Roger Hui <[EMAIL PROTECTED]> wrote: > f d. 1 is a symbolic differentiator and is table driven plus a few rules. > In this case I believe it tried to use the product rule and then > foundered on the monad * which is not differentiable. In contrast: > > (1&o. * 2&o.) d. 1 > (2&o. * 2&o.) + 1&o. * -@(1&o.) > > For * * *: to be differentiable the function itself would have to > be in the table.
Since there appears to be a substantial behavioral difference between f d.1 and f D. 1, perhaps the dictionary should reflect this? I once stumbled across the same thing, and was baffled by it, since there was no documentation about the different semantics. Also, it might be a good idea to have f d.1 to degenerate gracefully to f D.1"0 rather than a domain error in cases where it can't use the tables. -- Mark D. Niemiec <[EMAIL PROTECTED]> ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
