I can¹t add to Dan¹s explanation at all, it is perfect. I would only mention that when I need to ³see² how I might wish to apply rank, I sometimes ³enclose on rank² first to break into the desired cells, then apply to each cell. I find it then easier to derive Dan²s solution for example...
'0'= ": example 0 0 0 0 1 1 0 0 0 0 0 0 1 0 1 0 0 0 0 0 1 0 1 0 0 0 0 0 0 1 1 0 0 0 0 0 0 1 0 1 0 0 0 0 0 <"1 '0'= ": example +---------+---------+---------+---------+ ... +---------+---------+ |0 0 0 0 1|1 0 0 0 0|0 0 1 0 1|0 0 0 0 0| ... |0 0 1 0 1|0 0 0 0 0| +---------+---------+---------+---------+ ... +---------+---------+ I.&.> <"1 '0'= ": example +-+-+---++---+-+-+---++ |4|0|2 4||0 2|4|0|2 4|| +-+-+---++---+-+-+---++ Which as Dan shows, is easier shortened to ... <@I. '0'=":example +-+-+---++---+-+-+---++ |4|0|2 4||0 2|4|0|2 4|| +-+-+---++---+-+-+---++ Hope this helps.../Rob On 26/06/08 9:54 AM, "Dan Bron" <[EMAIL PROTECTED]> wrote: > Tracy Harms wrote: >> > What I want instead of this is a list of boxes. Each box is >> > to contain the result of I. applied to the corresponding item >> > of example . > > What you want is <@I. '0'=":example . You don't want &.> because verbs > derived from it have rank zero, and I. doesn't make > sense on scalars ( I. needs to look at a whole list; I.&.> can only look > at an atom at a time). > > The reason <@I. works without needing the rank conjunction is because I. > is already rank one: > > I. b. 0 > 1 _ _ > > > If it weren't, you'd need the rank conjunction. For example, let's say I. > were instead defined with rank infinity: > > I =: I."_ > > then you'd need to say something along the lines of <@:I"1 '0'=":example . > Or, say you wanted to take advantage of the special > code which supports I.@:= . Then you'd need to say '0' <@:(I.@:=)"1 > example. > > Does that help? > > -Dan > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
