Array Oriented interpretation of Classical Algorithms 
Author Message
 Array Oriented interpretation of Classical Algorithms

I am a green horn APL/J learner wanna be.
I realised as I started working with the language that loops tend to
be a big no no and in APL there wasn't much by way of branching... I
was wondering if there were any pointers/papers etc available to
direct one in 'array oriented thinking' such that given a classical
algorithm containing loops and conditionals, an array oriented
interpretation could be given for it.
In short, how to think of loops and branching in terms of arrays.

The second question I have is an inquiry to the mathematical nature of
arrays. Exactly where did they emerge from and how are they used in
mathematics? I heard rumors of Tensor something but *shrug*

I am a newbie, I have never programmed, and I know quite a few people
would tell me to go learn python/perl/etc... but I am trying to learn
the apl/j language. I want to 'Think Different' (tm).



Tue, 20 Jan 2004 00:44:25 GMT  
 Array Oriented interpretation of Classical Algorithms
I, for one, would like to know what your name is, my impression is that you
are pulling our legs.

Fred

Quote:

> I am a green horn APL/J learner wanna be.
> I realised as I started working with the language that loops tend to
> be a big no no and in APL there wasn't much by way of branching... I
> was wondering if there were any pointers/papers etc available to
> direct one in 'array oriented thinking' such that given a classical
> algorithm containing loops and conditionals, an array oriented
> interpretation could be given for it.
> In short, how to think of loops and branching in terms of arrays.

> The second question I have is an inquiry to the mathematical nature of
> arrays. Exactly where did they emerge from and how are they used in
> mathematics? I heard rumors of Tensor something but *shrug*

> I am a newbie, I have never programmed, and I know quite a few people
> would tell me to go learn python/perl/etc... but I am trying to learn
> the apl/j language. I want to 'Think Different' (tm).



Tue, 20 Jan 2004 02:07:15 GMT  
 Array Oriented interpretation of Classical Algorithms
If you have never programmed it is quite unfruitful to talk
about algorithms and programming languages in the abstract.
To get a taste, go to the J website http://www.jsoftware.com ,
download and install J.  Start it and go through the Primer
(under "Help" on the main menu).

I can give you references to some books/papers after you
get a taste.

Quote:
----- Original Message -----


Sent: Thursday, August 02, 2001 10:34 AM
Subject: Array Oriented interpretation of Classical Algorithms


> I am a green horn APL/J learner wanna be.
> I realised as I started working with the language that loops tend to
> be a big no no and in APL there wasn't much by way of branching... I
> was wondering if there were any pointers/papers etc available to
> direct one in 'array oriented thinking' such that given a classical
> algorithm containing loops and conditionals, an array oriented
> interpretation could be given for it.
> In short, how to think of loops and branching in terms of arrays.

> The second question I have is an inquiry to the mathematical nature of
> arrays. Exactly where did they emerge from and how are they used in
> mathematics? I heard rumors of Tensor something but *shrug*

> I am a newbie, I have never programmed, and I know quite a few people
> would tell me to go learn python/perl/etc... but I am trying to learn
> the apl/j language. I want to 'Think Different' (tm).



Tue, 20 Jan 2004 02:57:49 GMT  
 Array Oriented interpretation of Classical Algorithms

Quote:

> If you have never programmed it is quite unfruitful to talk
> about algorithms and programming languages in the abstract.
> To get a taste, go to the J website http://www.jsoftware.com ,
> download and install J.  Start it and go through the Primer
> (under "Help" on the main menu).

> I can give you references to some books/papers after you
> get a taste.

Thank you. I have already started.

gilbert



Tue, 20 Jan 2004 07:26:18 GMT  
 Array Oriented interpretation of Classical Algorithms
The best advice I ever got on the "APL way of thinking" vs.
non-array-based approaches was from my professor in a Programming
Languages course at college: "In most programming languages, you write the
program to fit the data. In APL, you rearrange the data to fit the
program."

Suitable for stitching on a sampler, of course, but all in all a pretty
concise summary of APL et. al. vs. "traditional" languages.

/Chris Lett

Quote:

> I am a green horn APL/J learner wanna be.
> I realised as I started working with the language that loops tend to
> be a big no no and in APL there wasn't much by way of branching... I
> was wondering if there were any pointers/papers etc available to
> direct one in 'array oriented thinking' such that given a classical
> algorithm containing loops and conditionals, an array oriented
> interpretation could be given for it.
> In short, how to think of loops and branching in terms of arrays.



Wed, 28 Jan 2004 02:01:35 GMT  
 Array Oriented interpretation of Classical Algorithms


Quote:
>The best advice I ever got on the "APL way of thinking" vs.
>non-array-based approaches was from my professor in a Programming
>Languages course at college: "In most programming languages, you write the
>program to fit the data. In APL, you rearrange the data to fit the
>program."

>Suitable for stitching on a sampler, of course, but all in all a pretty
>concise summary of APL et. al. vs. "traditional" languages.

Not in my experience it ain't.

I didn't know Verizon had a branch office in Norway.

Quote:

>/Chris Lett


>> I am a green horn APL/J learner wanna be.
>> I realised as I started working with the language that loops tend to
>> be a big no no and in APL there wasn't much by way of branching... I
>> was wondering if there were any pointers/papers etc available to
>> direct one in 'array oriented thinking' such that given a classical
>> algorithm containing loops and conditionals, an array oriented
>> interpretation could be given for it.
>> In short, how to think of loops and branching in terms of arrays.

