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Rockbox mail archiveSubject: Re: Sinus and cosinus functionsRe: Sinus and cosinus functions
From: Paul Suade <paul.suade_at_laposte.net>
Date: Sun, 1 Sep 2002 14:35:42 +0200 SH1 has no float point unit, so you'd better avoid this soultion. And still it is intolerable since it needs to multiply and divide in a loop. ----- Original Message ----- From: "Damien Teney" <dteney_at_hotmail.com> To: <rockbox_at_cool.haxx.se> Sent: Sunday, September 01, 2002 12:47 PM Subject: Re: Sinus and cosinus functions > I've rewritten the sinus (sin()) function. It really calculates the sinus, > without using tables. However, I don't know how fast it is, and I haven't > tried it on my Archos. > If someone could do it... ;-) > > ------------------------- > D a m i e n T e n e y > > dteney_at_hotmail.com > > http://www.mcarsweb.com > ------------------------- > > > > float fabs(float x) > { > return x >= 0 ? x: x*(-1); > } > > float sin(float x) > { > float sum, x_quadrat, rest; > int k; > k = 0; > sum = 0; > rest = x; > x_quadrat = x*x; > while (fabs(rest) > 1e-9) { > sum += rest; > k += 2; > rest *= -x_quadrat/(k*(k+1)); > } > return sum; > } > > > _________________________________________________________________ > Discutez en ligne avec vos amis ! http://messenger.msn.fr > Received on 2002-09-01 Page template was last modified "Tue Sep 7 00:00:02 2021" The Rockbox Crew -- Privacy Policy |