Progressive gradient walk for neural network fitness landscape analysis

Abstract

Understanding the properties of neural network error landscapes is an important problem faced by the neural network research community. A few attempts have been made in the past to gather insight about neural network error landscapes using fitness landscape analysis techniques. However, most fitness landscape metrics rely on the analysis of random samples, which may not represent the high-dimensional neural network search spaces well. If the random samples do not include areas of good fitness, then the presence of local optima and/or saddle points cannot be quantified. This paper proposes a progressive gradient walk as an alternative sampling algorithm for neural network error landscape analysis. Experiments show that the proposed walk captures areas of good fitness significantly better than the random walks.