Thanks Henry, I woke up this morning realizing that the argument to & could be any value and that cleared up a lot of my fuzziness on what was going on. Thank you to Pascal as well for the explanation and Roger for twisting my brain for a few hours.
operand =. 2 2 2 $ 3 2 2 3 2 3 3 2 bitmask =. 2 2 2 $ 1 0 0 1 0 1 1 0 operator =. >: bitmask 0&(] operator) operand NB. original 4 3 3 4 3 4 4 3 bitmask 10&(] operator) operand NB. 10& same result 4 3 3 4 3 4 4 3 bitmask ' '&(] operator) operand NB. type is not even important - ' '& works 4 3 3 4 3 4 4 3 For efficiency, I don't see much difference between the two with these particular values 1000 timespacex ' bitmask 0&(] operator)"0 operand' 1.013e_6 2816 1000 timespacex 'bitmask (operator@]^:[)"0 operand' 9.38e_7 2816 But the much simpler addition of the bitmask to the operand is 3 times faster and takes up half the space. 1000 timespacex 'bitmask + operand' 3.14e_7 1408 bitmask + operand 4 2 2 4 2 4 4 2 Cheers, bob > On Aug 17, 2020, at 07:20, Henry Rich <henryhr...@gmail.com> wrote: > > In the example above, the 0& could be any value and is used only as a way of > getting the power function. ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
