no code implementations • 6 Dec 2024 • Narayan Srinivasan, Matthew Sutton, Christopher Drovandi, Leah F South
We propose a novel method for measuring the discrepancy between a set of samples and a desired posterior distribution for Bayesian inference.
1 code implementation • 18 Nov 2024 • David T. Frazier, Ryan Kelly, Christopher Drovandi, David J. Warne
Neural posterior estimation (NPE) and neural likelihood estimation (NLE) are machine learning approaches that provide accurate posterior, and likelihood, approximations in complex modeling scenarios, and in situations where conducting amortized inference is a necessity.
no code implementations • 29 Sep 2024 • Xiaoyu Wang, Ryan P. Kelly, Adrianne L. Jenner, David J. Warne, Christopher Drovandi
In this paper, we provide comprehensive guidelines for deciding between SBI approaches for complex biological models.
no code implementations • 1 May 2024 • Sarah A. Vollert, Christopher Drovandi, Matthew P. Adams
Ecosystem models are often constructed by assuming stability and coexistence in ecological communities as a proxy for abundance data when monitoring programs are not available.
no code implementations • 21 Apr 2024 • Xiaoyu Wang, Ryan P. Kelly, David J. Warne, Christopher Drovandi
To overcome this, we propose preconditioned NPE (PNPE) and its sequential version (PSNPE), which uses a short run of ABC to effectively eliminate regions of parameter space that produce large discrepancy between simulations and data and allow the posterior emulator to be more accurately trained.
no code implementations • 21 Jul 2023 • Sarah A. Vollert, Christopher Drovandi, Matthew P. Adams
Additionally, we demonstrate how to identify the parameter combinations that strongly drive feasibility and stability, drawing ecological insight from the ensembles.
1 code implementation • 24 May 2023 • Nhat-Minh Nguyen, Minh-Ngoc Tran, Christopher Drovandi, David Nott
We combine the Wasserstein Gaussianization transformation with robust BSL, and an efficient Variational Bayes procedure for posterior approximation, to develop a highly efficient and reliable approximate Bayesian inference method for likelihood-free problems.
1 code implementation • 10 Nov 2022 • Joshua J Bon, David J Warne, David J Nott, Christopher Drovandi
In this paper we propose a new method for adjusting approximate posterior samples to reduce bias and produce more accurate uncertainty quantification.
1 code implementation • 22 Oct 2022 • Laurence Davies, Robert Salomone, Matthew Sutton, Christopher Drovandi
Reversible jump Markov chain Monte Carlo (RJMCMC) proposals that achieve reasonable acceptance rates and mixing are notoriously difficult to design in most applications.
no code implementations • 14 Jul 2022 • Christopher Drovandi, David J Nott, David T Frazier
We describe an idealized low-dimensional summary statistic that is, in principle, suitable for marginal estimation.
no code implementations • 28 Oct 2020 • Julia Camps, Brodie Lawson, Christopher Drovandi, Ana Minchole, Zhinuo Jenny Wang, Vicente Grau, Kevin Burrage, Blanca Rodriguez
We demonstrate results from our inference method on a cohort of twenty virtual subjects with cardiac volumes ranging from 74 cm3 to 171 cm3 and considering low versus high resolution for the endocardial discretisation (which determines possible locations of the earliest activation sites).
1 code implementation • 8 Sep 2020 • Joshua J Bon, Anthony Lee, Christopher Drovandi
Delayed-acceptance is a technique for reducing computational effort for Bayesian models with expensive likelihoods.
Computation Methodology
1 code implementation • 20 Mar 2020 • Steven Kleinegesse, Christopher Drovandi, Michael U. Gutmann
We address this gap in the literature by devising a novel sequential design framework for parameter estimation that uses the Mutual Information (MI) between model parameters and simulated data as a utility function to find optimal experimental designs, which has not been done before for implicit models.
no code implementations • 11 Sep 2019 • Jacob W. Priddle, Scott A. Sisson, David T. Frazier, Christopher Drovandi
Bayesian synthetic likelihood (BSL) is a popular such method that approximates the likelihood function of the summary statistic with a known, tractable distribution -- typically Gaussian -- and then performs statistical inference using standard likelihood-based techniques.
no code implementations • 25 Jul 2019 • Ziwen An, Leah F. South, Christopher Drovandi
Instead of evaluating the likelihood, BSL approximates the likelihood of a judiciously chosen summary statistic of the data via model simulation and density estimation.
1 code implementation • 5 Jun 2019 • Christopher Drovandi, Richard G. Everitt, Andrew Golightly, Dennis Prangle
Particle Markov chain Monte Carlo (pMCMC) is now a popular method for performing Bayesian statistical inference on challenging state space models (SSMs) with unknown static parameters.
Computation Methodology
1 code implementation • 9 Apr 2019 • David T. Frazier, Christopher Drovandi
Similar to other approximate Bayesian methods, such as the method of approximate Bayesian computation, implicit in the application of BSL is the maintained assumption that the data generating process (DGP) can generate simulated summary statistics that capture the behaviour of the observed summary statistics.
Methodology Applications Computation
1 code implementation • 25 Feb 2019 • David J. Warne, Scott A. Sisson, Christopher Drovandi
We illustrate the potential of SIMD for accelerating Bayesian computations and provide the reader with techniques for exploiting modern massively parallel processing environments using standard tools.
1 code implementation • 13 Nov 2018 • Leah F. South, Antonietta Mira, Christopher Drovandi
Zero-variance control variates (ZV-CV) are a post-processing method to reduce the variance of Monte Carlo estimators of expectations using the derivatives of the log target.
Computation Methodology