
Topological Data Analysis, or TDA is an emerging field that leverages the mathematical discipline of topology to understand complex highdimensional datasets. TDA aims to provide a comprehensive framework and a set of techniques to visualize, understand, and classify highdimensional data that might not be effectively handled by traditional statistical methods.
Topology, a major area of mathematics, studies properties of space that are preserved under continuous transformations, such as stretching and bending. This abstract branch of mathematics has found its use in data analysis due to its focus on the 'shape' of data. By studying these shapes, TDA can reveal complex structures and features in the data that other methods may overlook.
Overview
Persistent Homology
The cornerstone of TDA is Persistent Homology, a method which quantifies the shape of data and provides a robust way to classify it. It captures the topological features of data at different scales and encapsulates this information into a persistence diagram.
Mapper Algorithm
The Mapper algorithm is a tool for producing a simplified version of a dataset that still maintains the essential topological features. It divides the dataset into overlapping subsets, applies clustering to each subset, and then creates a graph where nodes represent clusters and edges represent overlap between clusters. The result is a topological "skeleton" of the data.
Reeb Graphs
Reeb graphs provide a way to understand the behavior of a realvalued function on a topological space. They are useful for summarizing multidimensional data in terms of its topological features.
Applications
TDA has been applied in a wide range of areas including biology, neuroscience, image analysis, machine learning, and material science. For instance, it has been used to identify novel subtypes of breast cancer, understand brain structure and function, and predict material properties.
