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
