travelog – monday
Oct 6th 2004WallabyGeneral & nerd alert
I’m a couple days behind already, other days to follow as I catch up… eventually?
Flight to Portland was uneventful, except for Mt. St. Helens erupting a little bit more halfway through. The pilot called our attention to the dramatic view of an irregular cloud of dust hovering on the horizon. So now I’ve seen a volcano… guess that just leaves an earthquake before my natural disaster collection is complete. I can wait.
Two great talks Monday afternoon, on generalized two-dimensional correlation stuff. The usual use of generalized 2D correlation is to correlate a set of data with itself, each set representing a different set of conditions. For instance, the dissociation of a weakly bound complex as the temperature rises. This tells one which peaks change at the same time (synchronous) or before/after (asynchronous) peaks… useful in picturing just what’s going on.
These two talks (Dluhy at UGeorgia, and Blades et al. at British Columbia) extend that. Dluhy correlates the set of perturbed data with a function that (might) model the data, such as a sine function (plotting correlation for different wavelengths at different phase angles, or frequencies) or an exponential (plotting versus rate constants). The Blades group does some funky stuff that picks out correlation of individual wavelengths/peaks with perturbation, by adding a delta function to the end of each spectrum (different position for each, so that each perturbation step is uniquely tagged). The data set, with tags, is then correlated with itself, as usual. The covariance of the tags means nothing, of course, but the covariance of the tags for different perturbation steps and the wavelengths shows how peaks change over time… which is difficult/impossible to extract from the “simple” 2D correlation matrix. (It’s also extra-handy for picking up which perturbation level a change begins at.)
Dinner Monday with the advisor and a couple other folks. Exceptionally tasty. My advisor cheerfully predicted that, once I start writing grants that get rejected and dealing with graduate students, I too will turn to drink.
