Leland McInnes
Also known as L. McInnes
Leland McInnes is a mathematician and data scientist whose machine-learning work includes UMAP for dimension reduction and HDBSCAN clustering. He studied pure mathematics after starting in physics, worked at a casino analytics company in 2000, and later applied topology to unsupervised learning at the Tutte Institute. With John Healy and James Melville, he developed UMAP as a scalable method grounded in Riemannian geometry and algebraic topology, and he and Healy refined DBSCAN into HDBSCAN. As of October 2026, he is a research mathematician and data scientist at the Tutte Institute.
- Now at
- Tutte Institute for Mathematics and Computing
Timeline
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2000
Mathematics and casino analytics
He starts in physics before switching to pure mathematics and earns a master's in algorithms in algebraic geometry. In 2000, he works at a company specializing in casino analytics and explores data visualization with self-organizing maps.
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February 2018
UMAP for dimension reduction
In February 2018, he posts the UMAP paper with John Healy and James Melville. Their scalable dimension-reduction technique is grounded in Riemannian geometry and algebraic topology and can serve as a general-purpose method for machine learning.
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July 2018
Research at the Tutte Institute
In July 2018, he is a research mathematician at the Tutte Institute and applies topological techniques to unsupervised learning. He holds a Ph.D. in profinite Lie rings.
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By August 2018
Refining DBSCAN with HDBSCAN
By August 2018, he and John Healy refine DBSCAN into HDBSCAN. Their high-performance Python implementation makes the algorithm orders of magnitude more efficient and becomes its de facto reference implementation.
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As of October 2026
Research mathematician at Tutte
As of October 2026, he is a research mathematician and data scientist at the Tutte Institute for Mathematics and Computing. He gives a keynote talk on high-dimensional data at the Workshop on Visualization for AI Explainability.
Sources and credits
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- Smuggled Gold and Untrustworthy Intuition — with Leland McInnes :: Posit Open Source
- UMAP: Uniform Manifold Approximation and Projection for Dimension Reduction
- UMAP: Uniform Manifold Approximation and Projection for Dimension Reduction
- Hierarchical Density-Based Spatial Clustering of Applications with Noise (HDBSCAN)
- 9th Workshop on Visualization for AI Explainability