[Jprogramming] Another Problem to Sharpen J Skills

[Raul Miller]

I think it's kind of mean to suggest that people who can understand ?6
2$10 are human while people who can understand 6 2 ?@$ 10 are not.

That said, I do understand that students can be mean, and that peer
pressure is a thing.

Thanks,

-- 
Raul



On Sat, Sep 2, 2017 at 1:55 PM, Linda Alvord <lindaalvord at verizon.net> wrote:
> I'll side with the humans.
>
> ?6 2$10
>
> Linda
>
> -----Original Message-----
> From: Programming [mailto:programming-bounces at forums.jsoftware.com] On Behalf Of Henry Rich
> Sent: Saturday, September 2, 2017 12:50 PM
> To: Programming forum <programming at jsoftware.com>
> Subject: Re: [Jprogramming] Another Problem to Sharpen J Skills
>
> Better
>
> 6 2 ?@:$ 10
>
> which Is backed by special code.
>
> Henry Rich
>
>
> On Sep 1, 2017 04:03, "'Mike Day' via Programming" < programming at jsoftware.com> wrote:
>
> I forgot to point out earlier that
>
>      6 12 $ ? 72 $ 10
>
> may be defined more succinctly as
>
>      ? 6 12 $ 10
>
> FWIW,  I had a look at an alternative approach,  working on the union of all rows:
>
>     union =: ~.@:,     NB. ie nub of the ravel
>
>     rix =: (] #~ */@:(e."1)~) union   NB. another row intersection verb
>
>
> It works,  but is more verbose,  uses more memory and more cp time for the limited
>
> cases I've explored.
>
>
> Mike
>
>
>
>
>
> On 01/09/2017 08:40, 'Mike Day' via Programming wrote:
>
>> The main requirement is to obtain the set-intersection of the rows:
>>
>>    rowintersection =: ([-.-.)&~./
>>
>> (The &~. isn't essential,  but it will save space for large arrays
>> with significant repetition.)
>>
>>
>> (Drafting this,  I see Raul's beaten me to it,  though he didn't
>> include the &~. !!!)
>>
>>
>> Also,
>>
>>     colintersection =: rowintersection@:|:
>>
>>
>>
>> Cheers,
>>
>>
>> Mike
>>
>>
>>
>>
>> On 01/09/2017 07:48, Skip Cave wrote:
>>
>>>   ]a =: 6 12$ ?72$10
>>>
>>
>>
>>
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