‘Density-based’ and ‘distribution-based’ approaches are two distinct techniques in cluster analysis.

graph LR
    A[Clustering Methods] --> B[Density-Based Clustering]
    A --> C[Distribution-Based Clustering]
    
    B --> D[Focuses on dense regions]
    B --> E[Robust to noise and outliers]
    B --> F[Example: DBSCAN]
    
    C --> G[Assumes data follows statistical distributions]
    C --> H[Useful for overlapping clusters]
    C --> I["Example: Gaussian Mixture Models (GMMs)"]

Density-based clustering

Density-based clustering focuses on identifying regions in a dataset where data points are densely packed together. It assumes that clusters are areas of high density separated by regions of low density. This method is particularly effective when dealing with datasets that contain clusters of irregular shapes or noise (outliers).

A well-known example of a density-based algorithm is DBSCAN (Density-Based Spatial Clustering of Applications with Noise), which we’ll explore shortly. This approach works by expanding clusters from dense regions and can efficiently ignore outliers, making it robust in real-world scenarios.

Distribution-base clustering

On the other hand, distribution-based clustering assumes that data is generated from a mixture of statistical distributions, such as Gaussian distributions. It identifies clusters by estimating the underlying probability distribution of the data and assigning points to clusters based on likelihood.

One common technique is Gaussian Mixture Models (GMMs), which use probabilistic measures to determine the probability of a data point belonging to a particular cluster. This method is particularly useful when the data follows a clear probabilistic structure or when overlapping clusters need to be analysed.

Uses

Both approaches offer unique advantages and are suited to different types of data. Density-based clustering is really useful for complex, noisy datasets, while distribution-based methods are ideal for data with well-defined probabilistic patterns.


Next reading:

Hard vs. Soft Clustering