HDTenEightyP/NetNews huggingface dataset:
From:         pbid@ipsaint.ipsa.reuter.COM (Biddlecombe, Peter (london, Uki Pdg))
Subject:      Mock Morris
Reply-To:     pbid@ipsaint.ipsa.reuter.COM (Biddlecombe, Peter (london, Uki Pdg))
Organization: Reuters Information Services (Canada)
Date:          8 Jan 93 11:00:08 UT


-----------Message forwarded from IPSA Mailbox-------------


no. 6886198 filed 10.35.39  fri  8 jan 1993
from pbid
to   uclapl
cc   pbid@rmx
subj Mock Morris

To: funny@clarinet.com

Why can't circumcised men become morris dancers?

You have to be a complete prick to be a morris dancer.

(Morris dancers are those chaps with silly clothes and bells on their feet 
who provide such a delightful feature of English rustic life.)

This came to me from the pathology dept of Stoke Mandeville hospital where
my girlfriend works.


-----------------------------------------------------------
This posting is forwarded from an internal Reuters mailbox.
No statement or opinion contained herein should be taken as
being Reuters policy, or even as being approved by Reuters,
in any way.
Newsgroups: comp.lang.apl
From: sam@csi.jpl.nasa.gov (Sam Sirlin)
Subject: Re: Matrix Inverse in APL2
Originator: sam@kalessin
Organization: Jet Propulsion Laboratory, Pasadena, CA
Date: Tue, 12 Jan 1993 18:23:24 GMT


In article <C0puI4.Mv6@undergrad.math.waterloo.edu>, bdcrafto@cayley.uwaterloo.ca (Brad Crafton) writes:
|> HELP!!  For a project I'm doing for work I require a routine to take the
|> Inverse of a very large matrix (in the order of 1000x1000).  

You should be sure you really want the inverse and not a solution to a
linear system of equations. They are somewhat different problems.

|> The 
|> Matrix Inverse function tends to bomb out at even a 10x10 matrix.

Wow! What are you using? Must be pretty bogus. Is APL2 really that
unreliable? On all machines? What do you mean by bomb out... does it
complain about singularity, is the problem ill conditioned, and do you
know there really is an inverse that it doesn't find?

|> I am assuming that some sort of Gaussian Elimination routine is
|> needed.  Is there somewhere where I could find a pre-written routine?

The best routines for full matrices are in LINPACK or the newer
LAPACK. These are written in fortran and are available free over the
net (try archie... one of the ATT nodes I think has them). Note that
there are various simplifications depending on whether or not the
matrix is symmetric, complex, etc. The LINPACK manual should be in
you're library and you need to read it to understand more about what
you're doing. 

|> I realize that for a matrix so large, it would probably take a LONG
|> time to run.  But could anyone guestimate what kind of time I'm
|> looking at?  Minutes?  Hours?  If it means anything, most of the
|> entries in the matrix will be zero.

The inverse is (in general) an n^3 problem. So you can extrapolate for
you're machine. Sounds like you have a sparse system. I'm not familiar
with routines for such, but they do exist and are likely to be
enormously more efficient and accurate (try looking for sparspack or
something like it). The current matlab includes sparse stuff. Since
the complexity increases so fast, it should be obvious to you that
reducing the dimension could make a dramatic difference.

You're system is big enough that you should spend some time on this,
to make sure that the answers you get are not just garbage.

-- 
Sam Sirlin
Jet Propulsion Laboratory         sam@kalessin.jpl.nasa.gov

Newsgroups: comp.lang.apl
From: neitzel@ips.cs.tu-bs.de (Martin Neitzel)
Subject: wanted:  Foils for a J intro
Reply-To: neitzel@ips.cs.tu-bs.de
Organization: Inst. f. Informatik, TU Braunschweig, FRG
Date: Fri, 8 Jan 1993 14:59:51 GMT

I could take an occasion in the next days to offer a talk about J to
some folks here.  These people are typically engineers or chemists
doing some scientific computing in Fortran on a 3090 vector processor
mainframe.  (And are just coming into contact with powerful networked
workstations.)

If somebody has already outlined some luring foils for such occasions
and would be so kind to share them, I would appreciate that very much.
Suggestions / sketches are fine since I'll have to do the translation
and typesetting anyways.  Material doing this for APL is just as well.

