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Rockbox mail archiveSubject: Re: Math in RockboxRe: Math in Rockbox
From: Andreas Stemmer <groovingandi_at_gmx.de>
Date: Thu, 7 Jul 2005 08:35:09 +0200 (MEST) lear_at_algonet.se wrote: > For an upcoming patch, I need some fixed- or floating-point math. Does anyone have > a good fixed-point implementation of pow(10, x) (or exp10(x)), or some hints > on how to implement it? It doesn't need to be particularly fast; small size > is to be preferred actually. If x is an integer value, use one of the algorithms already given (lookup table or while loop). If x can be fixed point as well, you could use some kind of taylor approximation: e^x = x^0/0! + x^1/1! + x^2/2! + x^3/3! + ... with 10^x = (e^n)^x = e^(n*x) and n = ln 10 = 2.302585093 for an implementation see http://people.csail.mit.edu/hqm/imode/fplib/FP.java.html Andreas _______________________________________________ http://cool.haxx.se/mailman/listinfo/rockbox Received on 2005-07-07 Page template was last modified "Tue Sep 7 00:00:02 2021" The Rockbox Crew -- Privacy Policy |