You might also be interested in the inverse of copy 1 0 0 0 1 0 1 #^:_1 'abc'
a b c I remember I had a hard time finding expand On Fri, Apr 16, 2021 at 1:53 AM ethiejiesa via Programming < [email protected]> wrote: > Is monadic # what you're looking for? > > mask # chars > BEG > > HH PackRat <[email protected]> wrote: > > Hello, all! > > > > I have a list of characters and a boolean list of 1s and 0s. I > > thought that I could use the boolean list as a "mask" to choose > > characters by using "and" (*.). But the definition in NuVoc basically > > states that it can only be used with numbers (no literals). > > > > Here's an example of the kind of thing I'd like to be able to do: > > > > chars=. 'ABCDEFGHIJKLM' > > mask=. 0 1 0 0 1 0 1 0 0 0 0 0 0 [boolean values] > > > > mask2=. 0 1 0 0 4 0 6 0 0 0 0 0 0 [positions of boolean values] > > > > I thought that I could do something like chars *. mask to get the > > result BEG. That doesn't work nor does converting the mask to > > position numbers (mask2) work. So how *can* I mask the characters? > > I'd be interested in knowing both the "pure" boolean kind of approach > > (1s and 0s only) as well as a positional approach that I can use with > > amending. > > > > My ultimate goal is actually to amend the masked characters to be a > > different character(s). I hope I've given enough information. (The > > example, of course, is completely "fake", but I hope it gives the idea > > of what I'm trying to do.) > > > > Thanks for any help! > > > > Harvey > > ---------------------------------------------------------------------- > > 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
