Thank you so much for the details in #43 and #44! I'm going to see if I can adapt the PODES work, per [Bayesian uncertainty quantification for differential equations](http://andrewgelman.com/2014/04/29/bayesian-uncertainty-quantification-differential-equations/) and [Bayesian Analysis of ODE's: solver optimal accuracy and Bayes factors](http://arxiv.org/abs/1311.2281), and perhaps [methods by Soetaert and Herman](https://cran.r-project.org/web/packages/ecolMod/index.html) and [from their book](http://www.springer.com/us/book/9781402086236).