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In data mining, k-means++ [1] [2] is an algorithm for choosing the initial values (or "seeds") for the k-means clustering algorithm. It was proposed in 2007 by David Arthur and Sergei Vassilvitskii, as an approximation algorithm for the NP-hard k-means problem—a way of avoiding the sometimes poor clusterings found by the standard k-means algorithm.
k-means clustering is a popular algorithm used for partitioning data into k clusters, where each cluster is represented by its centroid. However, the pure k -means algorithm is not very flexible, and as such is of limited use (except for when vector quantization as above is actually the desired use case).
In statistics and data mining, X-means clustering is a variation of k-means clustering that refines cluster assignments by repeatedly attempting subdivision, and keeping the best resulting splits, until a criterion such as the Akaike information criterion (AIC) or Bayesian information criterion (BIC) is reached. [5]
Centroid model s: for example, the k-means algorithm represents each cluster by a single mean vector. Distribution model s: clusters are modeled using statistical distributions, such as multivariate normal distributions used by the expectation-maximization algorithm.
In applied mathematics, k-SVD is a dictionary learning algorithm for creating a dictionary for sparse representations, via a singular value decomposition approach. k-SVD is a generalization of the k-means clustering method, and it works by iteratively alternating between sparse coding the input data based on the current dictionary, and updating the atoms in the dictionary to better fit the data.
{{Information |Description=This image is part of a series of images which give an example of the operation of the k-means algorithm. This is the first image of four. |Source=self-made |Date=July 26, 2007 |Author= Weston.pace}} 19:09, 26 July 2007: 240 × 360 (7 KB) Weston.pace~commonswiki
Clustering Density-Based Clustering; Fuzzy C-Means Clustering; Hierarchical Clustering; Model-based clustering; Neighborhood-based Clustering (i.e., K-Means Clustering, K-Medians clustering, K-Medoids clustering) Random Forest Clustering; Meta Analysis: Synthesise evidence across multiple studies. Includes techniques for fixed and random ...
Each group is represented by its centroid point, as in k-means and some other clustering algorithms. In simpler terms, vector quantization chooses a set of points to represent a larger set of points. The density matching property of vector quantization is powerful, especially for identifying the density of large and high-dimensional data.