K-means clustering: primo esercizio

Questo esercizio ti aiuterà a prendere confidenza con l’uso del k-means clustering su un insieme di dati. Usiamo il dataset Comic Con per vedere come funziona il k-means clustering.

Ricorda le due fasi del k-means clustering:

Definisci i centroidi dei cluster con la funzione kmeans(). Ha due argomenti obbligatori: le osservazioni e il numero di cluster.
Assegna le etichette di cluster con la funzione vq(). Ha due argomenti obbligatori: le osservazioni e i centroidi dei cluster.

I dati sono memorizzati in un DataFrame di pandas, comic_con. x_scaled e y_scaled sono i nomi delle colonne con le coordinate X e Y standardizzate delle persone in un dato momento.

Questo esercizio fa parte del corso

Analisi di cluster in Python

Visualizza il corso

Istruzioni dell'esercizio

Importa le funzioni kmeans e vq da SciPy.
Genera i centroidi dei cluster usando la funzione kmeans() con due cluster.
Crea le etichette dei cluster utilizzando questi centroidi.

Esercizio pratico interattivo

Prova a risolvere questo esercizio completando il codice di esempio.

# Import the kmeans and vq functions
from ____.cluster.vq import ____, ____

# Generate cluster centers
cluster_centers, distortion = ____

# Assign cluster labels
comic_con['cluster_labels'], distortion_list = ____

# Plot clusters
sns.scatterplot(x='x_scaled', y='y_scaled', 
                hue='cluster_labels', data = comic_con)
plt.show()

Modifica ed esegui il codice

Questo esercizio fa parte del corso

Analisi di cluster in Python

IntermediárioNível de habilidade

4.8+

Inizia il corso gratis

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: Basi del clustering k-means Exercise 2: K-means clustering: primo esercizio

Esercizio in corso

Exercise 3: Tempo di esecuzione del clustering k-means Exercise 4: Quanti cluster?Exercise 5: Metodo del gomito su cluster distinti Exercise 6: Metodo del gomito su dati uniformi Exercise 7: Limiti del clustering k-means Exercise 8: Impatto dei semi sui cluster distinti Exercise 9: Schemi di clustering uniformi Exercise 10: FIFA 18: difensori, ritorno

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 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!