Mean-Shift Clustering

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Mean shift clustering is a sliding-window-based algorithm that attempts to find dense areas of data points. It is a centroid-based algorithm meaning that the goal is to locate the center points of each group/class, which works by updating candidates for center points to be the mean of the points within the sliding-window. These candidate windows are then filtered in a post-processing stage to eliminate near-duplicates, forming the final set of center points and their corresponding groups. The 5 Clustering Algorithms Data Scientists Need to Know | Towards Data Science

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An illustration of the entire process from end-to-end with all of the sliding windows is show below. Each black dot represents the centroid of a sliding window and each gray dot is a data point.

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In contrast to K-means clustering there is no need to select the number of clusters as mean-shift automatically discovers this. That’s a massive advantage. The fact that the cluster centers converge towards the points of maximum density is also quite desirable as it is quite intuitive to understand and fits well in a naturally data-driven sense. The drawback is that the selection of the window size/radius “r” can be non-trivial.