Faster Training of Neural ODEs Using Gauß-Legendre Quadrature
Alexander Norcliffe Marc Peter Deisenroth
Neural ODEs demonstrate strong performance in generative and time-series
modelling. However, training them via the adjoint method is slow compared to
discrete models due to the requirement of numerically solving ODEs. To speed
neural ODEs up, a common approach is to regularise the solutions. However, this
approach may affect the expressivity of the model; when the trajectory itself
matters, this is particularly important. In this paper, we propose an
alternative way to speed up the training of neural ODEs. The key idea is to
speed up the adjoint method by using Gau{\ss}-Legendre quadrature to solve
integrals faster than ODE-based methods while remaining memory efficient. We
also extend the idea to training SDEs using the Wong-Zakai theorem, by training
a corresponding ODE and transferring the parameters. Our approach leads to
faster training of neural ODEs, especially for large models. It also presents a
new way to train SDE-based models.