Here's a tentative topic list, comments are welcome.

						Martin Neitzel

* J. Backus' opinion about traditional languages, one-at-a-time
  computing and APL out of his famous Turing award lecture.
* Suggestive examples in concrete J.
* J as a high-level language and its benefits for an underlying vector
  processor architecture.
* More examples.
* J as a portable language, utilising the entire spectrum of available
  develepment environments.

Btw, is anybody actively working on J implementations tailored to
vector processors?
Newsgroups: comp.lang.apl
From: weg@mace.cc.purdue.edu (Eythan Weg)
Subject: compiling j62
Organization: Purdue University
Distribution: comp
Date: Sat, 9 Jan 1993 16:49:46 GMT

Can someone tell what libcfix.a is, required to compile j6.2?  I
cannot find it on rs6000.

Thanks, Eythan
From: andrew@rentec.com (Andrew Mullhaupt)
Newsgroups: comp.lang.apl
Subject: Re: Matrix Inverse in APL2
Date: 12 Jan 93 20:25:45 GMT
Organization: Renaissance Technologies Corp., Setauket, NY.

In article <C0puI4.Mv6@undergrad.math.waterloo.edu> bdcrafto@cayley.uwaterloo.ca (Brad Crafton) writes:
>HELP!!  For a project I'm doing for work I require a routine to take the
>Inverse of a very large matrix (in the order of 1000x1000).  The 
>Matrix Inverse function tends to bomb out at even a 10x10 matrix.

That doesn't sound like APL2's fault. APL2 uses Householder QR with
column pivoting, so you may have a singular matrix in the 10x10 case,
in which case you might be best served by: 1. thinking about the matrix
to make sure it should have an inverse, 2. possibly using SVD to compute
the pseudo-inverse.

>I am assuming that some sort of Gaussian Elimination routine is
>needed.  Is there somewhere where I could find a pre-written routine?

There are lots of places, but you should not so quickly assume that
Gaussian elimination is a good idea.

>I realize that for a matrix so large, it would probably take a LONG
>time to run.  But could anyone guestimate what kind of time I'm
>looking at?  Minutes?  Hours?  If it means anything, most of the
>entries in the matrix will be zero.

You should probably take advantage of the large number of zeros, (in the
jargon you may have a 'sparse' matrix). The best thing there is to
skip using APL at all and find a routine which may be suited to your
particular matrix which can perhaps be used from within APL2. In order
to get more out of the Internet, you should probably post a non-APL
specific query with a reasonable description of your matrix problem to
sci.math.num-analysis. Two books you should get some handle on, although
you may need some elementary numerical analysis books before you can
get very far, are Golub and van Loan's _Matrix Computations_ and Hanson
and Lawson's _Solving Least Squares Problems_, although Golub and van
Loan mostly supercedes Hanson and Lawson.

Later,
Andrew Mullhaupt
Newsgroups: comp.lang.apl
From: hui@fid.morgan.com (Roger Hui)
Subject: Re: performance update, apologies offered
Keywords: performance, j
Organization: Morgan Stanley & Co., New York, NY
Date: Sat, 9 Jan 1993 01:12:48 GMT

Joseph Alotta writes:

> j is still some 37% slower, but i think the difference can be 
> partially accounted for by the fact that j allows complex numbers
> and z does not, and j allows n-dimensional arrays where z allows
> up to 3 dimensions.
> 
> amy{jja}15: cat ztest
> a=iota(1e6);
> +/a;
> amy{jja}16: cat jtest
> a=. i. 1e6
> +/a
> amy{jja}17: time zlang ztest
> 5.000005e+11
> 3.5u 0.8s 0:04 95% 0+0k 2+0io 0pf+0w
> amy{jja}18: time j < jtest
> 4.999995e11
> 2.2u 1.1s 0:03 96% 0+0k 0+0io 0pf+0w
> J6   Copyright (c) 1990-1992, Iverson Software Inc.  All Rights Reserved.
> 
>    1.1 % 0.8
> 1.375