--
John Sullivan

Huh? Where did my sig go?



Wed, 28 Jan 2004 02:18:26 GMT  
 Array Oriented interpretation of Classical Algorithms

Quote:

>I am a green horn APL/J learner wanna be.
>I realised as I started working with the language that loops tend to
>be a big no no and in APL there wasn't much by way of branching... I
>was wondering if there were any pointers/papers etc available to
>direct one in 'array oriented thinking' such that given a classical
>algorithm containing loops and conditionals, an array oriented
>interpretation could be given for it.
>In short, how to think of loops and branching in terms of arrays.

>The second question I have is an inquiry to the mathematical nature of
>arrays. Exactly where did they emerge from and how are they used in
>mathematics? I heard rumors of Tensor something but *shrug*

Look at my paper in APL81 proceedings.  I believe the title was
'APL Thinking' (hey it's been 20 years and my APL stuff is out in
the garage in boxes).  The principles are still valid for the various
array oriented languages that have come out since classic APL.
/Bob
--
Robert Metzger           | TEL (972) 497-4437 | 3000 Waterview Parkway
Scalable Computing Lab   | FAX (972) 497-4245 | P.O. Box 833851        



Wed, 28 Jan 2004 03:32:56 GMT  
 Array Oriented interpretation of Classical Algorithms

Quote:

> >I am a green horn APL/J learner wanna be.
> >I realised as I started working with the language that loops tend to
> >be a big no no and in APL there wasn't much by way of branching... I
> >was wondering if there were any pointers/papers etc available to
> >direct one in 'array oriented thinking' such that given a classical
> >algorithm containing loops and conditionals, an array oriented
> >interpretation could be given for it.
> >In short, how to think of loops and branching in terms of arrays.

> Look at my paper in APL81 proceedings.  I believe the title was
> 'APL Thinking' (hey it's been 20 years and my APL stuff is out in
> the garage in boxes).  The principles are still valid for the various
> array oriented languages that have come out since classic APL.

The title is "APL Thinking -- Finding an Array-Oriented Solution".  pp. 212-218
in the Proceedings.  I'll try to find some time to (re)read it this weekend,
and then maybe give some comments my own.

Unfortunately, the copies of Proceedings from the APL Conferences which are
available on the ACM web site only go back to 1985.  Also in the 1981
Proceedings is a paper that should be pertinent to another recent thread:  "A
Regular Expression Pattern Matching Processor for APL" (pp. 94-100), by Mark R.
Dempsey and Leslie H. Goldsmith.



Wed, 28 Jan 2004 14:42:45 GMT  
 Array Oriented interpretation of Classical Algorithms

Quote:


> >I am a green horn APL/J learner wanna be.

            [etc.]

Where's the full original of g's message?  I didn't see it in the NG, and I
don't find it in searching Google's groups, either.  There the Metzger post is
the only one I find in that thread.

(Actually, the entire NG seems to have been flushed while I was away for a
couple of days.  Was that a general thing, or just my local news server?)

            /Jim Lucas



Wed, 28 Jan 2004 15:34:06 GMT  
 Array Oriented interpretation of Classical Algorithms

Quote:

> > >I am a green horn APL/J learner wanna be.

>             [etc.]

> Where's the full original of g's message?  I didn't see it in the NG, and I
> don't find it in searching Google's groups, either.  There the Metzger post
is
> the only one I find in that thread.

I tried again, searching a different way, and got 7 messages in the thread,
including the original.  I guess Google's search engine has some holes in it.

                /Jim



Wed, 28 Jan 2004 15:41:01 GMT  
 Array Oriented interpretation of Classical Algorithms

|The best advice I ever got on the "APL way of thinking" vs.
|non-array-based approaches was from my professor in a Programming
|Languages course at college: "In most programming languages, you write the
|program to fit the data. In APL, you rearrange the data to fit the
|program."

I'd have said that in APL you rearrange the data to fit the *problem*;
if you do this correctly, the program will practically write itself.

Eric Landau, APL Solutions, Inc.
"Sacred cows make the tastiest hamburger." - Abbie Hoffman



Fri, 30 Jan 2004 19:49:41 GMT  
 Array Oriented interpretation of Classical Algorithms

Quote:

>> Look at my paper in APL81 proceedings
>The title is "APL Thinking -- Finding an Array-Oriented Solution".  pp.
212-218
>in the Proceedings.  I'll try to find some time to (re)read it this
weekend,
>and then maybe give some comments my own.

>Unfortunately, the copies of Proceedings from the APL Conferences which are
>available on the ACM web site only go back to 1985.  Also in the 1981
>Proceedings is a paper that should be pertinent to another recent thread:
"A
>Regular Expression Pattern Matching Processor for APL" (pp. 94-100), by
Mark R.
>Dempsey and Leslie H. Goldsmith.

Proceedings will be added to the ACM digital library further back than this,
but I can not promise when they will be up.  According to current SIGAPL
policy, they should be available free of change once they are up.

-David E. Siegel



Sat, 14 Feb 2004 05:01:25 GMT  
 
 [ 15 post ] 

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