Also, partials can be calculated either way:
*`+/\ 1 2 3 4 5 6 7
1 2 5 14 29 104 209
+`*/\ 1 2 3 4 5 6 7
1 3 7 15 47 95 383
So the "insertion sequence" can be generated in either direction, by
reversing the gerund.
Skip
Skip Cave
Cave Consulting LLC
On Tue, Feb 23, 2016 at 12:38 AM, Skip Cave <[email protected]> wrote:
> I think I'm missing something...
>
> Raul said: "Do we have no way of performing the insertion in the same
> order as the evaluation order? This would be important in constructing
> efficient gerund scans."
>
> There are only two ways to alternatively insert operators in a
> sequence of numbers:
>
> 1*2+3*4+5*6+7
> 209
> 1+2*3+4*5+6*7
> 383
>
> The gerund insert allows inserting the verbs either way:
>
> *`+/ 1 2 3 4 5 6 7
> 209
> +`*/ 1 2 3 4 5 6 7
> 383
>
> Reversing the order of the gerund has the identical effect as
> right-to-left insertion:
> The order that you insert the verbs in the vector shouldn't matter,
> since the execution occurs after all insertions.
>
> What am I missing?
>
> Skip
>
> Skip Cave
> Cave Consulting LLC
>
>
> On Mon, Feb 22, 2016 at 11:38 PM, Raul Miller <[email protected]> wrote:
>> Ok, so we left to right insertion combined with right to left
>> evaluation. That might be "algorithmically interesting" but it also
>> seems unnecessarily complex for some useful cases.
>>
>> Do we have no way of performing the insertion in the same order as the
>> evaluation order? This would be important in constructing efficient
>> gerund scans.
>>
>> And, currently, I'm not seeing any such option - given left to right
>> insertion, we would need left to right evaluation of the insertion for
>> an efficient scan.
>>
>> Argh...
>>
>> --
>> Raul
>>
>>
>> On Mon, Feb 22, 2016 at 11:54 PM, bill lam <[email protected]> wrote:
>>> In DOJ, but inside Introduction part
>>>
>>> http://www.jsoftware.com/help/dictionary/intro21.htm
>>>
>>> to recap,
>>> x=.4
>>>
>>> +`*/1,x,3,x,3,x,1
>>> 125
>>> 1 + x * 3 + x * 3 + x * 1
>>> 125
>>> 1 * x + 3 * x + 3 * x + 1
>>> 61
>>>
>>>
>>> Пн, 22 фев 2016, Raul Miller написал(а):
>>>> http://www.jsoftware.com/help/dictionary/d420.htm says:
>>>>
>>>> m/y inserts successive verbs from the gerund m between items of y,
>>>> extending m cyclically as required. Thus, +`*/i.6 is 0+1*2+3*4+5
>>>>
>>>> But it does not include an example of m/y where y contains an odd
>>>> number of elements.
>>>>
>>>> From the description, I would expect +`*/3 4 5 to give the result 3*4+5
>>>>
>>>> However:
>>>> 3*4+5
>>>> 27
>>>> +`*/3 4 5
>>>> 23
>>>>
>>>> I'm thinking that this might be a bug in the interpreter.
>>>>
>>>> Is there some application, though, that requires the current behavior?
>>>>
>>>> Thanks,
>>>>
>>>> --
>>>> Raul
>>>> ----------------------------------------------------------------------
>>>> For information about J forums see http://www.jsoftware.com/forums.htm
>>>
>>> --
>>> regards,
>>> ====================================================
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>>> gpg --keyserver subkeys.pgp.net --armor --export 4434BAB3
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