Aligning Time Series on Incomparable Spaces

Abstract

Dynamic time warping (DTW) is a useful method for aligning, comparing and combining time series, but it requires them to live in comparable spaces. In this work, we consider a setting in which time series live on different spaces without a sensible ground metric, causing DTW to become ill-defined. To alleviate this, we propose Gromov dynamic time warping (GDTW), a distance between time series on potentially incomparable spaces that avoids the comparability requirement by instead considering intra-relational geometry. We derive a Frank-Wolfe algorithm for computing it and demonstrate its effectiveness at aligning, combining and comparing time series living on incomparable spaces. We further propose a smoothed version of GDTW as a differentiable loss and assess its properties in a variety of settings, including barycentric averaging, generative modeling and imitation learning.

Publication
arXiv:2006.12648
Samuel Cohen
Samuel Cohen
PhD Student
Alexander Terenin
Alexander Terenin
PhD (10/2018-11/2021)
Marc Deisenroth
Marc Deisenroth
Google DeepMind Chair of Machine Learning and Artificial Intelligence