Bill:

I cannot get any of the commands from 
http://www.jsoftware.com/jwiki/Plot/Commands to produce a file or output to 
clipboard in j802qt, jhs or j6.  When passed to plot command (have not tried pd)

David:
Some of the more interesting drawings do remind of spirograph in a shakier 
universe

90 d 15 15 15 190 15 15

other classes don't seem to be possible from the spirograph world
90 d 1 1 1 178 1 15
and small tweaks bring an inbetween world

90 d 15 15 15 190 15 15 15

Maybe a good name for this is spiroturtles

Brian:
Adverbs have always had this behavioural subtlety.  Its very powerful, but also 
essential to understanding how they will behave within locales.  The rule of 
thumb is if your explicit adverb doesn't refer to x or y and it returns a verb, 
that verb is tacit

  + 1 : 'u' 
+ 

  + 1 : 'u y' 
+ (1 : 'u y') 


The former "parses away" the adverb.  The latter returns an expression that 
will be parsed by the caller, and so any names referred in the adverb 
definition need to exist in caller's locale (likely to crash as its not a 
normally intended pattern).  But if you don't refer to y, your adverb can refer 
to names in the locale it is defined in.

There is also an efficiency advantage to parsing to a tacit verb, as the 
resulting expression can be applied at low ranks without any reparsing.


----- Original Message -----
From: Brian Schott <[email protected]>
To: Programming forum <[email protected]>
Cc: 
Sent: Saturday, April 18, 2015 7:39 PM
Subject: Re: [Jprogramming] an interesting plot toy

Pascal,

I have been following this thread with some interest, but until just now I
missed your comment that the derivation of the adverb `points` "creates a
tacit verb:". I have never noticed such before, but I have confirmed that
the resulting verb is tacit. My question to all is since when did J start
doing that? I am just wondering how long I have been unaware, but don't
need an exact answer.

​Thanks,​


On Sat, Apr 18, 2015 at 11:10 AM, 'Pascal Jasmin' via Programming <
[email protected]> wrote:

> clever stuff thanks,
>
> here is an adverb form for the clock precision function. m is the number
> of points on the clock up to 90 degrees.  The input is structured that way
> so that the requirement that it be a multiple of 4 is removed.
>
>
>
> points =: 1 : '((4*m)|[+{:@]) ,~ (2&{.)@] + (3 : ''|:(,:y|.])(,-)}:y-|i:
> y'' m) {~ (4*m)|[+{:@]'
>
> creates a tacit verb:
>
>   1 points
> (4 | [ + {:@]) ,~ 2&{.@] + (4 2$0 1 1 0 0 _1 _1 0) {~ 4 | [ + {:@]
>
>
> --
(B=)
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