I'm not sure just how = goes about comparing boxed data, but opening the boxes can be avoided by: */"1 a:=a 0 1 0
On Tue, May 31, 2016 at 11:48 PM, bill lam <[email protected]> wrote: > step by step example. > > ] a=. a: (<1)} <"0 i. 3 5 > +--+--+--+--+--+ > |0 |1 |2 |3 |4 | > +--+--+--+--+--+ > | | | | | | > +--+--+--+--+--+ > |10|11|12|13|14| > +--+--+--+--+--+ > (0=#) &> a NB.test for empty in each cell > 0 0 0 0 0 > 1 1 1 1 1 > 0 0 0 0 0 > *./ (0=#) &> a NB. closed but not what we wanted > 0 0 0 0 0 > *./"1 (0=#) &> a NB. this work with rank operator > 0 1 0 > *./ |: (0=#) &> a NB. transpose also work > 0 1 0 > > The key is the adverb &> which open each cell, do something, then > assemble again. It also works if you have a more complicated > verb instead of tacit (0=#), eg > > foo=: 3 : 0 > if. #y do. 1 else. 0 end. > ) > > and then proceed with > foo &> a > > > Ср, 01 июн 2016, PR PackRat написал(а): > > I need to perform a certain action if an entire row in a transposed > > table (i.e., originally a column) has empty values, that is, all boxed > > data are the equivalent of a: or ''. The result should be a Boolean > > value--"true" meaning that the entire row has empty values. (A > > typical application would be old stock market data, where all of the > > "Open" values might be null or empty.) > > > > I don't know how to even begin writing such code (without a for/next > > loop to separately evaluate each box's value, a very non-J way of > > doing it). Please help. Thanks in advance! > > > > > > Harvey > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > > -- > regards, > ==================================================== > GPG key 1024D/4434BAB3 2008-08-24 > gpg --keyserver subkeys.pgp.net --recv-keys 4434BAB3 > gpg --keyserver subkeys.pgp.net --armor --export 4434BAB3 > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
