Implementing Principal Component Analysis (PCA) in R
“Give me six hours to chop down a tree and I will spend the first four sharpening the axe.” – Abraham Lincoln This timeless quote applies beautifully to machine learning and data science. The success of any predictive model often depends less on the choice of algorithm and more on the effort spent in data preprocessing, cleaning, and feature engineering. One key part of feature engineering is deciding which features actually add value. This is where dimensionality reduction becomes essential, and among the various techniques available, Principal Component Analysis (PCA) stands out as one of the most widely used. In this article, we’ll explore PCA step by step—starting from the curse of dimensionality to conceptual foundations, and finally its application in R using the well-known Iris dataset. Table of Contents Lifting the Curse with PCA The Curse of Dimensionality Explained Insights from Shlens’ PCA Paper Conceptual Background of PCA Step-by-Step Implementation in R Interpreting PCA...