Bill Harris <[email protected]> writes: > Does anyone do that with J? I do take notes that way sometimes but not > as often as I did with APL. Perhaps that's partially due to my changing > professional roles, but I still do analysis. Perhaps that's partially > due to much of my current analysis being done in R (*). Perhaps that's > because J gave us the ability to craft really powerful and really > compact one-line programs that are hard to get right and expressive > without a computer to test them.
[...] > How do others react to this notion? Do you regularly take notes in J? > In what domains? In tacit / explicit notation? I find that J's dot- and colon-inflected symbols work well when typing into a computer, but poorly when handwriting. When working things out on paper, I mostly use "traditional notation," with a melange of J and APL symbols thrown in when they make sense. However, speaking for myself, any notes that I want to be able to find in a year have to be electronic. I find J works very well for that, at least for "computation-oriented" notes. It works less well for more symbolic things like stochastic calculus or Bayesian inference. As an example, I just read a paper on methods of combining multiple econometric forecasts into a smart consensus and used J to write down the different "win" metrics discussed in the paper. It was handy and concise, with one big caveat: I completely ignored any issues with missing data, assuming that all the arrays were dense. That was fine for note-taking, but if I wanted to implement it "for real", I would have to carry around a mask array and update it on each step, which would make the notation much less appealing. Right now, I'm implementing the "for real" version in R and appreciating the built-in missing-value support. Johann ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
