
Explore unsupervised learning, where there is no dependent variable, and contrast it with supervised learning. Learn three methods—k means method, hierarchical cluster analysis, and principal component analysis.
Explore how the k-means unsupervised learning method clusters observations by proximity using distance metrics, iteratively updating random centers to minimize the sum of squared errors within clusters.
Apply k-means clustering to the USA arrests dataset, using min-max scaling, standardization, and optional PCA, then compare cluster centers and inertia to determine the optimal number of clusters.
Determine the optimal number of clusters in k-means by the elbow method, using SSD and distortion scores, testing k from 1 to 30, and balancing with business knowledge.
Fit the final k-means model with elbow-determined five clusters, assign labels to the data frame, and export the cluster assignments to clusters.csv.
Explore hierarchical clustering methods, using agglomerative and divisive approaches to form clusters based on similarities, from leaves up or from one cluster down, with lines defining levels.
Apply hierarchical clustering to the USA arrest data by standardizing variables and using agglomerative linkage with a dendrogram to determine the optimal number of clusters.
Explore determining the number of clusters from dendrograms by drawing threshold lines and comparing hierarchical clustering with K-means, then assign cluster labels with agglomerative methods.
Apply principal component analysis to reduce multivariate data to fewer uncorrelated components with minimal information loss. Rely on eigenvalues to rank variance and guide dimension reduction, visualization, and noise reduction.
Apply principal component analysis to the hitter's numerical data to reduce 16 variables to 2–3 components and assess success with explained variance ratios and the elbow method.
Learn to visualize high-dimensional data with PCA, reducing to two components, and graphically separate classes using breast cancer and iris datasets through a general PCA visualization function.
Use principal component regression to reduce 16 numeric variables to three uncorrelated components. Then build and evaluate a regression model with cross-validation, addressing multicollinearity.
Welcome to the seventh chapter of Miuul's Ultimate ML Bootcamp—a comprehensive series designed to elevate your expertise in machine learning with a focus on unsupervised learning techniques. In this chapter, "Unsupervised Learning," we will dive into the world of machine learning where the data lacks predefined labels, uncovering the hidden structures and patterns that emerge from raw data.
This chapter begins with an Introduction to Unsupervised Learning, setting the stage by exploring the key concepts and importance of this approach in the context of data analysis. You will then move on to one of the most widely used clustering techniques, K-Means, starting with a theoretical foundation and progressing through multiple practical applications to illustrate its effectiveness in real-world scenarios.
Next, we'll shift our focus to Hierarchical Clustering, another powerful method for discovering structure within data. You will learn the mechanics of this technique and apply it through hands-on sessions that demonstrate its utility across various datasets.
As we continue, we'll introduce you to Principal Component Analysis (PCA), a dimensionality reduction technique that simplifies data while preserving its essential characteristics. The chapter will cover both the theory and practical applications of PCA, along with visualization techniques to help interpret and understand the transformed data.
Finally, the chapter concludes with Principal Component Regression (PCR), combining the strengths of PCA and regression analysis to improve predictive modeling in high-dimensional spaces.
Throughout this chapter, you will gain a deep understanding of the principles and practicalities of unsupervised learning methods. You will learn not only how to implement these techniques but also how to interpret their results to make informed decisions. By the end, you will be equipped with a solid foundation in unsupervised learning, enabling you to uncover patterns and insights from complex datasets with confidence.
We are excited to accompany you on this journey into the fascinating domain of unsupervised learning, where you will learn to find order in chaos and extract meaningful insights from unlabeled data. Let's dive in and unlock new dimensions of your analytical capabilities!