K-means clustering is a widely used unsupervised machine learning algorithm designed to partition a dataset into K distinct, non-overlapping clusters. The objective is to minimize the variance within each cluster while maximizing the variance between clusters. The algorithm works through the following steps:
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Initialization: Randomly choose K initial centroids (cluster centers).
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Assignment: Assign each data point to the nearest centroid based on a distance metric (usually Euclidean distance).
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Update: Recalculate the centroids by computing the mean of all points assigned to each cluster.
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Repeat: Repeat the assignment and update steps until convergence, i.e., when the centroids no longer change significantly.
Limitations of K-means:
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Sensitive to Initialization: The algorithm’s performance can vary based on the initial selection of centroids, which may lead to suboptimal clustering.
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Fixed Number of Clusters (K): The number of clusters (K) must be specified in advance, and determining the optimal K can be difficult.
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Non-Spherical Clusters: K-means assumes spherical clusters with roughly equal sizes, making it ineffective for clusters with irregular shapes or differing densities.
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Sensitive to Outliers: Outliers can significantly affect the placement of centroids and lead to poor clustering results.
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Scalability: While efficient, K-means may struggle with very large datasets, especially in high-dimensional spaces.
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