Michael Dykman <[email protected]> writes: > If I recall my history correctly, APL was used productively as a > blackboard notation at IBM for a couple of years before the first > interpreter was written. Ken's object was to create a consistent > mathematical notation which academic mathematics had failed to do.
Yes, I've certainly heard that, but my attempts at trying that myself haven't had much success. For example, "*" takes much longer to write than "\cdot", and I have a hard time writing "\times" precisely enough for it not to be confused with "x". (For my own paper-only use, I've settled on using \cdot for multiplication most of the time, but then *: when squaring, etc. Similarly, I might as well use \uparrow and \downarrow for take/drop and \div for division.) I'm still working on a good notation for expectation over a distribution and conditional probability. E[x], p(x|y), etc. For example, Bayes's Rule looks ok as P(A|B) = P(B|A)P(A) / P(B), but if I want "J-like" notation, I end up taking back [] and writing P[A|B]=P[B|A]*P[A]%P[B], but then I have to remember that those "|"'s are special. Maybe: (B P. A)=(A P. B)*(P. A)%P. B In any case, it's fun to experiment with. Thanks, Johann > > - michael dykman > > > On Fri, Jul 15, 2011 at 11:19 AM, Raul Miller <[email protected]> wrote: >> On Fri, Jul 15, 2011 at 11:02 AM, Johann Hibschman >> <[email protected]> wrote: >>> I've experimented a bit with using J- or APL-like notation for pencil >>> and paper math, with some mixed success. Has anyone else tried this >>> much? >> >> I have, but I almost always use j's ide (with test data) rather than >> paper and pencil. >> >> I might occasionally resort to paper for a diagram or to use an >> alternate notation or whatever, but I really like having test data to >> help me see when I have gone off track. >> >> FYI, >> >> -- >> Raul >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm >> ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
