Newsgroups: comp.lang.apl
Apparently-to: DAN KELLEY
Subject: Availability of J Co
From: donald.mcintyre@almac.co.uk (Donald Mcintyre)
Distribution: world
Message-ID: <17.2063.525.0N6406B0@almac.co.uk>
Date: Fri, 22 Apr 94 18:15:00 +0000
Organization: ALMAC: Scotland : +44 (0)324 665371
Lines: 30

DK> I mean I don't know how to get J to read/write to the filesystem.
DK> For example, how would I do this task:

DK> 1) open a file (named "xy.dat", say) 2) read from it two columns,
DK> "x" and "y" 3) find the polynomial curvefit y = a0*x + a1*x + a2*x*x
DK> ...

DK> Note: I could figure part 3 out myself, if I could find how to read
DK> data into arrays in J.  What I mostly need to know is how to do IO.
DK> Obviously I'm missing something here!  Perhaps somebody could post
DK> the line or two it would take to accomplish steps 1 and 2 above?
DK> I'd appreciate it, and maybe other novices would also.

I published a tutorial intended to help people over this particular
hurdle in using J. Here is the reference:

     Using J with External Data
     VECTOR Vol.8 No.4 (April 1992) p.97-110
     ISSN 0955-1433

VECTOR, which is the Journal of the British APL Association, is the
main source for information on J other than Iverson Software's
publications.

This paper, along with my other tutorial papers and annotated J-scripts,
is on a disk which was distributed at APL93.  Anyone executing the
scripts and printing the results will have a book-length text of
examples.

 * RM 1.2 01091 * donald.mcintyre@almac.co.uk