It seems to me that this benchmark compares the time required to do 
the sum and to load/initialize the interpreters, and therefore may not 
necessarily reflect the relative performance of the two interpreters.
Newsgroups: comp.lang.apl
From: jja@fnbc.com (Joseph Alotta)
Subject: performance update, apologies offered
Keywords: performance, j
Organization: First National Bank Of Chicago, Chicago IL, USA
Date: Fri, 8 Jan 93 15:16:56 GMT


i retested j vs. z language and found the results to be much
more encouraging.

the following tests were made on the same machine with the j6,
(i had tested j5 earlier).

j is still some 37% slower, but i think the difference can be 
partially accounted for by the fact that j allows complex numbers
and z does not, and j allows n-dimensional arrays where z allows
up to 3 dimensions.

amy{jja}15: cat ztest
a=iota(1e6);
+/a;
amy{jja}16: cat jtest
a=. i. 1e6
+/a
amy{jja}17: time zlang ztest
5.000005e+11
3.5u 0.8s 0:04 95% 0+0k 2+0io 0pf+0w
amy{jja}18: time j < jtest
4.999995e11
2.2u 1.1s 0:03 96% 0+0k 0+0io 0pf+0w
J6   Copyright (c) 1990-1992, Iverson Software Inc.  All Rights Reserved.

   1.1 % 0.8
1.375

sorry for causing grief.  j is a super language and i want to 
thank those who have made it possible.


joe.


==============================================================
! joe alotta                                    jja@fnbc.com !                                               
!                                             (312) 732-3439 !
!                                                            !
! "The main thing is to keep the main thing the main thing." !
! Dr. George Sweeney                                         !
==============================================================
Newsgroups: comp.lang.apl
From: emclean@sfsuvax1.sfsu.edu (Emmett McLean)
Subject: Future enhancements to J <> Also, what is D. ?
Organization: San Francisco State University
Distribution: NA
Date: Tue, 5 Jan 1993 05:48:20 GMT

I am curious about the developments we might see in J in the
next year. Recently, infact, I called ISI and talked with
Eric Iverson.  He mentioned that they maintain a listing
of enhancements they'd like to make, each with an
estimate of implementation time and utility. For example,
a debugger is an item which someday we might see. Also, I would
like to know if we might see a slicker J-C C-J interface,
or perhaps see some code which might allow users on the PC to
call EXCELL via J as in Manuguistics APL. 

Also, what is D. in v6.2?

Thanks,

Emmett
Newsgroups: comp.lang.apl
From: qmdbms@gsusgi2.gsu.edu (Brian Schott)
Subject: Re: sorry, but a disappointing performance report
Keywords: performance,j
Organization: Georgia State University
Date: Wed, 6 Jan 1993 20:48:33 GMT

jja@fnbc.com (Joseph Alotta) writes:



>   a=. i. 1e7
>   +/a
>4.999995e11

>for the above, the z interpreter was an order of magnitude (10x) faster  
>than the j interpreter.

What release of j did you use? I understand it has been sped up of late.

>the person who wrote it, a very smart person, says he didn't do anything
>special or anything different than what a good c programmer would
>noramlly do.   my quick inspection of his source code proves this to be  
>true.

>the z interpreter is an order of magnitude slower than compiled c code, so  
>that means that j is 2 orders of magnitude (100x) slower than c.

>this raises the following questions:

>1.  can these results be verified by testing j against apl interpreters?

There is a timing primitive in j. Try:(100) 6!:2 <'+/a' to get the time
average of 100 executions.

>2.  can it be that j is doing additional work that z is not?

>3.  does anyone really care about the speed?

>4.  perhaps maybe someone should think about modifying to j interpreter
>to have it run faster.

>5.  i might be willing to take a look at it, if i could find the
>documentation.  as it is i can't make head or tails out of the code.

Documentation for the code is available for $90 from ISI in Canada.  It is
a terse, but IMHO, clear document. Also, Roger Hui has been awarded a
fellowship type of position by the ACM for the year 1993.  His travel to
sites in North America can be partially funded by the ACM.  He implemented
j and could probably motivate folks to enhance the code.

