Top terms in movie clusters

Now that you have created a sparse matrix, generate cluster centers and print the top three terms in each cluster. Use the .todense() method to convert the sparse matrix, tfidf_matrix to a normal matrix for the kmeans() function to process. Then, use the .get_feature_names() method to get a list of terms in the tfidf_vectorizer object. The zip() function in Python joins two lists.

The tfidf_vectorizer object and sparse matrix, tfidf_matrix, from the previous have been retained in this exercise. kmeans has been imported from SciPy.

With a higher number of data points, the clusters formed would be defined more clearly. However, this requires some computational power, making it difficult to accomplish in an exercise here.

Cet exercice fait partie du cours

Cluster Analysis in Python

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Instructions

Generate cluster centers through the kmeans() function.
Generate a list of terms from the tfidf_vectorizer object.
Print top 3 terms of each cluster.

Exercice interactif pratique

Essayez cet exercice en complétant cet exemple de code.

num_clusters = 2

# Generate cluster centers through the kmeans function
cluster_centers, distortion = ____

# Generate terms from the tfidf_vectorizer object
terms = tfidf_vectorizer.____()

for i in range(num_clusters):
    # Sort the terms and print top 3 terms
    center_terms = dict(zip(____, ____))
    sorted_terms = sorted(____, key=center_terms.get, reverse=True)
    print(____)

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Cet exercice fait partie du cours

Cluster Analysis in Python

IntermédiaireNiveau de compétence

4.8+

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Before you are ready to classify news articles, you need to be introduced to the basics of clustering. This chapter familiarizes you with a class of machine learning algorithms called unsupervised learning and then introduces you to clustering, one of the popular unsupervised learning algorithms. You will know about two popular clustering techniques - hierarchical clustering and k-means clustering. The chapter concludes with basic pre-processing steps before you start clustering data.

Exercise 1: Unsupervised learning: basics Exercise 2: Unsupervised learning in real world Exercise 3: Pokémon sightings Exercise 4: Basics of cluster analysis Exercise 5: Pokémon sightings: hierarchical clustering Exercise 6: Pokémon sightings: k-means clustering Exercise 7: Data preparation for cluster analysis Exercise 8: Normalize basic list data Exercise 9: Visualize normalized data Exercise 10: Normalization of small numbers Exercise 11: FIFA 18: Normalize data

This chapter focuses on a popular clustering algorithm - hierarchical clustering - and its implementation in SciPy. In addition to the procedure to perform hierarchical clustering, it attempts to help you answer an important question - how many clusters are present in your data? The chapter concludes with a discussion on the limitations of hierarchical clustering and discusses considerations while using hierarchical clustering.

Exercise 1: Basics of hierarchical clustering Exercise 2: Hierarchical clustering: ward method Exercise 3: Hierarchical clustering: single method Exercise 4: Hierarchical clustering: complete method Exercise 5: Visualize clusters Exercise 6: Visualize clusters with matplotlib Exercise 7: Visualize clusters with seaborn Exercise 8: How many clusters?Exercise 9: Create a dendrogram Exercise 10: How many clusters in comic con data?Exercise 11: Limitations of hierarchical clustering Exercise 12: Timing run of hierarchical clustering Exercise 13: FIFA 18: exploring defenders

This chapter introduces a different clustering algorithm - k-means clustering - and its implementation in SciPy. K-means clustering overcomes the biggest drawback of hierarchical clustering that was discussed in the last chapter. As dendrograms are specific to hierarchical clustering, this chapter discusses one method to find the number of clusters before running k-means clustering. The chapter concludes with a discussion on the limitations of k-means clustering and discusses considerations while using this algorithm.

Exercise 1: Basics of k-means clustering Exercise 2: K-means clustering: first exercise Exercise 3: Runtime of k-means clustering Exercise 4: How many clusters?Exercise 5: Elbow method on distinct clusters Exercise 6: Elbow method on uniform data Exercise 7: Limitations of k-means clustering Exercise 8: Impact of seeds on distinct clusters Exercise 9: Uniform clustering patterns Exercise 10: FIFA 18: defenders revisited

Now that you are familiar with two of the most popular clustering techniques, this chapter helps you apply this knowledge to real-world problems. The chapter first discusses the process of finding dominant colors in an image, before moving on to the problem discussed in the introduction - clustering of news articles. The chapter concludes with a discussion on clustering with multiple variables, which makes it difficult to visualize all the data.

Exercise 1: Dominant colors in images Exercise 2: Extract RGB values from image Exercise 3: How many dominant colors?Exercise 4: Display dominant colors Exercise 5: Document clustering Exercise 6: TF-IDF of movie plots Exercise 7: Top terms in movie clusters

Exercice en cours

Exercise 8: Clustering with multiple features Exercise 9: Clustering with many features Exercise 10: Basic checks on clusters Exercise 11: FIFA 18: what makes a complete player?Exercise 12: Farewell!