Here's an example of how I frequently use non-truth-valued # 9!:7]9 1 1#'+|-'
Thanks, -- Raul On Thu, Sep 11, 2014 at 6:49 AM, Dan Bron <[email protected]> wrote: > Note also that you can use plain, uninverted # to expand arguments: > > 1 1j1 1 (#!.1) 3 3 $ 0 > 0 0 0 > 0 0 0 > 1 1 1 > 0 0 0 > 1 1j1 1 (#!.1"1) 3 3 $ 0 > 0 0 1 0 > 0 0 1 0 > 0 0 1 0 > > > Which approach you pick often depends on whether it's easier for you to > express your expansion vector with length N (complex numbers) or N+1 > (boolean numbers). > > -Dan > > This is worth remembering as well, though I rarely see it used: > > 1 2 1 # i. 3 3 > 0 1 2 > 3 4 5 > 3 4 5 > 6 7 8 > > Please excuse typos; sent from a phone. > > > On Sep 11, 2014, at 5:32 AM, Raul Miller <[email protected]> wrote: > > > > Here are some perhaps relevant examples: > > > > 1 1 0 1 #inv (3 3$ 0) > > 0 0 0 > > 0 0 0 > > 0 0 0 > > 0 0 0 > > 1 1 0 1 #inv!.1 (3 3$ 0) > > 0 0 0 > > 0 0 0 > > 1 1 1 > > 0 0 0 > > 1 1 0 1 #inv!.1"1 (3 3$ 0) > > 0 0 1 0 > > 0 0 1 0 > > 0 0 1 0 > > 1 1 0 1 #inv!.1"1 (1 1 0 1) #inv!.1 (3 3$ 0) > > 0 0 1 0 > > 0 0 1 0 > > 1 1 1 1 > > 0 0 1 0 > > 1 1 0 1 # 1 1 0 1 #inv!.1"1 (1 1 0 1) #inv!.1 (3 3$ 0) > > 0 0 1 0 > > 0 0 1 0 > > 0 0 1 0 > > 1 1 0 1 #("1) 1 1 0 1 # 1 1 0 1 #inv!.1"1 (1 1 0 1) #inv!.1 (3 3$ 0) > > 0 0 0 > > 0 0 0 > > 0 0 0 > > (i.3) 2} 1 1 0 1 #inv (3 3$0) > > 0 0 0 > > 0 0 0 > > 0 1 2 > > 0 0 0 > > (i.4) 2}"0 1 (1 1 0 1) #inv"1 (i.3) 2} 1 1 0 1 #inv (3 3$0) > > 0 0 0 0 > > 0 0 1 0 > > 0 1 2 2 > > 0 0 3 0 > > (i.4) 2}"0 1 (1 1 0 1) #inv"1 (0 1 3) 2} 1 1 0 1 #inv (3 3$0) > > 0 0 0 0 > > 0 0 1 0 > > 0 1 2 3 > > 0 0 3 0 > > > > The whole #inv thing is a bit quirky but was quite deliberate. This was a > > primitive in APL, but the syntax was ... strange. Rather than trying to > > find a special symbol for this operation, Iverson put it on #inv (since - > > logically speaking - it's the inverse of #). > > > > Thanks, > > > > -- > > Raul > > > > > >> On Thu, Sep 11, 2014 at 5:21 AM, Sebastian <[email protected]> wrote: > >> > >> Hi, > >> > >> I know the verbs , ,. ,: to add rows, columns and dimensions to > matrices. > >> It is easy to add these to begin or the end of the corrosponding > dimension, > >> but what is to do, if I want to add one row/column in the middle of a > >> matrix? Is the only way to slice the matrix in two pieces and join them > >> with the new row/column? > >> > >> A few examples: > >> > >> Initial situation: > >> > >> 3 3 $ 0 > >> 0 0 0 > >> > >> 0 0 0 > >> > >> 0 0 0 > >> > >> > >> add column somewhere to the middle: > >> > >> 0 0 1 0 > >> > >> 0 0 1 0 > >> > >> 0 0 1 0 > >> > >> > >> > >> add row somewhere to the middle: > >> > >> 0 0 1 0 > >> > >> 0 0 1 0 > >> > >> 1 1 1 1 > >> > >> 0 0 1 0 > >> > >> > >> remove the added column: > >> > >> 0 0 0 > >> > >> 0 0 0 > >> > >> 1 1 1 > >> > >> 0 0 0 > >> > >> > >> > >> and the row: > >> > >> > >> > >> 0 0 0 > >> > >> 0 0 0 > >> > >> 0 0 0 > >> > >> > >> > >> Can anyone help me with this? > >> > >> > >> > >> Regards > >> > >> Sebastian > >> ---------------------------------------------------------------------- > >> 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
