Data Science and Machine Learning (Theory and Projects) A to Z - Feature Extraction: PCA Implementation

The video tutorial covers the implementation of Principal Component Analysis (PCA) using Numpy. It begins with setting up the environment and importing necessary libraries. The instructor then loads a face dataset and explains how to prepare the data by calculating the mean vector and covariance matrix. The tutorial proceeds with eigen decomposition to find eigenvalues and eigenvectors, which are used for dimensionality reduction. The instructor demonstrates how to reconstruct data from reduced dimensions and visualizes eigenfaces. The video concludes with a discussion on choosing the optimal number of dimensions (K) to retain most of the data's information.

What is the impact of reducing dimensions on the reconstruction of data?

Discuss the concept of eigenfaces and their significance in PCA.

What are the potential criticisms of PCA as mentioned in the text?

Summarize the overall implementation process of PCA as described in the text.