NMF-features van de Wikipedia-artikelen

Nu ga je de NMF-features verkennen die je in de vorige oefening hebt gemaakt. Een oplossing van de vorige oefening is alvast ingeladen, dus de array nmf_features is beschikbaar. Ook is er een lijst titles met de titel van elk Wikipedia-artikel.

Let bij het onderzoeken van de features op dat voor beide acteurs NMF-feature 3 veruit de hoogste waarde heeft. Dit betekent dat beide artikelen vooral worden gereconstrueerd met de 3e NMF-component. In de volgende video zie je waarom: NMF-componenten stellen onderwerpen voor (bijvoorbeeld acteren!).

Deze oefening maakt deel uit van de cursus

Unsupervised Learning in Python

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Oefeninstructies

Importeer pandas als pd.
Maak een DataFrame df van nmf_features met pd.DataFrame(). Zet de index op titles met index=titles.
Gebruik de .loc[]-accessor van df om de rij met titel 'Anne Hathaway' te selecteren, en print het resultaat. Dit zijn de NMF-features voor het artikel over de actrice Anne Hathaway.
Herhaal de vorige stap voor 'Denzel Washington' (ook een acteur).

Praktische interactieve oefening

Probeer deze oefening eens door deze voorbeeldcode in te vullen.

# Import pandas
____

# Create a pandas DataFrame: df
df = ____

# Print the row for 'Anne Hathaway'
print(____)

# Print the row for 'Denzel Washington'
print(____)

Code bewerken en uitvoeren

Deze oefening maakt deel uit van de cursus

Unsupervised Learning in Python

SkillTag.level.intermediateSkillTag.label

4.8+

Begin de cursus gratis

Learn how to discover the underlying groups (or "clusters") in a dataset. By the end of this chapter, you'll be clustering companies using their stock market prices, and distinguishing different species by clustering their measurements.

Exercise 1: Unsupervised Learning Exercise 2: How many clusters?Exercise 3: Clustering 2D points Exercise 4: Inspect your clustering Exercise 5: Evaluating a clustering Exercise 6: How many clusters of grain?Exercise 7: Evaluating the grain clustering Exercise 8: Transforming features for better clusterings Exercise 9: Scaling fish data for clustering Exercise 10: Clustering the fish data Exercise 11: Clustering stocks using KMeans Exercise 12: Which stocks move together?

In this chapter, you'll learn about two unsupervised learning techniques for data visualization, hierarchical clustering and t-SNE. Hierarchical clustering merges the data samples into ever-coarser clusters, yielding a tree visualization of the resulting cluster hierarchy. t-SNE maps the data samples into 2d space so that the proximity of the samples to one another can be visualized.

Exercise 1: Visualizing hierarchies Exercise 2: How many merges?Exercise 3: Hierarchical clustering of the grain data Exercise 4: Hierarchies of stocks Exercise 5: Cluster labels in hierarchical clustering Exercise 6: Which clusters are closest?Exercise 7: Different linkage, different hierarchical clustering!Exercise 8: Intermediate clusterings Exercise 9: Extracting the cluster labels Exercise 10: t-SNE for 2-dimensional maps Exercise 11: t-SNE visualization of grain dataset Exercise 12: A t-SNE map of the stock market

Dimension reduction summarizes a dataset using its common occuring patterns. In this chapter, you'll learn about the most fundamental of dimension reduction techniques, "Principal Component Analysis" ("PCA"). PCA is often used before supervised learning to improve model performance and generalization. It can also be useful for unsupervised learning. For example, you'll employ a variant of PCA will allow you to cluster Wikipedia articles by their content!

Exercise 1: Visualizing the PCA transformation Exercise 2: Correlated data in nature Exercise 3: Decorrelating the grain measurements with PCA Exercise 4: Principal components Exercise 5: Intrinsic dimension Exercise 6: The first principal component Exercise 7: Variance of the PCA features Exercise 8: Intrinsic dimension of the fish data Exercise 9: Dimension reduction with PCA Exercise 10: Dimension reduction of the fish measurements Exercise 11: A tf-idf word-frequency array Exercise 12: Clustering Wikipedia part I Exercise 13: Clustering Wikipedia part II

In this chapter, you'll learn about a dimension reduction technique called "Non-negative matrix factorization" ("NMF") that expresses samples as combinations of interpretable parts. For example, it expresses documents as combinations of topics, and images in terms of commonly occurring visual patterns. You'll also learn to use NMF to build recommender systems that can find you similar articles to read, or musical artists that match your listening history!

Exercise 1: Niet-negatieve matrixfactorisatie (NMF)Exercise 2: Niet-negatieve data Exercise 3: NMF toegepast op Wikipedia-artikelen Exercise 4: NMF-features van de Wikipedia-artikelen

Huidige oefening

Exercise 5: NMF reconstrueert steekproeven Exercise 6: NMF leert interpreteerbare onderdelen Exercise 7: NMF leert onderwerpen van documenten Exercise 8: Verken de LED-cijferdataset Exercise 9: NMF leert de delen van afbeeldingen Exercise 10: PCA leert geen delen Exercise 11: Aanbevelingssystemen bouwen met NMF Exercise 12: Welke artikelen lijken op 'Cristiano Ronaldo'?Exercise 13: Muziekaartiesten aanbevelen deel I Exercise 14: Muziekartiesten aanbevelen, deel II Exercise 15: Tot slot