手法を比較

	スペクトラルクラスタリング	K-means クラスタリング
分野	機械学習	機械学習
系統	Machine learning	Machine learning
提唱年	2002	1967 (formalized 1982)
提唱者	Ng, A. Y.; Jordan, M. I.; Weiss, Y.	MacQueen, J. B.; Lloyd, S. P.
種類	Graph-based clustering (spectral method)	Partitional clustering
原典	Ng, A. Y., Jordan, M. I., & Weiss, Y. (2002). On Spectral Clustering: Analysis and an Algorithm. Advances in Neural Information Processing Systems, 14, 849–856.	Lloyd, S. P. (1982). Least squares quantization in PCM. IEEE Transactions on Information Theory, 28(2), 129–137.
別名	NJW spectral clustering, graph Laplacian clustering, normalized spectral clustering, spectral graph clustering	k-means clustering, Lloyd's algorithm, k-means partitioning, hard k-means
関連	5	4
概要	Spectral Clustering is a graph-based unsupervised learning algorithm, formalized by Ng, Jordan, and Weiss in 2002, that maps data points into a low-dimensional eigenspace derived from the similarity graph's Laplacian before applying k-means. This spectral embedding makes it possible to recover clusters of arbitrary shape — rings, crescents, interleaved spirals — that Euclidean distance-based methods consistently fail to separate.	K-means is a classic unsupervised partitional clustering algorithm that divides a dataset into K non-overlapping groups by iteratively assigning each observation to its nearest centroid and updating centroids as the mean of their assigned points. It is one of the most widely used exploratory tools in machine learning and data analysis.