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Hierarchical Clustering. Dr. Bernard Chen Assistant Professor. Outline. Hierarchical Clustering Hybrid Hierarchical Kmeans clustering DBscan. Hierarchical Clustering. Venn Diagram of Clustered Data. Dendrogram.
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Hierarchical Clustering Dr. Bernard Chen Assistant Professor
Outline • Hierarchical Clustering • Hybrid Hierarchical Kmeans clustering • DBscan
Hierarchical Clustering Venn Diagram of Clustered Data Dendrogram From http://www.stat.unc.edu/postscript/papers/marron/Stat321FDA/RimaIzempresentation.ppt
Nearest Neighbor, Level 2, k = 1 clusters. From http://www.stat.unc.edu/postscript/papers/marron/Stat321FDA/RimaIzempresentation.ppt
Typical Alternatives to Calculate the Distance between Clusters • Single link: smallest distance between an element in one cluster and an element in the other, i.e., dis(Ki, Kj) = min(tip, tjq) • Complete link: largest distance between an element in one cluster and an element in the other, i.e., dis(Ki, Kj) = max(tip, tjq) • Average: avg distance between an element in one cluster and an element in the other, i.e., dis(Ki, Kj) = avg(tip, tjq)
Functional significant gene clusters Two-way clustering Sample clusters Gene clusters
Outline • Hierarchical Clustering • Hybrid Hierarchical Kmeans clustering • DBscan
Motivation • Among clustering algorithms, Hierarchical and K-means clustering are the two most popular and classic methods. However, both have their innate disadvantages. • K-means clustering requires a specified number of clusters in advance and chooses initial centroids randomly; in other words, you don’t know how to start • Hierarchical clustering is hard to find a place to cut
Hybrid Hierarchical K-means Clustering (HHK) Algorithm • The brief idea is we cluster around half data through Hierarchical clustering and succeed by K-means for the remaining • In order to generate super-rules, we let Hierarchical terminate when it generates the largest number of clusters
Hybrid Hierarchical K-means Clustering (HHK) Algorithm Example
Hybrid Hierarchical K-means Clustering (HHK) Algorithm Example
Hybrid Hierarchical K-means Clustering (HHK) Algorithm Example
Hybrid Hierarchical K-means Clustering (HHK) Algorithm Example
Hybrid Hierarchical K-means Clustering (HHK) Algorithm Example
Hybrid Hierarchical K-means Clustering (HHK) Algorithm Example
Hybrid Hierarchical K-means Clustering (HHK) Algorithm Example