To show you that during the operation the item is out of the box and open you can create a verb and have a look.
f=. 3 : 0 smoutput y ) f each a 1 2 3 4 5 7 8 9 11 ++++ ++++ 2010/2/25 Björn Helgason <[email protected]>: > It may be interesting to note that each delivers its results boxed > even if the input is not boxed. > > 3 + &.> i.11 > +-+-+-+-+-+-+-+--+--+--+--+ > |3|4|5|6|7|8|9|10|11|12|13| > +-+-+-+-+-+-+-+--+--+--+--+ > > 2010/2/25 Björn Helgason <[email protected]>: >> each is a very important operation in J >> You can of course use its contants >> >> 3 + &.> a >> +---+-----+-----------+ >> |4 5|6 7 8|10 11 12 14| >> +---+-----+-----------+ >> >> It is a matter of taste which is better to use the primitives directly >> or in a name like each. >> >> 2010/2/25 Björn Helgason <[email protected]>: >>> a=.1 2;3 4 5;7 8 9 11 >>> 3 + each a >>> +---+-----+-----------+ >>> |4 5|6 7 8|10 11 12 14| >>> +---+-----+-----------+ >>> >>> >>> 2010/2/25 Björn Helgason <[email protected]>: >>>> each is an operation that unboxes then operates on the contents and boxes >>>> again >>>> >>>> each >>>> &.> >>>> a=.12;345;789 11 >>>> 3 + a >>>> |domain error >>>> | 3 +a >>>> 3 + each a >>>> +--+---+------+ >>>> |15|348|792 14| >>>> +--+---+------+ >>>> >>>> >>>> 2010/2/25 Alexander Mikhailov <[email protected]>: >>>>> >>>>> I'm a novice in J, and when trying to write programs, I'm very often use >>>>> boxes to store arrays of different length together, like this - >>>>> >>>>> +---+-------+-----+ >>>>> |1 2|3 4 5 6|7 8 9| >>>>> +---+-------+-----+ >>>>> >>>>> Those arrays are usually results of previous steps of computations, and >>>>> semantically the rows are similar, but I can't store them in a table, >>>>> like this - >>>>> >>>>> 1 2 >>>>> 3 4 5 6 >>>>> 7 8 9 >>>>> >>>>> because J requires all items to have the same shape. So, I end up doing >>>>> boxing and unboxing. >>>>> >>>>> As far as I know, the reason to have boxes in J was to allow to have >>>>> elements of different "kinds" - like ranks, or lengths, or types - in the >>>>> same array. Is it reasonable to have boxing/unboxing operations to be >>>>> done implicitly in the case like above - or am I missing other important >>>>> uses of boxes? >>>>> >>>>> Alexander >>>>> >>>>> >>>>> >>>>> >>>>> ---------------------------------------------------------------------- >>>>> For information about J forums see http://www.jsoftware.com/forums.htm >>>>> >>>> >>>> >>>> >>>> -- >>>> Björn Helgason, Verkfræðingur >>>> Fornustekkum II >>>> 781 Hornafirði >>>> Po Box 127,801 Selfoss , >>>> t-póst: [email protected] >>>> gsm: +3546985532 >>>> sími: +3544781286 >>>> http://groups.google.com/group/J-Programming >>>> >>>> >>>> Tæknikunnátta höndlar hið flókna, sköpunargáfa er meistari einfaldleikans >>>> >>>> góður kennari getur stigið á tær án þess að glansinn fari af skónum >>>> /|_ .-----------------------------------. >>>> ,' .\ / | Með léttri lund verður | >>>> ,--' _,' | Dagurinn í dag | >>>> / / | Enn betri en gærdagurinn | >>>> ( -. | `-----------------------------------' >>>> | ) | (\_ _/) >>>> (`-. '--.) (='.'=) ♖♘♗♕♔♙ >>>> `. )----' (")_(") ☃☠ >>>> >>> >>> >>> >>> -- >>> Björn Helgason, Verkfræðingur >>> Fornustekkum II >>> 781 Hornafirði >>> Po Box 127,801 Selfoss , >>> t-póst: [email protected] >>> gsm: +3546985532 >>> sími: +3544781286 >>> http://groups.google.com/group/J-Programming >>> >>> >>> Tæknikunnátta höndlar hið flókna, sköpunargáfa er meistari einfaldleikans >>> >>> góður kennari getur stigið á tær án þess að glansinn fari af skónum >>> /|_ .-----------------------------------. >>> ,' .\ / | Með léttri lund verður | >>> ,--' _,' | Dagurinn í dag | >>> / / | Enn betri en gærdagurinn | >>> ( -. | `-----------------------------------' >>> | ) | (\_ _/) >>> (`-. '--.) (='.'=) ♖♘♗♕♔♙ >>> `. )----' (")_(") ☃☠ >>> >> >> >> >> -- >> Björn Helgason, Verkfræðingur >> Fornustekkum II >> 781 Hornafirði >> Po Box 127,801 Selfoss , >> t-póst: [email protected] >> gsm: +3546985532 >> sími: +3544781286 >> http://groups.google.com/group/J-Programming >> >> >> Tæknikunnátta höndlar hið flókna, sköpunargáfa er meistari einfaldleikans >> >> góður kennari getur stigið á tær án þess að glansinn fari af skónum >> /|_ .-----------------------------------. >> ,' .\ / | Með léttri lund verður | >> ,--' _,' | Dagurinn í dag | >> / / | Enn betri en gærdagurinn | >> ( -. | `-----------------------------------' >> | ) | (\_ _/) >> (`-. '--.) (='.'=) ♖♘♗♕♔♙ >> `. )----' (")_(") ☃☠ >> > > > > -- > Björn Helgason, Verkfræðingur > Fornustekkum II > 781 Hornafirði > Po Box 127,801 Selfoss , > t-póst: [email protected] > gsm: +3546985532 > sími: +3544781286 > http://groups.google.com/group/J-Programming > > > Tæknikunnátta höndlar hið flókna, sköpunargáfa er meistari einfaldleikans > > góður kennari getur stigið á tær án þess að glansinn fari af skónum > /|_ .-----------------------------------. > ,' .\ / | Með léttri lund verður | > ,--' _,' | Dagurinn í dag | > / / | Enn betri en gærdagurinn | > ( -. | `-----------------------------------' > | ) | (\_ _/) > (`-. '--.) (='.'=) ♖♘♗♕♔♙ > `. )----' (")_(") ☃☠ > -- Björn Helgason, Verkfræðingur Fornustekkum II 781 Hornafirði Po Box 127,801 Selfoss , t-póst: [email protected] gsm: +3546985532 sími: +3544781286 http://groups.google.com/group/J-Programming Tæknikunnátta höndlar hið flókna, sköpunargáfa er meistari einfaldleikans góður kennari getur stigið á tær án þess að glansinn fari af skónum /|_ .-----------------------------------. ,' .\ / | Með léttri lund verður | ,--' _,' | Dagurinn í dag | / / | Enn betri en gærdagurinn | ( -. | `-----------------------------------' | ) | (\_ _/) (`-. '--.) (='.'=) ♖♘♗♕♔♙ `. )----' (")_(") ☃☠ ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
