Thank you for your reply. Impressive result!
I can only come up with:
pmt=:(1,[:/:[EMAIL PROTECTED]@;]<@([EMAIL PROTECTED])"0 0<:@<[EMAIL
PROTECTED])2+i.@<:@<[EMAIL PROTECTED]:
pmx=: 3 : 0
ri=.2+i.<:<.%:y
1,/:~~.;ri<@([EMAIL PROTECTED])"0 0<:<.ri^.y
)
=@@i
R.E. Boss schreef:
> 10 ts'%. 200 200 [EMAIL PROTECTED] 1000' NB. benchmark
> 0.049750737 4330240
>
> pp2=: 3 : '1,/:~~.;<@(^~ 2+i.@<:)/"1 (](],.<[EMAIL PROTECTED]:~) 2([EMAIL
> PROTECTED]@<:) 2<[EMAIL PROTECTED]) y'
> NB. my solution
>
> 10 ts 'pp2 2000000'
> 0.00042491393 98048
>
> ('3.0')(8!:2)%/ 10 ts &>'%. 200 200 [EMAIL PROTECTED] 1000';'pp2 2000000'
> 120 44
> NB. 120 times faster and 44 times leaner than benchmark
>
> You had for pmx:
>
> ('3.0')(8!:2)%/ 0.0865417 3933888,:0.0036827 275712
> 23 14
>
> and for pmt:
>
> ('3.0')(8!:2)%/ 0.0865417 3933888,:0.006247 232448
> 14 17
>
> I checked 'pp 1765' with http://www.research.att.com/~njas/sequences/A001597
> and it matched.
>
>
> R.E. Boss
>
>
>
>> -----Oorspronkelijk bericht-----
>> Van: [EMAIL PROTECTED] [mailto:programming-
>> [EMAIL PROTECTED] Namens Arie Groeneveld
>> Verzonden: maandag 28 januari 2008 11:43
>> Aan: Programming forum
>> Onderwerp: Re: [Jprogramming] Perfect powers
>>
>> Following a wise advise: here's is an indication of the speed of my pc:
>>
>> 10 ts'%. 200 200 [EMAIL PROTECTED] 1000'
>> 0.0865417 3933888
>>
>>
>> @@i schreef:
>>
>>> JATK or let's say J4F.
>>>
>>> Generating a sequence of ordered perfect powers <= N
>>> ref. OLEIS A001597
>>>
>>> I have a tacit (pmt) and a explicit (pmx) version both with the same
>>> algorithm
>>>
>>> *nb* Without ext. prec.
>>>
>>> pmt 200
>>> 1 4 8 9 16 25 27 32 36 49 64 81 100 121 125 128 144 169 196
>>>
>>> 10 ts 'pmt 2000000'
>>> 0.006247 232448
>>>
>>> 10 ts 'pmx 2000000'
>>> 0.0036827 275712
>>>
>>>
>>> x:{: pmx 2e6
>>> 1999396
>>>
>>> #pmt 1e6 NB. OLEIS A070428
>>> 1111
>>>
>>>
>>> Testing if a number > 1 is a perfect power:
>>>
>>> (1<[:+./[:{:__&q:) 220
>>> 0
>>>
>>> (1<[:+./[:{:__&q:) 32
>>> 1
>>>
>>>
>>> Just anxious to know (JATK) what's possible. :-)
>>>
>>>
>>>
>>> =@@i
>>>
>>>
>>> ----------------------------------------------------------------------
>>> For information about J forums see http://www.jsoftware.com/forums.htm
>>>
>>>
>>>
>>>
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>>
>
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