(B=)
Newsgroups: comp.lang.apl
From: jja@fnbc.com (Joseph Alotta)
Subject: sorry, but a disappointing performance report
Keywords: performance,j
Organization: First National Bank Of Chicago, Chicago IL, USA
Date: Tue, 5 Jan 93 19:02:33 GMT


greetings,

here at my company they have been using a apl-like interpreter
in production mode for about a year.  we'll call it z language to
avoid proprietary issues.

we did a test in both languages:

   a=. i. 1e7
   +/a
4.999995e11

for the above, the z interpreter was an order of magnitude (10x) faster  
than the j interpreter.

the person who wrote it, a very smart person, says he didn't do anything
special or anything different than what a good c programmer would
noramlly do.   my quick inspection of his source code proves this to be  
true.

the z interpreter is an order of magnitude slower than compiled c code, so  
that means that j is 2 orders of magnitude (100x) slower than c.

this raises the following questions:

1.  can these results be verified by testing j against apl interpreters?

2.  can it be that j is doing additional work that z is not?

3.  does anyone really care about the speed?

4.  perhaps maybe someone should think about modifying to j interpreter
to have it run faster.

5.  i might be willing to take a look at it, if i could find the
documentation.  as it is i can't make head or tails out of the code.


joe.


==============================================================
! joe alotta                                    jja@fnbc.com !                                               
!                                             (312) 732-3439 !
!                                                            !
! "The main thing is to keep the main thing the main thing." !
! Dr. George Sweeney                                         !
==============================================================
Newsgroups: comp.lang.apl
From: emclean@sfsuvax1.sfsu.edu (Emmett McLean)
Subject: (J) Simultaneous column assignment into a list
Organization: San Francisco State University
Distribution: NA
Date: Tue, 5 Jan 1993 04:16:11 GMT

 This is an inquiry for a verb allowing simultaneous 
 column assignment into a list. In pseudo code
 with bracket indexing, it is : (*see below for the
 pseudo code for a statisfactory alternative.)
 w 
9 7 7  6  1 6 8
2 4 7  4 20 2 3
1 4 8  9 40 9 5
 s
30  1 
50 20
90 40
 w[;3 4] =. s
 w
9 7 7 30  1 6 8
2 4 7 50 20 2 3
1 4 8 90 40 9 5

 Here's a solution but it's hardly elegant:

 ca =. >@{:@]`($@[ #. (i.@$@>@{: ,. >@{.)@])`[}
 ca1 =. >@}.@]`($@[ #. (i.@$@>@}. ,"0/ >@{.)@])`[} NB. column assign
 (BTW ca1 is another version of ca which works on v6.1 the NeXt but 
  yeilds a length error on v6.1 on the VAX)

 mca =. i. 0 0 NB. multiple column assign
 mca =. mca,'loop) $. =. > (0 = # y.) { cont ; end'
 mca =. mca,'cont) x. =. x. ca {. y.'
 mca =. mca,'y. =. }. y.'
 mca =. mca,'$. =. loop'
 mca =. mca,'end) y. =. x.'
 mca =.'': mca
 d =. ,: 3 ; 30 50 90
 ]d =. d, 4 ; 1 20 40
+-+--------+
|3|30 50 90|
+-+--------+
|4|1 20 40 |
+-+--------+
  w mca d
9 7 7 30  1 6 8
2 4 7 50 20 2 3
1 4 8 90 40 9 5

 *Actually, it might be more straight forward to cook up an
  alternative verb whose pseudo code is :

  w[;3 4] =. w[;3 4] + 1 2 3 ,. 4 5 10

  Thanks,
  Emmett
From: emclean@sfsuvax1.sfsu.edu (Emmett McLean)
Newsgroups: comp.lang.apl
Subject: Re: Efficient combinations verb
Date: 5 Jan 93 04:25:27 GMT
Distribution: NA
Organization: San Francisco State University

Hmm? I finally got a chance to try out Rogers comb and
comb1 verb on both the NeXT and the VAX and in each
instance I get an index error for m > 2.

