iota =: i. : (+ i.)
1 iota 51 2 3 4 5 iota is 0 based if monadic, right argument based if dyadic. if there were more "ascii op codes" an ideal design for every verb would have the monadic version be a "default argument" version of a dyadic form. ________________________________ From: 'Skip Cave' via Programming <[email protected]> To: [email protected] Sent: Monday, December 31, 2018 11:42 AM Subject: Re: [Jprogramming] One-based indices To replace my proposed i; i1=: >:@i. On Mon, Dec 31, 2018, 10:38 AM Skip Cave <[email protected] wrote: > Or >:i. > > On Dec 31, 2018 10:34 AM, "Raul Miller" <[email protected]> wrote: > > In every culture, some traditions are worth keeping, while some are > worth abandoning (and some are so entrenched that they're best > encapsulated and tolerated). > > Details of our calendar (which date back to the Roman Empire) are > probably best treated in much the same way we treat details of roman > numerals. Or, my take: surviving roman traditions tend to work well > enough for their purpose, but do not work well enough for all similar > purposes... (there's a reason, for example, why people in astronomical > communities deal with leap seconds, and why they mostly ignore months > in their time keeping efforts...) > > Also, I've used quadIO. For people who don't know: that was APL's > tactic for dealing with different concepts of the numerical value of > the first element of an array. But quadIO was a complete pain that > hit me every time I needed to use numeric indices. > > On the other hand, the problems surrounding APL's quadIO did have the > benefit of discouraging me from using indices wherever possible. But > this had a significant disadvantage also: sometimes the resulting code > was way more elaborate than I anticipated when I started writing it. > (Which, in turn, is a big deal when you're phasing things into > production over time, based on an agreed-on end goal.) > > That said, this works just fine: > > 1+i.2 4 > > 1 2 3 4 > 5 6 7 8 > > (And, for anyone keeping track, *this* time I used copy and paste, > rather than hand typing onto my phone from an untrusted computer.) > > Thanks, > > > -- > Raul > > > > > > > On Sun, Dec 30, 2018 at 6:13 PM 'Bo Jacoby' via Programming > <[email protected]> wrote: > > > > New year's day is January the first, not January the zeroth. > > 'The first' is an ordinal number - not a cardinal number. > > A zero-origin index counts how many elements to skip before reaching a > certain element. It is a cardinal number - not an ordinal number. Zero is a > cardinal number - 'zeroth' is not an ordinal number. > > Not distinguishing cardinal numbers from ordinal numbers creates > confusion. > > Thanks. Bo. > > Den søndag den 30. december 2018 18.54.48 CET skrev Henry Rich < > [email protected]>: > > > > That's the correct result. #\ operates on prefixes of y, which are > tables. > > > > Henry Rich > > > > > > On 12/30/2018 12:28 PM, Linda Alvord wrote: > > > #\i.8 3 > > > 1 2 3 4 5 6 7 8 > > > > > > Sorry, Linda > > > > > > > > > > > > Sent from my Verizon, Samsung Galaxy smartphone > > > > > > > > > -------- Original message -------- > > > From: Linda Alvord <[email protected]> > > > Date: 12/30/18 12:24 PM (GMT-05:00) > > > To: [email protected] > > > Subject: Re: [Jprogramming] One-based indices > > > > > > This doesn't work. > > > > > > #i.8 3 > > > 1 2 3 4 5 6 7 8 > > > > > > > > > Linda > > > > > > Sent from my Verizon, Samsung Galaxy smartphone > > > > > > > > > -------- Original message -------- > > > From: Henry Rich <[email protected]> > > > Date: 12/30/18 12:08 AM (GMT-05:00) > > > To: [email protected] > > > Subject: Re: [Jprogramming] One-based indices > > > > > > Seconded. If you must create lists starting at 1, keep in mind > > > > > > #\ 'abcdefgh' > > > > > > 1 2 3 4 5 6 7 