PCA Beyond The Concept of Manifolds: Principal Trees, Metro Maps, and Elastic Cubic Complexes

Recommended citation: Gorban AN, Sumner NR, Zinovyev A. PCA Beyond The Concept of Manifolds: Principal Trees, Metro Maps, and Elastic Cubic Complexes. In Principal Manifolds for Data Visualization and Dimension Reduction, Lecture Notes in Computational Science and Engineering 58, Springer, Berlin - Heidelberg, 2008, 219-237 https://arxiv.org/abs/0801.0176