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 | ( -. | `-----------------------------------' | ) | (\_ _/) (`-. '--.) (='.'=) ♖♘♗♕♔♙ `. )----' (")_(") ☃☠ ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
