[Jprogramming] Mersenne Prime initialization.

[butch.lakeshsore at antelecom.net]

time '<: 2x pow 43112609' 

took about 15 hours.

----- Original Message Follows -----
From: Roger Hui <rhui000 at shaw.ca>
To: Programming forum <programming at jsoftware.com>
Subject: Re: [Jprogramming] Mersenne Prime initialization.
Date: Thu, 09 Apr 2009 18:45:58 -0700

>The problem is that multiplication of extended precision
>numbers in J is slow (quadratic).
>
>
>
>----- Original Message -----
>From: butch.lakeshsore at antelecom.net
>Date: Thursday, April 9, 2009 18:15
>Subject: Re: [Jprogramming] Mersenne Prime initialization.
>To: Programming forum <programming at jsoftware.com>
>
>> 
>> I looked over the essay by roger hui and the:
>> 
>> pow=: 4 : '*/ *~^:(I.|.#:y) x'
>> 
>> works ok.
>> 
>> Regreatably,
>> 
>> time '<: 2x pow   1257787' NB. takes ~41.0 sec
>> 
>> I will try::
>> 
>> time '<: 2x pow 43112609' 
>> 
>> overnight and see what it takes.
>> 
>> ----- Original Message Follows -----
>> From: Aai <bradypus at xs4all.nl>
>> To: Programming forum <programming at jsoftware.com>
>> Subject: Re: [Jprogramming] Mersenne Prime
>> initialization. Date: Thu, 09 Apr 2009 20:18:24 +0200
>> 
>> >Sorry, another try:
>> >
>> >http://www.jsoftware.com/jwiki/Essays/Repeated_Squaring
>> >
>> >
>> >-- 
>> >=@@i
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