Maybe time to review http://www.jsoftware.com/help/dictionary/d232.htm?
"x|:y moves axes x to the tail end." Or were you asking a different question? Thanks, -- Raul On Fri, Jun 2, 2017 at 7:09 AM, Brian Schott <[email protected]> wrote: > So, a revised version of trim with (2 0 1&|:) does work as this example > shows. > But it must have been a coincidence that (0 1&|:) worked without currying > tess to (cp;._3)? > There stills seems something peculiar here. > > trimhbr =: tess&(cp ;._3)"2 &.(2 0 1&|:) > trimhbr i. 7 10 3 > 33 34 35 > 42 43 44 > 51 52 53 > > 123 124 125 > 132 133 134 > 141 142 143 > > > On Fri, Jun 2, 2017 at 6:51 AM, Raul Miller <[email protected]> wrote: > >> debug/dissect should explain the error, but unfortunately it errors out, >> itself. >> >> Still, hopefully this makes sense: >> >> 2 0 1&|: tess >> |index error >> | 2 0 1&|:tess >> >> -- >> Raul >> >> >> >> On Fri, Jun 2, 2017 at 5:42 AM, Brian Schott <[email protected]> >> wrote: >> > Bob, >> > >> > I found some interesting/surprising results by delving further into your >> > analysis. >> > >> > First, this looks like what Henry had in mind. >> > >> > tess cp;._3"2&.( 0 1&|:)i.7 10 3 >> > 33 34 35 >> > 42 43 44 >> > 51 52 53 >> > >> > 123 124 125 >> > 132 133 134 >> > 141 142 143 >> > >> > But even though the following two transposes seems identical there is a >> > later surprise. >> > >> > (2 0 1&|: -: 0 1&|:) i. 7 10 3 >> > 1 >> > >> > And here is an unexpected surprise. Why is this an error. >> > >> > tess cp;._3"2&.(2 0 1&|:)i.7 10 3 >> > |index error >> > | tess cp;._3"2&.(2 0 1&|:)i.7 10 3 >> > >> > Second, to return to the timing issue, Henry's approach does seem to be >> > (much) faster. >> > >> > trimhb =: tess&(cp ;._3)"2 &.(0 1&|:) >> > 100000 timespacex 'trimhb i. 7 10 3' >> > 2.84443e_5 31744 >> > 100000 timespacex 'trimalt i. 7 10 3' >> > 3.79653e_6 7040 >> > >> > Third, one more observation that is somewhat irrelevant, but neat, >> involves >> > the intelligence of the j interpreter in this case. Look at the >> > (intelligence of?) the last line below where the boxed portion is >> > translated to display in linear representation (provided 9!:3]5 is set). >> > >> > tr i. 7 10 3 >> > +-----------+ >> > |+---+-----+| >> > ||1 4|1 4 7|| >> > |+---+-----+| >> > +-----------+ >> > (tr i. 7 10 3)&{ >> > (<1 4;1 4 7)&{ >> > (tr i. 70 100 3)&{ >> > (<(1+3*i.23);1+3*i.33)&{ >> > >> > And thank you for the detailed explanation you provided. >> > >> > The beat goes on ... >> > ---------------------------------------------------------------------- >> > For information about J forums see http://www.jsoftware.com/forums.htm >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm >> > > > > -- > (B=) <-----my sig > Brian Schott > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
