Re: [Algorithms] approximation to pow(n,x)?

[Richard F. <ra...@gm...>]

I'm generally having a problem with the definition of the problem. Curve for
me defines that this is a differentiation, but i feel that it's probably
not. Not using clever bit ops seems pointless if you're after a lot of
speed, and a lookup table might be more expensive because of the memory
access.

I think we need the problem defined better. Give us some context!

2009/11/4 Oscar Forth <os...@tr...>

>  x^m = exp(m log x)
>
> So really you need a fast exp and log function.
>
> Can you newton-raphson refine a log and exp calculation?  I've never tried
> ... perhaps someone else can help there.
>
> Failing that you could probably use tables for the calculations though
> this, obviously, limits the range of powers you can perform.
>
> 2009/11/4 Juan Linietsky <re...@gm...>
>
> Hi guys! I was wondering if there are fast ways to approximate the
>> curve resulting from pow(n,x) where n is in range [0..1] and x > 0
>> using only floating point (without strange pointer casts/etc)..
>>
>> Cheers
>>
>> Juan Linietsky
>>
>>
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