[Csnd] 2^(1/12) and other fractional exponents
Date | 2013-03-14 18:43 |
From | Adam Puckett |
Subject | [Csnd] 2^(1/12) and other fractional exponents |
Hi, I've been wondering how it is that computers analytically calculate such functions as roots, fractional exponents and other such "magic" such as trig functions. Thanks, Adam |
Date | 2013-03-14 19:10 |
From | Martin Huenniger |
Subject | Re: [Csnd] 2^(1/12) and other fractional exponents |
Hi Adam, a common way to compute sine and cosine functions is to use a taylor series expansion. http://en.wikipedia.org/wiki/Taylor_series For the root function a Newton iteration is sometimes used http://en.wikipedia.org/wiki/Newton%27s_method C/C++ uses the Floating-Point-Unit of the processor and so references the functions directly implemented in Hardware/microcode. FPU's use the CORDIC algorithm http://en.wikipedia.org/wiki/Cordic Best, Martin Am 14.03.2013 um 19:43 schrieb Adam Puckett: > Hi, > > > I've been wondering how it is that computers analytically calculate > such functions as roots, fractional exponents and other such "magic" > such as trig functions. > > Thanks, > Adam > > > Send bugs reports to the Sourceforge bug tracker > https://sourceforge.net/tracker/?group_id=81968&atid=564599 > Discussions of bugs and features can be posted here > To unsubscribe, send email sympa@lists.bath.ac.uk with body "unsubscribe csound" > _________________________ Martin Hünniger a_s_tarantoga@yahoo.de a-s-tarantoga.tumblr.com soundcloud.com/a_s_tarantoga |
Date | 2013-03-14 21:19 |
From | jpff@cs.bath.ac.uk |
Subject | Re: [Csnd] 2^(1/12) and other fractional exponents |
> Hi Adam, > > a common way to compute sine and cosine functions is to use a taylor > series expansion. http://en.wikipedia.org/wiki/Taylor_series > But tghe wrong way if you want any decent speed. Tchebychev polynomials is the correct way. Try Code & Waite's book. > For the root function a Newton iteration is sometimes used > http://en.wikipedia.org/wiki/Newton%27s_method > > C/C++ uses the Floating-Point-Unit of the processor and so references the > functions directly implemented in Hardware/microcode. FPU's use the CORDIC > algorithm http://en.wikipedia.org/wiki/Cordic > > Best, > Martin > > Am 14.03.2013 um 19:43 schrieb Adam Puckett: > >> Hi, >> >> >> I've been wondering how it is that computers analytically calculate >> such functions as roots, fractional exponents and other such "magic" >> such as trig functions. >> >> Thanks, >> Adam >> >> >> Send bugs reports to the Sourceforge bug tracker >> https://sourceforge.net/tracker/?group_id=81968&atid=564599 >> Discussions of bugs and features can be posted here >> To unsubscribe, send email sympa@lists.bath.ac.uk with body "unsubscribe >> csound" >> > > _________________________ > Martin Hünniger > a_s_tarantoga@yahoo.de > a-s-tarantoga.tumblr.com > soundcloud.com/a_s_tarantoga > > > > > > > Send bugs reports to the Sourceforge bug tracker > https://sourceforge.net/tracker/?group_id=81968&atid=564599 > Discussions of bugs and features can be posted here > To unsubscribe, send email sympa@lists.bath.ac.uk with body "unsubscribe > csound" > > > > |