Hi All,

I am comparing the posterior predictions for a simple non-linear regression problem $k= \exp(a+b/T) $, between stan and rstanarm/glm.

The prediction with rstanarm/glm is surprisingly noisy in lower part of the control variable range (see image below).

This looks like a numerical problem, but I do not know how to investigate…

Red dots are the calibration data; orange bars depict prediction 95% CI by combination of variances from the posterior.

The source code:

testArrhenius.R (2.5 KB)

Operating System: debian 9.3

Interface Version: 2.17.2

Compiler/Toolkit: