I’m using UQLab with PCE surrogate models to speed up Bayesian inference. I looked at the beam calibration case (https://www.uqlab.com/copy-of-inversion-map-estimation), and got some idea about how this works. However, in the documentation on Bayesian inference (https://uqftp.ethz.ch/uqlab_doc_pdf/1.3.0/UserManual_Bayesian.pdf) I cannot find more detailed information related to this option. One concrete question is: is the sampling for the surrogate model based on the prior? If yes, how does the surrogate model know about this? Can this be changed? How to specify sampling schemes?