Steinbeis-Transferzentrum Data Analytics und Predictive Modelling
VisualApp

K-Nearest Neighbors 3D

The k-Nearest Neighbours algorithm in three dimensions: two classes of data points in 3D space, new points are classified live with their k nearest neighbours shown connected. The scene can be freely rotated and zoomed.

About the App

The app shows how the kNN algorithm works in a three-dimensional feature space. Two classes of training data — blue and red — are distributed as spheres in space. New, initially white data points appear one by one and are classified: first their k=5 nearest neighbours are shown connected by lines, then the point takes on the colour of the majority class.

The animation illustrates the fundamental principle of kNN: classification by similarity in feature space — without any training, solely through distances.

What can I do?

Rotate the scene by clicking and dragging. Zoom with the scroll wheel. The classification of new data points runs automatically — observe how points in the border region between the two classes are classified with more uncertainty than points deep inside a class.

Interested in AI visualisations for teaching?

The VisualApps are created as a teaching and transfer project at Reutlingen University and are used in corporate training and talks.

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