# Lesson Archives

1. ## Introduction to GGPlot2

This article presents the basics of ggplot2. The key ggplot graphic functions are presented. You will learn how to build a ggplot piece by piece, as well as, how to customize and export the plot
2. ## cmeans() R function: Compute Fuzzy clustering

This article describes how to compute the fuzzy clustering using the function cmeans() [in e1071 R package]
3. ## Fuzzy C-Means Clustering Algorithm

This current article presents the fuzzy c-means clustering algorithm.
4. ## DBSCAN: Density-Based Clustering Essentials

The density-based clustering (DBSCAN is a partitioning method that has been introduced in Ester et al. (1996). It can find out clusters of different shapes and sizes from data containing noise and outliers. In this chapter, we’ll describe the DBSCAN algorithm and demonstrate how to compute DBSCAN using the fpc R package.
5. ## Model Based Clustering Essentials

In model-based clustering, the data are viewed as coming from a distribution that is mixture of two ore more clusters. It finds best fit of models to data and estimates the number of clusters. In this chapter, we illustrate model-based clustering using the R package mclust.
6. ## Fuzzy Clustering Essentials

Fuzzy clustering is also known as soft method. Standard clustering (K-means, PAM) approaches produce partitions, in which each observation belongs to only one cluster. This is known as hard clustering. In Fuzzy clustering, items can be a member of more than one cluster. Each item has a set of membership coefficients corresponding to the degree of being in a given cluster. In this article, we’ll describe how to compute fuzzy clustering using the R software.
7. ## Hierarchical K-Means Clustering: Optimize Clusters

The hierarchical k-means clustering is an hybrid approach for improving k-means results. In this article, you will learn how to compute hierarchical k-means clustering in R
8. ## Computing P-value for Hierarchical Clustering

This article describes the R package pvclust, which uses bootstrap resampling techniques to compute p-value for each hierarchical clusters.
9. ## Choosing the Best Clustering Algorithms

In this article, we’ll start by describing the different measures in the clValid R package for comparing clustering algorithms. Next, we’ll present the function clValid(). Finally, we’ll provide R scripts for validating clustering results and comparing clustering algorithms.
10. ## Cluster Validation Statistics: Must Know Methods

In this article, we start by describing the different methods for clustering validation. Next, we'll demonstrate how to compare the quality of clustering results obtained with different clustering algorithms. Finally, we'll provide R scripts for validating clustering results.