GradVis: Visualization and Second Order Analysis of Optimization Surfaces during the Training of Deep Neural Networks
This provides a practical tool for researchers and practitioners to gain insights into optimization surfaces in deep learning, though it is incremental as it builds on existing visualization methods.
The paper tackles the problem of high computational cost in visualizing and analyzing deep neural network loss landscapes by introducing GradVis, an open-source toolbox that enables efficient 2D/3D projections and second-order gradient analysis for large networks through more efficient formulations and parallelization.
Current training methods for deep neural networks boil down to very high dimensional and non-convex optimization problems which are usually solved by a wide range of stochastic gradient descent methods. While these approaches tend to work in practice, there are still many gaps in the theoretical understanding of key aspects like convergence and generalization guarantees, which are induced by the properties of the optimization surface (loss landscape). In order to gain deeper insights, a number of recent publications proposed methods to visualize and analyze the optimization surfaces. However, the computational cost of these methods are very high, making it hardly possible to use them on larger networks. In this paper, we present the GradVis Toolbox, an open source library for efficient and scalable visualization and analysis of deep neural network loss landscapes in Tensorflow and PyTorch. Introducing more efficient mathematical formulations and a novel parallelization scheme, GradVis allows to plot 2d and 3d projections of optimization surfaces and trajectories, as well as high resolution second order gradient information for large networks.