3(f=:144"_(***)144"_)4
429981696
3 f 4
429981696
9!:3]4
f
┌─ 144
┌─ " ─┴─ _
│
│ ┌─ *
├─────┼─ *
──┤ └─ *
│
│ ┌─ 144
└─ " ─┴─ _
Linda
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Erling Hellenäs
Sent: Sunday, July 20, 2014 5:24 AM
To: [email protected]
Subject: Re: [Jprogramming] High Speed Train Challenge
3(***(***)(***))4
35831808
3((***))4
144
3(***(***)144"_)4
35831808
3(*)4
12
3(**12"_(***)144"_)4
35831808
12(***)144
2985984
3(**2985984"_)4
35831808
3(12"_*2985984"_)4
35831808
3((***)(***)***)4
429981696
3(144"_(***)144"_)4
429981696
/Erling
On 2014-07-20 02:49, Linda Alvord wrote:
> I'm still looking for the phrase or concept that explains the difference
> between these two. Why are they producing different results?
>
> 3(***(***)(***))4
> 35831808
>
> 3((***)(***)***)4
> 429981696
>
> If you grew up in the early years using APL, an idea might come to mind.
>
> Linda
>
> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]] On Behalf Of 'Pascal
> Jasmin' via Programming
> Sent: Saturday, July 19, 2014 8:34 PM
> To: [email protected]
> Subject: Re: [Jprogramming] High Speed Train Challenge
>
>
>
> 3 * utu utu 4
>
> 3 * 1 : '[: u~ u' 1 : '[: u~ u' 4
> 429981696
>
>
>
> ----- Original Message -----
> From: Kip Murray <[email protected]>
> To: "[email protected]" <[email protected]>
> Cc:
> Sent: Saturday, July 19, 2014 6:55:02 PM
> Subject: Re: [Jprogramming] High Speed Train Challenge
>
> utu =: 1 : '[: u~ u'
> 3 *:@* utu 4
> 429981696
>
> uses the ideas that *** is equivalent to *:@* and u u u is equivalent to [:
> u~ u
>
> On Saturday, July 19, 2014, 'Pascal Jasmin' via Programming <
> [email protected]> wrote:
>
>> I'm not sure I'm arguing for the idea. I've disliked ~ in the past
>> because I've read it as one of the other 2 meanings that was written. I
>> wonder if making reflexive more common would help overcome forgetting it
>> exists quicker.
>>
>> from your examples, it would appear that good candidates for monadic + and
>> * would be +~ and *~. Monadic * and + could have been chosen with +: and
>> *: symbols. We can (fortunately) implement such bivalence ourselves:
>>
>> area =: *~
>>
>> area 8
>> 6 area 8
>>
>>
>> ----- Original Message -----
>> From: robert therriault <[email protected] <javascript:;>>
>> To: [email protected] <javascript:;>
>> Cc:
>> Sent: Saturday, July 19, 2014 6:16:58 PM
>> Subject: Re: [Jprogramming] High Speed Train Challenge
>>
>> Hi Pascal,
>>
>> Not arguing against the idea but they are only functionally the same for
>> monadic.
>>
>> 4 *: 4
>> |domain error
>> | 4 *:4
>> 4 +: 4
>> |domain error
>> | 4 +:4
>> 5 *: 4
>> |domain error
>> | 5 *:4
>> 5 *~ 4
>> 20
>> 5 +: 4
>> |domain error
>> | 5 +:4
>> 5 +~ 4
>> 9
>>
>> Cheers, bob
>>
>>
>> On Jul 19, 2014, at 2:59 PM, 'Pascal Jasmin' via Programming <
>> [email protected] <javascript:;>> wrote:
>>
>>> kindof the same as your idea
>>>
>>> *~(^:3) 12
>>> 429981696
>>>
>>> completely off topic, but would it be a good or bad thing if, assuming
>> there was a shortage of ascii mnemonics, and some need, if monadic +: and
>> *: were redefined considering that +~ and *~ do the same?
>>>
>>> ----- Original Message -----
>>> From: Erling Hellenäs <[email protected] <javascript:;>>
>>> To: [email protected] <javascript:;>
>>> Cc:
>>> Sent: Saturday, July 19, 2014 3:05:03 PM
>>> Subject: Re: [Jprogramming] High Speed Train Challenge
>>>
>>> Another way to do the same thing, but not a solution, is this
> expression:
>>> 3 (*(*(***)*)*) 4 NB. Funny way
>>> 429981696
>>>
>>> Anyone can find a nice recursive way to write it? My best shot:
>>>
>>> 12 1:`([ * [ $: [: <: ])@.([: * ]) 8 NB. Complicated way
>>> 429981696
>>>
>>> It's a recursion? * $: *
>>>
>>> /Erling
>>>
>>>
>>>
>>>
>>> On 2014-07-19 20:48, Raul Miller wrote:
>>>> Probably, yes.
>>>>
>>>> And I was sort of provocative by not going with the implied
> limitations.
>>>> But there's can be quite a bit of ambiguity when key issues are
>>>> implied, rather than addressed or illustrated.
>>>>
>>>> This is a problem I face myself, quite often: How can I be aware of
>>>> important issues which matter to other people, when I am incredibly
>>>> focused on my own point of view?
>>>>
>>>> That said:
>>>>
>>>> (1) Erling Hellenäs had already posted some solutions which satisfied
>>>> the "one verb" constraint using * as that verb (at the time I made my
>>>> 42981696"_ post).
>>>>
>>>> (2) Realizing that derived verbs are J verbs is an important lesson
>>>> which beginning J programmers often overlook.
>>>>
>>>> You can't really be a good J progammer if you don't understand the
>>>> grammar of the language. And it's not that the grammar is hard to
>>>> understand - it's extremely simple. But it's so simple that it's also
>>>> easy to sometimes get by with false generalizations about its rules.
>>>>
>>>> This leads into the almost inevitable "no that's not what I meant"
>>>> sorts of social issues.
>>>>
>>>> So yes, my post was - in a sense - somewhat bratty. But I felt that
>>>> the underlying issue was important enough to raise the point and stick
>>>> with it at least until someone called me on it.
>>>>
>>>> Thanks,
>>>>
>>> ----------------------------------------------------------------------
>>> For information about J forums see http://www.jsoftware.com/forums.htm
>>
>>
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>>
>
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