The day started with Huppenkothen (Amsterdam) and I meeting at a café to discuss what we were going to talk about in the tutorial part of the day. We quickly got derailed to talking about replacing periodograms and auto-correlation functions with Gaussian Processes for finding and measuring quasi-periodic signals in stars and x-ray binaries. We described the simplest possible project and vowed to give it a shot when she arrives at NYU in two months. Immediately following this conversation, we each talked for more than an hour about classical statistics. I focused on the value of standard, frequentist methods for getting fast answers that are reliable, easy to interpret, and well understood. I emphasized the value of having a likelihood function!
In the hack session, I spoke with Eilers (MPIA) and Hennawi (MPIA) about measuring absorption by the intergalactic medium in quasars subject to noisy (and correlated) continuum estimation. Foreman-Mackey explained to me that our failures on K2 the previous night were caused by the inflexibility of the (dumb) PSF model hitting the flexibility of the (totally unconstrained) flat-field. I discussed Gibbs sampling for a simple hierarchical inference with Sick (Queens). And I went through agonizing rounds of good-ideas-turned-bad on classifying pixels in Earth imaging data with Kapadia (Mapbox). On the latter, what is the simplest way to do clustering in the space of pixel histograms?
The research day ended with a discussion of Spectro-Perfectionism (Bolton and Schlegel) with Byler (UW). I told her about the long conversations among Roweis, Bolton, and me many years ago (late 2009) about this. We decided to do a close reading of it (the paper) tomorrow.