Distributional Computational Graphs: Error Bounds
Olof Hallqvist Elias, Michael Selby, Phillip Stanley-Marbell
TL;DR
Distributional computational graphs (DCGs) propagate known input distributions through deterministic operations and study how finite input representations affect the output distribution. The authors derive non-asymptotic Wasserstein-1 bounds that quantify error propagation along all source-to-output paths, with the amplification determined by path Lipschitz constants and the graph structure. They provide a general bound for arbitrary DCGs and a specialized bound for the Euler–Maruyama scheme, including a sharp Gaussian quantization rate $W_1(\mu,\mu^{(n)})=O(2^{-n})$ and an EM error bound of the form $W_1(\mu_k,\mu_k^{(n),c})\le c e^{c' k\sqrt{n\Delta t}}/2^{n}$. This work offers a deterministic alternative to Monte Carlo with explicit error control for propagating distributions in numerical schemes and probabilistic reasoning, highlighting trade-offs between graph complexity, approximation level, and accuracy.
Abstract
We study a general framework of distributional computational graphs: computational graphs whose inputs are probability distributions rather than point values. We analyze the discretization error that arises when these graphs are evaluated using finite approximations of continuous probability distributions. Such an approximation might be the result of representing a continuous real-valued distribution using a discrete representation or from constructing an empirical distribution from samples (or might be the output of another distributional computational graph). We establish non-asymptotic error bounds in terms of the Wasserstein-1 distance, without imposing structural assumptions on the computational graph.
