October 20, 2007

I have become fascinated with dendrochronology (dendro). Dendro is the science that analyzes temporal and spatial consistencies of various processes using tree rings. The tree rings are dated to their exact year of formation. This data can be used across several disciplines: anthropology, geology, climatology, and ecology– to just name a few.

Of course, there is a ton of data to analyze. The primary data bank is located at The International Tree-Ring Data Bank and is maintained by the NOAA Paleoclimatology Program and World Data Center for Paleoclimatology. It includes raw ring width or wood density measurements, and growth indices for a site.

I am very excited to combine this mass amount of raw data with the power of lisp! I will document my adventures for those who are interested.



  1. ken Says:

    In a former life, I used to write dendrochronology software. I played around with Lisp some at the time, though I ended up not using it because the GUI situation (among other things) at the time was kind of dire (and perhaps still is).

    I’ll look around to see if I have any of my old Lisp code still. If not, I can at least point you at the algorithms and help you with the (undocumented) file formats.

    There’s lots of good news here:
    – the datasets are generally “big lists of (small positive) integers” (plus a hash of metadata), which Lisp can slice through like a hot knife through butter
    – the state-of-the-art algorithms aren’t that complex (or, alternatively, there’s lots of exploration left to be done!)
    – there’s a ton of free data to play with, as you’ve found
    – there’s even some free software to be found, though sometimes you have to type it in and port it from ALGOL or a very early FORTRAN and then fix the bugs
    – a lot of the algorithms are more or less just “try to do by computer what your eye can do”, so you can make pretty graphics and test your heuristic by just looking at it

    Let me know if you have any questions — I’m kind of busy these days, but this sounds like fun.

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