Hi Dan sincos=.1&o.&.+: NB. is cuter. --- Den lør 20/11/10 skrev Dan Bron <[email protected]>:
> Fra: Dan Bron <[email protected]> > Emne: Re: [Jprogramming] Accessing a verb as the composition ofits"primitives" > Til: "J Programming" <[email protected]> > Dato: lørdag 20. november 2010 00.26 > Bingo. > > Or, to put it another way, > > (1&o. * 2&o.) d. 1 > and > sincos d. 1 > > mean the same thing, because > (1&o. * 2&o.) > and > sincos > mean the same thing. As proof, try sincos d.1 > f. instead of sincos f. d. 1 . > > -Dan > > > PS: of course if you're treating sincos vs (1&o. * > 2.&o.) textually or grammatically, they look different; > I'm just talking about syntactic equivalence here. > > > BTW, 1 2 */ .(o./) ] is a fun semantic equivalent to > sincos (which is different from syntactic equivalence! > eg d. won't work). Can anyone make that cuter? > > > > Please excuse typos; composed on a handheld device. > > -----Original Message----- > From: "Sherlock, Ric" <[email protected]> > Sender: [email protected] > Date: Sat, 20 Nov 2010 11:56:26 > To: Programming forum<[email protected]> > Reply-To: Programming forum <[email protected]> > Subject: Re: [Jprogramming] Accessing a verb as the > composition of > its"primitives" > > There may be there is some confusion here. > > What Dan is saying is that the following two lines give the > same result (which they do for me): > (1&o. * 2&o.) d. 1 ] 0.4 > 0.69670671 > sincos d. 1 ] 0.4 > 0.69670671 > > In other words the derivative of sincos is correctly taken > when sincos d. 1 is applied to arguments, it just doesn't > "show" the algebraic solution when entered without > arguments. If you want that then use f. as Raul suggests. > > > > From: Alex Gian > > Sent: Saturday, 20 November 2010 11:33 > > > > Not on any of the J systems I've tried! > (Including Linux, Win32(Wine), > > or Windows Mobile / PPC) > > > > I thought it was just a weird peculiarity of J, > obviously d. "should" > > work on a user defined verb if it can. > > > > I tried with other verbs, like p. too, just in case o. > was causing the > > problem. Nope, once you define a verb in terms > of its primitives d. > > don't work no more. Just FYI > > > > On Fri, 2010-11-19 at 21:58 +0000, Dan Bron wrote: > > > Raul is right, but just to be clear, when applied > to arguments, sincos d. 1 > > and sincos f. d. 1 will have identical > results*. Just type into the IJX > > without arguments, the latter looks different from the > former for exactly the > > same reason sincos f. looks different from > sincos . > > > > > > That is, f. explicitly requests its argument be > exploded into its components > > (but again, the argument to f. applied to its own > arguments will havbe the > > same results, exploded or not - that's the point of > naming stuff - > > subordinating detail / hiding complexity). > > > > > > -Dan > > > > > > * I haven't tested this, but if it isn't true, > that's an interpreter bug. > > > > > > > > > > > > > > > Please excuse typos; composed on a handheld > device. > > > > > > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
