What might be of general interest to many is a clear description of how 13 :
converts explicit expressions to tacit.
I realize we can look up the C code but the same procedure expressed in J would
be highly educational to newcomers and old hands alike.
Job
Sent from my iPhone
> On Sep 11, 2018, at 8:22 AM, Linda Alvord <lindaalvor...@outlook.com> wrote:
>
> I think the forum would be much more effective if more posts were explicit.
> 13 : . Then new uses could view any tacit impovements.
>
> You wouldn't teach English speaking students Spanish by starting with the
> most complex Spanish sentences you can find.
>
> Also, since I still can't start a new thread, could you move this to a new
> thread?
>
> Linda
>
> a
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> Sent from my Verizon, Samsung Galaxy smartphone
> -------- Original message --------
> From: Henry Rich <henryhr...@gmail.com>
> Date: 9/11/18 9:00 AM (GMT-05:00)
> To: programm...@jsoftware.com
> Subject: Re: [Jprogramming] Tacit form: How to handle intermediate
>
> When I first saw the question 'How would you make this tacit' my
> reaction was 'Why would you ever want to, since the explicit version is
> so easy to understand?'
>
> For practice, maybe. That's a good reason. But if you are trying to
> tune up your tacit forms, you really have to get over any aversion to @
> . The equivalent to
>
> u@v
>
> is
>
> ([: u v)"v
>
> Not only is this butt-ugly, it is not recognized by the interpreter, so
> you miss out on all the fast code for things like <@v ;@:(<@v) etc.
>
> Henry Rich
>
>> On 9/11/2018 5:15 AM, 'Mike Day' via Programming wrote:
>> NB. I've purged most of the earlier posts (below)
>>
>> Martin Kreuzer's original question was how to handle intermediate
>> results!
>>
>> Anyway, staying off topic for now, Ric's tongue-in-cheek proposal is
>> "explicit",
>> but perhaps you wanted something more so, Linda.
>>
>> He's got a point, though - would you like it reexpressed in COBOL?
>>
>> Meanwhile, this _might_ be along the lines you're thinking of:
>>
>> NB. Ric's tacit verb
>> pmt=: {: * 1&{ (([: (% <:) (^~ >:)) * ]) 1200 %~ {.
>>
>> NB. attempt to render it explicit... (explicate it?)
>> pmte =: 3 : 0
>> 'r t b' =. y % 1200 1 1
>> NB. OR: b =. {:y [ t =. 1{y [ r =: 1200%~ {:y NB.!!!
>> NB. (^~ >:) ===>
>> incrtot =. t^~1 + r
>> NB. OR: =. (1 + r)^t
>> NB. ([: (% <:) (^~ >:)) ===> incrtot % incrtot - 1
>> NB. (([: (% <:) (^~ >:)) * ]) ===> (incrtot % incrtot - 1) * r
>> NB. whole thing ===>
>> b * (incrtot % incrtot - 1) * r
>> )
>>
>> BTW, the fragment, incrtot % incrtot - 1, suggests a further refinement -
>> or is it? - dealing with an intermediate result, anyway!
>> incrtot % incrtot - 1
>> 1 % 1 - 1 % incrtot
>> % 1 - % incrtot
>> -.&.% incrtot NB. too tacit?
>>
>> NB. Also, my antiallergenic tacit version avoiding @ and @:
>> pmtmd =: [: (*`(] * [: (% <:) (^~ >:))/) 1 1 1200 %~ |.
>>
>> 'r t b'=. 5.75 240 12500
>> (pmt, pmte, pmtmd) r,t,b
>> 87.7604 87.7604 87.7604
>>
>> FWIW!
>>
>> Mike
>>
>>
>>> On 11/09/2018 07:58, Ric Sherlock wrote:
>>> Linda,
>>> You may want to define exactly what you mean by "explicitly" and what
>>> you're trying to show/achieve.
>>> Here is a tongue-in-cheek potential solution to your request:
>>>
>>> pmt=: 13 : '({: * 1&{ (([: (% <:) (^~ >:)) * ]) 1200 %~ {.) y'
>>>
>>> On Tue, Sep 11, 2018 at 2:21 PM Linda Alvord <lindaalvor...@outlook.com>
>>> wrote:
>>>
>>>> Now can someone, not Ric, write his version explicitly.
>>>>
>>>> PMT=: 13 :
>>>> Linda
>>>>
>>>> Sent from my Verizon, Samsung Galaxy smartphone
>>>>
>>>>
>>>> -------- Original message --------
>>>> From: Ric Sherlock <tikk...@gmail.com>
>>>> Date: 9/10/18 7:04 PM (GMT-05:00)
>>>> To: Programming JForum <programm...@jsoftware.com>
>>>> Subject: Re: [Jprogramming] Tacit form: How to handle intermediate
>>>>
>>>> Without @, but IMO this is a case where @ definitely improves
>>>> readability!
>>>>
>>>> pmt=: {: * 1&{ (([: (% <:) (^~ >:)) * ]) 1200 %~ {.
>>>>
>>>>
>>>> On Tue, Sep 11, 2018 at 7:06 AM Linda Alvord
>>>> <lindaalvor...@outlook.com>
>>>> wrote:
>>>>
>>>>> What if I'm allergic to @ ?
>>>>>
>>>>> Linda
>>>>>
>>>>>
>>>>>
>>>>>
>> [snipped the rest - Mike]
>>
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