About a dozen people suffered through my hour-and-a-half talk on J. There were about 35 people registered but this turn-out was pretty good for blizzard conditions. You can see some of the responses here: http://www.meetup.com/7-Languages-in-7-Months-NYC/events/158287762/ .
I've posted my slides on the J wiki - http://www.jsoftware.com/jwiki/DevonMcCormick/JTalk20140121 . I've started to annotate them but have only done the first few. On Tue, Jan 21, 2014 at 9:56 PM, Pascal Jasmin <godspiral2...@yahoo.ca>wrote: > most useful fork I know personally: > > inl =: (cocurrent@] ".@] [)"1 0 > > 'code to run in locales' inl loc1;loc2;loc3 > > the neat parts about it: > > the left verb is sideeffects only. > the pivot verb is monadically applied to right verb result > the locale list is usually a list of numeric object instances. > > ________________________________ > From: Devon McCormick <devon...@gmail.com> > To: J-programming forum <programm...@jsoftware.com> > Sent: Monday, January 20, 2014 12:48:59 PM > Subject: Re: [Jprogramming] more fork examples > > > I won't use this as an example for this talk. If I do elaborate on matrix > multiplication, I usually like to emphasize how this is a specific instance > of a more general concept. > > The problem I'm having now is that I'd like to use the power conjunction as > my example but I'm placing it in a hierarchy like this: > > J Parts of Speech: a Functional Hierarchy > Name Argument Type Example? > Conjunction Verbs > Adverb Verbs and nouns > Verb Nouns > Noun - > > but I have not been able to come up with a good, simple example of the > power conjunction using a couple of verbs. The best I have so far is from > Roger's essay: "Do While" using power conjunction: > http://www.jsoftware.com/jwiki/Essays/Do%20While . He uses this example - > which is pretty good for my purposes: > > (1+3*])^:(1e5&>)^:_]3 > > but does not resonate as some kind of well-known problem. I wanted to do > something like this (to find the first Fibonacci number greater than 4e6): > > fib^:(4e6&>)^:_]1 > > but I end up writing it like this: > > (([: >: {.) , [: (fib) {.)^:(4000000 > {:)^:_]1 > 35 5702887 > > (so the 34th term is the one I'm looking for) but this involves too many > symbols I have not yet introduced or are otherwise unfamiliar. > > Anyway, I have to finish this up in the next few hours so I can start > practicing it. > > > > On Mon, Jan 20, 2014 at 12:51 AM, Henry Rich <henryhr...@nc.rr.com> wrote: > > > If you use this as an example, be sure you can explain how +/ . *, which > > is usually matrix multiplication, applies to these operands which are not > > matrices. Mathematically it would be an error to matrix-multiply two > > vectors of the same shape. > > > > Henry Rich > > > > > > On 1/20/2014 12:14 AM, Devon McCormick wrote: > > > >> NB. Weighted mean: > >> > >> 1 10 1 ((+/ . *) % ([:+/[)) 10 2 30 > >> > >> 5 > >> > >> > >> On Thu, Jan 16, 2014 at 8:09 PM, Roger Hui <rogerhui.can...@gmail.com> > >> wrote: > >> > >> The put down was for not so much that our system was not capable of > >>> sensitivity analysis, or perhaps that we did not even know what > >>> sensitivity > >>> analysis was, but that we were unwilling to admit it. > >>> > >>> ----------- > >>> > >>> The braggart claims to have Superman's powers. > >>> > >>> "Can you crush things like Superman?" > >>> > >>> The braggart took a walnut in each hand, absolutely crushed them to a > >>> pulp, > >>> and said, "Yes, I can." > >>> > >>> "Can you see far away like Superman?" > >>> > >>> The braggart flipped down a pair of binocular glasses he was wearing > and > >>> read out the words on the sign at the end of the block, and said, "Yes > I > >>> can." > >>> > >>> "Can you fly like Superman?" > >>> > >>> The braggart walked up to the roof of a 3-floor building, and jumped > off > >>> with a flying leap! Splat! With great struggle and lots of moaning, > he > >>> raised himself up on his elbows, and said, "Yessssh, yesh, ... yesh I > >>> can." > >>> > >>> > >>> > >>> > >>> On Thu, Jan 16, 2014 at 2:16 PM, Dan Bron <j...@bron.us> wrote: > >>> > >>> I don't get the put-down (or joke). Can you explain it to me? > >>>> > >>>> -Dan > >>>> > >>>> > >>>> ----- Original Message --------------- > >>>> > >>>> Subject: Re: [Jprogramming] more fork examples > >>>> From: Roger Hui <rogerhui.can...@gmail.com> > >>>> Date: Thu, 16 Jan 2014 13:14:12 -0800 > >>>> To: Programming forum <programm...@jsoftware.com> > >>>> > >>>> Thanks for the compliment but what I really need are for y'all to send > >>>> me > >>>> quotes/anecdotes not yet in the list. For example: > >>>> > >>>> Once, in the early 1980s, Ken Iverson visited us in Calgary. Fred > >>>> Appleyard and I proudly showed off our system implemented in direct > >>>> definition. Ken asked a question which is essentially, "Can you do > >>>> sensitivity analysis?" We start mumbling something. Ken says, "Can > you > >>>> touch your shoulder?", and proceeded to reach behind his neck to touch > >>>> > >>> the > >>> > >>>> opposite shoulder. I have yet to recover from this put-down :-). > >>>> > >>>> BTW, among the APL crowd, accusing somebody of "mumbling something" is > >>>> > >>> done > >>> > >>>> by putting your hand in front of your mouth and muttering, "but ah eh > >>>> > >>> blah > >>> > >>>> blah ...". > >>>> > >>>> > ---------------------------------------------------------------------- > >>> For information about J forums see http://www.jsoftware.com/forums.htm > >>> > >>> > >> > >> > >> ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > > > > > > -- > Devon McCormick, CFA > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > -- Devon McCormick, CFA ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