    start =. i.@-.-
    count =. <:@[ ! <:@[ + |.@start
    index =. ;@:((i.-])&.>)
    recur =. (count#start) ,. (index@count{comb&.<:)
    test  =. *@[ *. <
    basis =. i.@(<: , [)
    comb  =. basis`recur @. test

    seed  =. *@[ i.@{ 1 0&,:@(,&1)@>:@(-~)
    em    =. >:@{:@$
    en    =. 2&+@{:@{:
    g     =. em (count#start) en
    h     =. em (index@count) en
    grow  =. g ,. h { >:
    comb1 =. [ grow@]^:(>{:@$) seed
Newsgroups:   comp.lang.apl
From:         eem@ipsaint.ipsa.reuter.COM (Mcdonnell, Eugene E.)
Subject:      adverse in J
Reply-To:     eem@ipsaint.ipsa.reuter.COM (Mcdonnell, Eugene E.)
Organization: Reuters Information Services (Canada)
Date:         10 Jan 93 05:00:05 UT


-----------Message forwarded from IPSA Mailbox-------------


no. 6889070 filed  4.54.37  sun 10 jan 1993
from eem
to   uclapl
subj adverse in J

  

Paul Moore (pmoore@cix.compulink.co.uk). asks what the meaning of 
u :: v is.  It is related to obverse, in the sense that either u 
or v is executed.  In fact, u :: v y is u y unless circumstances 
are adverse to u's successful execution, in which case the 
"adverse" verb v is executed.  Similarly for x u :: v y.  

The motivation for this language facility is to reduce the 
occasions when quoted strings are required in J.  Compare it with 
"do left if error" (".), whose arguments are required to be 
character lists, with all the resulting nastinesses familiar to 
those who have used the execute primitive in APL systems -- or 
the execute alternate system function in APL2. 


-----------------------------------------------------------
This posting is forwarded from an internal Reuters mailbox.
No statement or opinion contained herein should be taken as
being Reuters policy, or even as being approved by Reuters,
in any way.
Newsgroups: comp.lang.apl
From: bdcrafto@cayley.uwaterloo.ca (Brad Crafton)
Subject: Matrix Inverse in APL2
Organization: University of Waterloo
Date: Tue, 12 Jan 1993 00:54:03 GMT

HELP!!  For a project I'm doing for work I require a routine to take the
Inverse of a very large matrix (in the order of 1000x1000).  The 
Matrix Inverse function tends to bomb out at even a 10x10 matrix.

I am assuming that some sort of Gaussian Elimination routine is
needed.  Is there somewhere where I could find a pre-written routine?

I realize that for a matrix so large, it would probably take a LONG
time to run.  But could anyone guestimate what kind of time I'm
looking at?  Minutes?  Hours?  If it means anything, most of the
entries in the matrix will be zero.


Any help would be appreciated!

Brad.

-- 
-----
Brad Crafton                            bdcrafton@descartes.UWaterloo.CA
3B Actuarial Science, University of Waterloo, Waterloo, Ontario, Canada.
Newsgroups:   comp.lang.apl
From:         pbid@rmx@ipsaint.ipsa.reuter.COM (Remote Addressee:)
Subject:      egg on face
Reply-To:     pbid@rmx@ipsaint.ipsa.reuter.COM (Remote Addressee:)
Organization: Reuters Information Services (Canada)
Date:          8 Jan 93 14:00:04 UT


-----------Message forwarded from IPSA Mailbox-------------


no. 6886485 filed 13.27.08  fri  8 jan 1993
from pbid@rmx
to   uclapl
cc   loc
subj egg on face

@transferred from rmx  no. 100135 filed 13.26.59  fri  8 jan 1993

My recent post on morris dancers was mis-directed. Apologies.


-----------------------------------------------------------
This posting is forwarded from an internal Reuters mailbox.
No statement or opinion contained herein should be taken as
being Reuters policy, or even as being approved by Reuters,
in any way.
From: z_youngwd@ccsvax.sfasu.edu
Newsgroups: comp.lang.apl
Subject: fonts for APL
Date: 5 Jan 93 20:13:49 CST
Organization: Stephen F. Austin State University

I hope this is not a FAQ...

Are there any fonts for APL characters available as windows
true type fonts?  If not, are there any that can be downloaded
to an hp printer.  

Just FYI:  I want to write handbook for work... and I am tired
of handwriting symbols.

Thanks.

