The "default" rank of the monadic verb < (Box) is infinite so it will operate on the whole of its right argument at once. Hence:
< i. 2 2 +---+ |0 1| |2 3| +---+ by adding "1 to the verb we are feeding the argument to the verb a 1-cell at-a-time. As has already been shown, the 1-cells of ( i.2 2 ) are ( 0 1 ) and ( 2 3 ), and applying Box to those cells gives: <"1 i. 2 2 +---+---+ |0 1|2 3| +---+---+ You can find the "default" rank of a verb by looking it up in the Dictionary or by asking the interpreter: < b. 0 _ 0 0 In other words, monadic ( < ) has a rank of ( _ ) and dyadic ( < ) has a left and right ranks of ( 0 0 ) respectively. On Thu, Jun 9, 2011 at 2:56 PM, Randy MacDonald <[email protected]> wrote: > I wonder how the following is explained with rank: > > < i. 2 2 > ┌───┐ > │0 1│ > │2 3│ > └───┘ > <"1 i. 2 2 > ┌───┬───┐ > │0 1│2 3│ > └───┴───┘ > > The posted explanations seem to be missing something... > > > On 6/8/2011 11:21 PM, Ian Clark wrote: >> Thank you, Kent, for posing a newbie question that crystallises the >> essence of Rank ("). And thanks to those who've offered an answer. >> >> I was just about to supply the content for the NuVoc entry on Rank: >> http://www.jsoftware.com/jwiki/Vocabulary/quote >> Your micro-example spotlights exactly what a novice needs to be told >> about it. I shall use it. >> >> >> >> On Wed, Jun 8, 2011 at 10:47 PM, Henry Rich<[email protected]> wrote: >>> You almost had it. I've fixed the error below. >>> >>> Henry Rich >>> >>> On 6/8/2011 5:41 PM, Squint6 wrote: >>>> Hi, >>>> >>>> >>>> I have just started with J and I have a question concerning rank (I think). >>>> >>>> >>>> I don't understand why the following does what it does: >>>> >>>> >>>> a=. 2 2 $ i.4 >>>> >>>> >>>> b=.+/a >>>> >>>> >>>> c=.+/"1 a >>>> >>>> >>>> After executing these lines >>>> a contains >>>> 0 1 >>>> 2 3 >>>> b contains 2 4 and >>>> c contains 1 5 >>>> >>>> >>>> I understand where b is coming from but c's value confuses me. Here's how >>>> my (faulty) reasoning about c=.+/"1 a goes. >>>> The "1 applies to the verb (+/) giving it a rank of 1. Therefore (+/) is >>>> applied to the 1-cells of a, >>>> which I believe are the lists (0 1) and (2 3). >>> ERROR FIXED HERE: >>>> Therefore we have (+/ 0 1) , (+/ 2 3) >>>> >>>> >>>> Thanks. >>>> Kent >>>> >>>> >>>> >>>> ---------------------------------------------------------------------- >>>> 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
