The essay itself is important. The collected defintions are very short, I prefer to put them into the stdlib of base library if there are no objections.
Ср, 06 янв 2016, Anssi Seppälä написал(а): > Thank you all. This kind of data structure in J has a lot of power and > potential. Especially when the data is big. Jd database supports this. Bill > mentions an article with a set of definitions. I got from Chris a bit > different definition set. It would be nice to have a summary of this > technology and further standardize inverted tables in J library. These > definitions are not so easy to find by yourself as it shows below: > > a > +--------+--------+------+------------------+--------+--------+ > |20160104|1003005 |SEY |300511379 |20140314|20150401| > |20160104|1003006 |SEY |300533247 |20140429|20151112| > |20160104|1003012 |VF |6002894281 |20140401|20150904| > +--------+--------+------+------------------+--------+--------+ > b > +--------+--------+------+------------------+--------+--------+ > |20160104|1013327 |VF |6002924680 |20140403|20160102| > |20160104|1015127 |EONS |146149 |20090514|20150801| > |20160104|1042009 |ISS |201509245169 |20151010|20151201| > |20160104|1046107 |FE |14545413 |20150527|20160101| > |20160104|1103401 |FE |14419077 |20140206|20160101| > +--------+--------+------+------------------+--------+--------+ > a,&.>b NB. This is Roger's solution and does what I want > +--------+--------+------+------------------+--------+--------+ > |20160104|1003005 |SEY |300511379 |20140314|20150401| > |20160104|1003006 |SEY |300533247 |20140429|20151112| > |20160104|1003012 |VF |6002894281 |20140401|20150904| > |20160104|1013327 |VF |6002924680 |20140403|20160102| > |20160104|1015127 |EONS |146149 |20090514|20150801| > |20160104|1042009 |ISS |201509245169 |20151010|20151201| > |20160104|1046107 |FE |14545413 |20150527|20160101| > |20160104|1103401 |FE |14419077 |20140206|20160101| > +--------+--------+------+------------------+--------+--------+ > a,:b NB. I unsuccessfully tried this and many variations > +--------+--------+------+------------------+--------+--------+ > |20160104|1003005 |SEY |300511379 |20140314|20150401| > |20160104|1003006 |SEY |300533247 |20140429|20151112| > |20160104|1003012 |VF |6002894281 |20140401|20150904| > +--------+--------+------+------------------+--------+--------+ > |20160104|1013327 |VF |6002924680 |20140403|20160102| > |20160104|1015127 |EONS |146149 |20090514|20150801| > |20160104|1042009 |ISS |201509245169 |20151010|20151201| > |20160104|1046107 |FE |14545413 |20150527|20160101| > |20160104|1103401 |FE |14419077 |20140206|20160101| > +--------+--------+------+------------------+--------+--------+ > > ---------------------------------------------------------------------- > 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
