  ids <- append(ids, crude[[___]]$___$id)
}

Edit dan Jalankan Kode

Latihan ini adalah bagian dari kursus

Pengantar Natural Language Processing di R

SkillTag.level.intermediateSkillTag.label

4.8+

Mulai Kursus Gratis

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: Regular expression basics Exercise 2: Practicing syntax with grep Exercise 3: Exploring regular expression functions.Exercise 4: Tokenization Exercise 5: tidytext functions Exercise 6: Tokenization: sentences Exercise 7: Text cleaning basics Exercise 8: Text preprocessing: remove stop words Exercise 9: Text preprocessing: Stemming

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: Memahami korpus R Exercise 2: Mengeksplorasi korpus R

Latihan Saat Ini

Exercise 3: Membuat tibble dari korpus Exercise 4: Membuat korpus Exercise 5: Representasi bag-of-words Exercise 6: Latihan BoW Exercise 7: Contoh BoW Exercise 8: Matriks jarang (sparse matrices)Exercise 9: TFIDF Exercise 10: Perhitungan manual Exercise 11: Latihan TFIDF Exercise 12: Kemiripan Kosinus Exercise 13: Contoh kegagalan dalam analisis teks Exercise 14: Contoh cosine similarity

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