exoplanetary transit and secondary-eclipse light curves ([@gibson_gaussian_2012] and [@evans_uniform_2015]), to map interstellar extinction within the Milky Way [@sale_three-dimensional_2014], and to fit semi-analytic models of galaxy formation [@bower_parameter_2010], while in the cosmological literature it has has been used to predict the nonlinear matter power spectrum in the Coyote Universe simulation [@heitmann_coyote_2009], and to fit Gravitational-wave models [@moore_improving_2016]. In the dynamical modelling of stellar systems, GPE may allow us the use of more-expensive static models or even full $N$-body models. In this paper we take a step towards this goal by introducing the method and demonstrating its use with a toy model, namely a single-component anisotropic Plummer sphere, which we fit to synthetic data drawn from the same model. We focus on distribution function-based models of the internal dynamics of a galaxy in order to illustrate the value of the GPE approach. However, we note that in principle the GPE approach is applicable to any dynamical modelling scheme.

To avoid confusion, a word of clarification is in order with respect to terminology. The term ‘Gaussian’ in ‘Gaussian-process emulation’ refers only to assumptions within the emulation scheme. It does not imply any assumptions regards the Gaussianity, or otherwise, of any properties of the 