See also:
http://www.jsoftware.com/jwiki/Essays/Linear_Recurrences



----- Original Message -----
From: Roger Hui <[EMAIL PROTECTED]>
Date: Monday, August 7, 2006 9:37 pm
Subject: Re: [Jprogramming] conventional way of matrix power?

> A faster (that is, O(2^.n)) method obtains through
> repeated squaring:
> 
>   A=: >1 2; 3 4
>   mp=: +/ .* 
>   mp/ 10 # ,: A
> 4783807  6972050
> 10458075 15241882
>   A&mp^:10 =i.#A
> 4783807  6972050
> 10458075 15241882
>   
>   mpow=: 4 : 'mp/ mp~^:(I.|.#:y) x'
>   A mpow 10
> 4783807  6972050
> 10458075 15241882
> 
> See in the J Wiki:
> http://www.jsoftware.com/jwiki/Essays/Repeated_Squaring



> ----- Original Message -----
> From: June Kim <[EMAIL PROTECTED]>
> Date: Monday, August 7, 2006 7:01 pm
> Subject: [Jprogramming] conventional way of matrix power?
> 
>   A=: >1 2;3 4
>   (+/ . *)/ 10 2$A   NB. A^10
> 4783807  6972050
> 10458075 15241882
> 
> Is this conventional in J? (I guess not)


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