8 > > > > > > > > > which Roger even supported with special code. > > > > > > > > > Henry Rich > > > > > > > > > > > > > > > On 12/29/2018 11:49 PM, Roger Hui wrote: > > >> Why not use >:@i. ? > > >> > > >> WRT a 1-origin primitive, don't do it! Even non-APL people know this. > > >> See *Why > > >> numbering should start at zero > > >> < > https://nam02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.cs.utexas.edu%2Fusers%2FEWD%2Fewd08xx%2FEWD831.PDF&data=02%7C01%7C%7C9e44f8b9de4d49a54aac08d66e7b98c7%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636817874454098584&sdata=SwB6%2FtOljN%2BEhNXUoESr4X4bSNi4a3lOTXbbTiw97C0%3D&reserved=0 > >.* > > >> > > >> 1-origin *delenda est*. > > >> > > >> > > >> > > >> On Sat, Dec 29, 2018 at 8:22 PM 'Skip Cave' via Programming < > > >> [email protected]> wrote: > > >> > > >>> I find that I need to use the expression 1+i.x much more often than > I use > > >>> i.x. > > >>> Would it make sense to define the primitive i; as the one-origin > version of > > >>> i.? > > >>> > > >>> i. 5 > > >>> > > >>> 0 1 2 3 4 > > >>> > > >>> i; 5 > > >>> > > >>> 1 2 3 4 5 > > >>> > > >>> i. 2 3 > > >>> > > >>> 0 1 2 > > >>> > > >>> 3 4 5 > > >>> > > >>> i; 2 3 > > >>> > > >>> 1 2 3 > > >>> > > >>> 4 5 6 > > >>> > > >>> > > >>> This avoids all the side effects of quad IO in APL but provides a > handy way > > >>> to generate one-based indices. > > >>> > > >>> > > >>> Skip > > >>> > ---------------------------------------------------------------------- > > >>> For information about J forums see > https://nam02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.jsoftware.com%2Fforums.htm&data=02%7C01%7C%7C9e44f8b9de4d49a54aac08d66e7b98c7%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636817874454098584&sdata=rEAdhjw7xl8avJsOiugshj1EZffAbHvUKhhjF2hbEQg%3D&reserved=0 > > >> ---------------------------------------------------------------------- > > >> For information about J forums see > https://nam02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.jsoftware.com%2Fforums.htm&data=02%7C01%7C%7C9e44f8b9de4d49a54aac08d66e7b98c7%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636817874454098584&sdata=rEAdhjw7xl8avJsOiugshj1EZffAbHvUKhhjF2hbEQg%3D&reserved=0 > > > > > > > > > --- > > > This email has been checked for viruses by AVG. > > > > https://nam02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.avg.com&data=02%7C01%7C%7C9e44f8b9de4d49a54aac08d66e7b98c7%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636817874454098584&sdata=p0QxrFpfFhA9pyQ%2FZRa6Ekin4BNKn3BLvWGk%2Fqe3W3A%3D&reserved=0 > > > ---------------------------------------------------------------------- > > > For information about J forums see > https://nam02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.jsoftware.com%2Fforums.htm&data=02%7C01%7C%7C9e44f8b9de4d49a54aac08d66e7b98c7%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636817874454098584&sdata=rEAdhjw7xl8avJsOiugshj1EZffAbHvUKhhjF2hbEQg%3D&reserved=0 > > > ---------------------------------------------------------------------- > > > For information about J forums see > https://nam02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.jsoftware.com%2Fforums.htm&data=02%7C01%7C%7C9e44f8b9de4d49a54aac08d66e7b98c7%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636817874454254828&sdata=MLxReCknfAxge%2BDeH0pIQHKY6WA7hSRd5998SEb3kJw%3D&reserved=0 > > > ---------------------------------------------------------------------- > > > For information about J forums see http://www.jsoftware.com/forums.htm > > > > > > --- > > This email has been checked for viruses by AVG. > > https://www.avg.com > > > > ---------------------------------------------------------------------- > > 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 ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
