Newsgroups: comp.lang.apl
Path: watmath!watserv1!torn!utcsri!rpi!usc!wupost!uunet!trirex!root
From: trirex!taff@uunet.uu.net (Tom Affinito)
Subject: Re: J table question
Message-ID: <1992Jul24.145709.2154@Trirex.COM>
Sender: root@Trirex.COM (Operator)
Reply-To: trirex!taff@uunet.uu.net
Organization: Trirex Systems Inc.
References: <qmdbms.711902900@gsusgi1.gsu.edu>
Distribution: na
Date: Fri, 24 Jul 1992 14:57:09 GMT
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In article <qmdbms.711902900@gsusgi1.gsu.edu> qmdbms@gsusgi2.gsu.edu  
(Brian Schott) writes:
> But I am running into a problem because the result of x [/ y
> is a vector, not a table.  That surprises me since x */ y
> is a table.  Is this as it should be in J?
> 

I think this is a verb rank question.  Try 
x ["0 0 / y
and you'll get a table.  / uses the inserted verb's rank to determine the  
cells that are inserted-between (sic).  * has a dyadic rank of (0 0), so  
the numbers are inserted-between and you get a table.  ] is dyadic rank (_  
_), so the lists themselves are the units that are inserted-between.  The  
rank conjunction in the above sentence changes all that.

[of course until someone tells me why * has a monadic rank of _ I don't  
REALLY understand verb rank!]
tentatively,
Tom
trirex!taff@uunet.uu.net
