Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!zaphod.mps.ohio-state.edu!wuarchive!udel!haven!umd5!suns.UMD.EDU!jph
From: jph@suns.UMD.EDU (J. Patrick Harrington)
Newsgroups: comp.lang.apl
Subject: Dyalog APL questions
Message-ID: <7258@umd5.umd.edu>
Date: 7 Sep 90 05:40:44 GMT
Sender: news@umd5.umd.edu
Reply-To: jph@suns.UMD.EDU (J. Patrick Harrington)
Organization: Univ. of Maryland @ College Park, Astronomy
Lines: 32


    I  have  recently  obtained Dyalog APL for one of our  Sun  4 
computers,   and  it  is  indeed  an  impressive  implementation, 
especially  after  limping  along with a  bug-ridden  version  of 
APL\11.  One  of  the problems with APL is that it seems to be  a 
universe  unto itself,  and little consideration is given to  the 
possibility of interfacing it with other languages/data sets that 
may reside on the system. One great feature of Dyalog APL is that 
interaction possible using "Auxiliary Processors"; in particular, 
the  'unixfiles' AP lets you read a native unix file outside  the 
APL workspace.
    I  very  soon found that I wanted to make  some  calculations 
based  on some data sets - columns of floating numbers - which  I 
had  in non-APL files on the system,  and I surely didn't want to 
type them in.  Well,  'unixfiles' would read them in,  but in the 
form of nested arrays of characters.  I could disclose and decode 
the  strings of characters to get numeric data - but  then  there 
were  the  '-'  signs!  Another AP called 'xutils'  contains  the 
function  'ss'  which searches out and replaces  strings.  So  we 
replace each '-' with the high minus,  and the 'e's with 'E's. So 
I  wrote  a little function that reads in a named unix  file  and 
turns  it  into a APL numeric array.  But it still hangs  on  the 
occasional '0.000E+00' it may find in the unix file.   
    I would think that reading lists of numbers from files  would 
be  such a basic need that others must have solved this  problem. 
Is there some neat way to do this?
    Another  question  for  those who may be  using  Dyalog:  Our 
printers  are  Apple LaserWriter II's,  which isn't  one  of  the 
supported  printers.   Does  anyone  have  experience  with  this 
combination? 
                                       J. Patrick Harrington
                                       jph@astro.umd.edu