Abstract:
According to the manifold hypothesis, high-dimensional data can be
viewed and meaningfully represented as a lower-dimensional manifold
embedded in a higher dimensional feature space. Manifold learning is
a part of machine learning where an intrinsic data representation is
uncovered based on the manifold hypothesis.
Many manifold learning algorithms were developed. The one called
Grassmann & Stiefel eigenmaps (GSE) has been considered in the
paper. One of the GSE subproblems is tangent space alignment. The
original solution to this problem has been formulated as a
generalized eigenvalue problem. In this formulation, it is plagued
with numerical instability, resulting in suboptimal solutions to the
subproblem and manifold reconstruction problem in general.
We have proposed an iterative algorithm to directly solve the
tangent spaces alignment problem. As a result, we have obtained a
significant gain in algorithm efficiency and time complexity. We
have compared the performance of our method on various model data
sets to show that our solution is on par with the approach to vector
fields alignment formulated as an optimization on the Stiefel group.
Keywords:manifold learning, dimensionality reduction, numerical optimization, vector field estimation.