I am an APL + user from way back and have run into the limits of what I have 
(V11 dos based &64 bit win7 don't get along and dosbox is a pain.I know that 
there are more modern APL's but  since I am retired, I am spending my money 
on wine which I can share with my spouse and friends rather than on 
software.  I have written a J script that deals with calculations of 
electric and magnetic fields under power lines- all is good. I can  plot the 
results after some cut and try work to get what I want.

I recognize the potential of J but I do have problems with the non-J 
utilities
I was put on smoutput by someone on the forum in response to a query but 
there are so many potentially useful "verbs"' that are obscure because:

a)they are not well documented

b)documentation tries to be all-fulfilling in a terse manner rather than 
start simply and work up to more complex situations (e.g. to make a simple 
plot, the documentation gives anal discomfort- the information is there but 
buried).

c)  I am too stupid or old to find what I need quickly. There may be the 
rub.

(old applies-first program in MAD in '61, introduced to APL by Ted Edwards, 
in early 70's  and after once writing a program in Pascal and struggling 
with C+ avoided these and their kin because the emphasis was on the details 
of the program structure rather than the logic and  objectives of the 
program).



Don Kelly

cross out to reply
dhky




-----Original Message----- 
From: Ian Clark
Sent: Monday, August 15, 2011 4:51 PM
To: Programming forum
Subject: Re: [Jprogramming] Scan (expand)

Complete J novices knowing some APL might find this useful (for the
first week or so):
http://www.jsoftware.com/jwiki/APL2JPhraseBook
where '\' is referred-to as {backslash}.

The following is a deeper introduction to J for APLers. Authoritative,
it is more tutorial than reference:
http://www.jsoftware.com/jwiki/Doc/J4APL
...needs to be read through at least once.

A far less formal intro to J for (sceptical) APLers is:
http://www.jsoftware.com/jwiki/IanClark/JinaDay
This emphasises j602 JWD and is less good for j701. No good as a
language reference as such. The References section is probably the
most use.


On Mon, Aug 15, 2011 at 1:08 PM, Gian Medri <[email protected]> wrote:
> Hi!
>
> To expand a vector APL has a primitive "\" to do expansion.
> b=: 1 0 0 1 0 1
> b\1 2 3
> 1 0 0 2 0 3
> b\'abc'
> a  b c
> I didn't find any primitive in J to do this. How can J solve this problem?
>
> Thanks in advance
>
> Gian Medri
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
>
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm 


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For information about J forums see http://www.jsoftware.com/forums.htm

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