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Fast Gaussian process regression for high dimensional functions with derivative information
Proceedings of the First International Conference on Probabilistic Numerics, PMLR 271:35-49, 2025.
Abstract
Gaussian process regression (GPR) is the backbone of many methods in probabilistic numerics. Exact GPR on $n$ sampling locations in $d$ dimensions generally requires $\mathcal{O}(n^2)$ storage and costs $\mathcal{O}(n^3+dn^2)$ to fit assuming kernel evaluation costs $\mathcal{O}(d)$. Using certain pairings of sampling locations and kernels induces nice structure into the Gram matrix and enables accelerated exact GPR. One popular pairing uses Cartesian grids with product kernels to induce Kronecker structure in the Gram matrix. This reduces exact GP fitting costs to $\mathcal{O}(d n^{3/d})$ and storage requirements to $\mathcal{O}(d n^{2/d})$, but quickly becomes intractable when the dimension exceeds a few dozen. Recent work has shown that pairings certain low discrepancy sequences with special kernels enables GPR to scale like $\mathcal{O}(n \log n + nd)$ for fitting costs and $\mathcal{O}(n)$ for storage requirements. We describe an extension of these methods to problems which observe $m$ derivative multi-indices at each of the $n$ low discrepancy sampling locations. By exploiting similar structure across blocks of the Gram matrix, we are able to reduce the GP fitting cost from $\mathcal{O}(n^3 m^3 + n^2m^2d)$ to $\mathcal{O}(m^2 n \log n+m^3n + n m^2 d)$ and reduce the storage requirements from $\mathcal{O}(n^2 m^2)$ to $\mathcal{O}(nm^2)$. We explore a number of synthetic benchmarks to illustrate the potential of the proposed approach.