h2o practice

There are several machine learning libraries available in R. However, the h2o library is easy to use and offers a word2vec implementation. h2o can also be used for several other machine learning tasks. In order to use the h2o library however, you need to take additional pre-processing steps with your data. You have a dataset called left_right which contains tweets that were auto-tweeted during the 2016 US election campaign.

Instead of preparing your data for other text analysis techniques, prepare this dataset for use with the h2o library.

Cet exercice fait partie du cours

Introduction to Natural Language Processing in R

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Instructions

Import the library and initialize and h2o session.
Create an h2o object.
Tokenize the tweets which are stored in the content column.
Transform the words to lowercase and remove all stop words.

Exercice interactif pratique

Essayez cet exercice en complétant cet exemple de code.

# Initialize an h2o session
library(___)
___.init()

# Create an h2o object for left_right
h2o_object = as.___(left_right)

# Tokenize the words from the column of text in left_right
tweet_words <- h2o.___(h2o_object$___, "\\\\W+")

# Lowercase
tweet_words <- h2o.___(tweet_words)
# Remove stopwords from tweet_words
tweet_words <- tweet_words[is.na(___) || (!___ %in% stop_words$word),]
tweet_words

Modifier et exécuter le code

Cet exercice fait partie du cours

Introduction to Natural Language Processing in R

IntermédiaireNiveau de compétence

4.9+

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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: 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

Exercice en cours

Exercise 7: word2vec Exercise 8: Additional NLP analysis Exercise 9: Reviewing methods #1 Exercise 10: Review methods #2 Exercise 11: Conclusion