[edit]
Variational zero-inflated Gaussian processes with sparse kernels
Proceedings of the 34th Conference on Uncertainty in Artificial Intelligence, PMLR R16:360-370, 2018.
Abstract
Zero-inflated datasets, which have an ex- cess of zero outputs, are commonly en- countered in problems such as climate or rare event modelling. Conventional ma- chine learning approaches tend to overesti- mate the non-zeros leading to poor perfor- mance. We propose a novel model family of zero-inflated Gaussian processes (ZiGP) for such zero-inflated datasets, produced by sparse kernels through learning a la- tent probit Gaussian process that can zero out kernel rows and columns whenever the signal is absent. The ZiGPs are particu- larly useful for making the powerful Gaus- sian process networks more interpretable. We introduce sparse GP networks where variable-order latent modelling is achieved through sparse mixing signals. We derive the non-trivial stochastic variational infer- ence tractably for scalable learning of the sparse kernels in both models. The novel output-sparse approach improves both pre- diction of zero-inflated data and inter- pretability of latent mixing models.