[Jprogramming] arithmetic sequence

[Bo Jacoby]

Skips special data does not justify his general conclusion: "The brute force solution is the fastest by several orders of magnitude. The closed form solution is slow AND uses lots of space". Other data give other conclusions.


   closed
[: (,. (3r4 * <:)) 5&^

   (10)   6!:2'closed 5'
1.82306e_5
   (10)   6!:2'((0 3+*&5)^:5)1 0x'
8.04365e_5

   (10)   6!:2'closed 50'
3.68924e_5
   (10)   6!:2'((0 3+*&5)^:50)1 0x'
0.000332709

   (10)   6!:2'closed 500'
2.99943e_5
   (10)   6!:2'((0 3+*&5)^:500)1 0x'
0.00487965


It cannot be concluded that 'closed'   is generally slower than the brute force computation. In the above cases 'closed' is faster. 


- Bo


>________________________________
> Fra: Boyko Bantchev <boykobb at gmail.com>
>Til: programming at jsoftware.com 
>Sendt: 18:21 søndag den 23. december 2012
>Emne: Re: [Jprogramming] arithmetic sequence
> 
>On 23 December 2012 18:06, Bo Jacoby <bojacoby at yahoo.dk> wrote:
>> Skip's conclusion did not follow from his data in the first place.
>
>His conclusion is based on his data for producing a 5000-items long
>sequence.  Not only is it valid but in fact it holds for *all* lengths
>where extended numbers are needed, i.e. practically always.
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