The second day of #AstroHackWeek started with Juliana Freire (NYU) talking to us about databases and data management. She also talked about map-reduce and its various cousins. Freire is the Executive Director of the Moore-Sloan Data Science Environment at NYU, and so also our boss in this endeavor (AstroHackWeek is supported by the M-S DSE, and also Github and the LSST project). Many good questions came up in Freire's discussion about the special needs of astronomers when it comes to database choice and customization. Freire opined that one of the reasons that the SDSS databases were so successful is that we had Jim Gray (Microsoft; deceased) and a team working full time on making them awesome. I agree!
In the afternoon, Dalya Baron (TAU) and I made fake data for our galaxy-deprojection project. These data were images with finite point-spread function and Gaussian noise. We then showed that by likelihood optimization we can (very easily, I am surprised to say) infer the Euler angles of the projection (and other nuisance parameters, like shifts, re-scalings, and background level). We also showed that if we have two kinds of three-dimensional galaxies making the two-dimensional images, we can fairly confidently decide which three-d galaxy made which two-d image. This is important for deprojecting heterogeneous collections. I ended the day very stoked about all this!