Wayne


Newsgroups: comp.lang.apl
From: neitzel@ips.cs.tu-bs.de (Martin Neitzel)
Subject: J literature
Reply-To: neitzel@ips.cs.tu-bs.de
Organization: Inst. f. Informatik, TU Braunschweig, FRG
Date: Fri, 8 Jan 1993 15:20:51 GMT

Some months ago I commented on my experience with ISI's J literature
which has been further extended now.

If you've been as frustrated by "Programming in J" as a first course
as I was, but were able manage the later written "Introduction", you
should consider to give the PiJ a second stab.  I was surprised how
accessible it is now to me.

						Martin Neitzel
Newsgroups: comp.lang.apl
From: sam@csi.jpl.nasa.gov (Sam Sirlin)
Subject: Re: fonts for APL
Originator: sam@kalessin
Organization: Jet Propulsion Laboratory, Pasadena, CA
Date: Wed, 6 Jan 1993 18:50:17 GMT


In article <1993Jan5.201349.2334@ccsvax.sfasu.edu>, z_youngwd@ccsvax.sfasu.edu writes:
|> I hope this is not a FAQ...

Hmm, I suppose there should be at least a line about this...

|> Are there any fonts for APL characters available as windows
|> true type fonts?  If not, are there any that can be downloaded
|> to an hp printer.  
|> 
|> Just FYI:  I want to write handbook for work... and I am tired
|> of handwriting symbols.

I'm sure there are since Manugistics [STSC] (at least) have a windows
product. Probably not free though... 

There are both TeX and X fonts available on waterloo. TeX stuff can be
put into postscript (TeX's all I think I'll ever use for writing stuff
now: portable, free, beautiful output, can you write Quenya in 
anything else?). TeX isn't for the faint of heart though (nor is APL I
suppose). 

-- 
Sam Sirlin
Jet Propulsion Laboratory         sam@kalessin.jpl.nasa.gov
From: test@aix3.bgs.com (A test account)
Newsgroups: comp.lang.apl
Subject: test
Date: 5 Jan 1993 17:40:14 -0500
Organization: BGS Systems
NNTP-Posting-Host: aix3.bgs.com

test test
Newsgroups: comp.lang.apl
From: hui@fid.morgan.com (Roger Hui)
Subject: Re: compiling j62
Organization: Morgan Stanley & Co., New York, NY
Date: Sat, 9 Jan 1993 19:26:15 GMT

Eythan Weg writes:

> Can someone tell what libcfix.a is, required to compile j6.2?  I
> cannot find it on rs6000.

On UNIX machines other than those using the University of Waterloo 
MFCF library organization, the phrase   cc *.o -lm -o j   links the
object files *.o with the math library m to produce the executable "j".  
cfix is not required.
Newsgroups: comp.lang.apl
From: pmoore@cix.compulink.co.uk (Paul Moore)
Subject: Useful features in recent versions of J
Reply-To: pmoore@cix.compulink.co.uk
Date: Wed, 6 Jan 1993 21:16:00 +0000

As I still only have the J dictionary for version 4 (the version 5
one is on its way - when is the version 6 dictionary due out?), but
I have J 6.2 and the sources for 6.2, I decided to do some
experimenting. The results have uncovered some interesting new
features implemented since 4.1.

    {.!.f       Take, but use f as the "fill value" for overtakes.
    [: and ]:   Adverbs like [,] and [.,]. - ie v ]: is v.
    u b.        A monadic verb which can only take one of 0, 1
                and -1 as arguments
                   (u b.) 0    ==>   The ranks of u
                   (u b.) 1    ==>   The identity for u
                   (u b.) -1   ==>   The inverse of u
                The latter 2 are linear representations, the first
                is a 3-element numeric list.

This one (u b.) answers a question I asked recently, on how to find
the ranks of a verb. Thanks, Roger!

Also, have a look at D., introduced in 6.2. For any monadic verb v,
(v D. n) is the verb which is the nth derivative of v. This is very
powerful stuff! (For now, n >= 0, but n < 0 gives a nonce error - is
the intention to add integration at a later date?)

Finally, one I cannot work out. Can anybody tell me what (u :: v) is?
The source calls it "adverse" - presumably related to "obverse" in
some way. Can anyone help? Otherwise, I will have to wait for a J 6
dictionary to be written, and to make its way to the UK :-(

Paul Moore (pmoore@cix.compulink.co.uk).