Title
A Multiscale Semi-Smooth Newton Method for Optimal Transport
Abstract
Our goal is to solve the large-scale linear programming (LP) formulation of Optimal Transport (OT) problems efficiently. Our key observations are: (i) the primal solutions of the LP problems are theoretically very sparse; (ii) the cost function is usually equipped with good geometric properties. The former motivates us to eliminate the majority of the variables, while the latter easily enables us to exploit a hierarchical multiscale structure. Each level in this structure corresponds to a standard OT problem, whose solution can be obtained by solving a series of restricted OT problems by fixing most of the primal variables to zeros and using the semi-smooth Newton method. We improve the performance of computing the semi-smooth Newton direction by forming and solving a much smaller symmetric positive-definite system whose matrix can be written explicitly according to the sparsity patterns. Extensive numerical experiments show that our algorithm is quite efficient compared to the state-of-the-art methods such as a multiscale implementation of the CPLEX’s Networkflow algorithm and the SparseSinkhorn method, due to its ability to solve problems at a much larger scale and obtain the optimal solution in less time.
Year
DOI
Venue
2022
10.1007/s10915-022-01813-y
Journal of Scientific Computing
Keywords
DocType
Volume
Optimal transport, Sparsity, Semi-smooth Newton method, Multiscale structure, 15A03, 65F10, 65K05, 90C05
Journal
91
Issue
ISSN
Citations 
2
0885-7474
0
PageRank 
References 
Authors
0.34
9
3
Name
Order
Citations
PageRank
Yiyang Liu100.34
Zaiwen Wen293440.20
Wotao Yin35038243.92