Hi Duncan, Thanks for your replay. I am confused as I dont have the quaternion backgorund.
Let me explain what I am trying to do: I have 3 coordinates in space (x1,y1,z1),(x2,y2,z2), and (x3,y3,z3) . Now, I use (x1,y1,z1) and (x2,y2,z2) to define axis of rotaion. Then, I wanted to use 3rd coordinate to calculate angle of rotation about that axis. Is it possible with your orientlib? With regards, Abu ----------------------------------------> Date: Mon, 1 Oct 2007 06:50:35 -0400> From: [EMAIL PROTECTED]> To: [EMAIL PROTECTED]> CC: r-help@r-project.org> Subject: Re: [R] orientlib>> On 01/10/2007 3:31 AM, Abu Naser wrote:>> Hi all users,>>>> I want to calculate angles from two vector using quaternion. I believe , it is possible using orientlib. Since>> I am not an quaternion expart, I need assistance to make sure I am not doing anything wrong. Could anyone please>> expain it how to do it using orientlib.>>> x <- quaternion(c(1,0,0,0))>> y <- quaternion(c(0,1,0,0))>> rotation.distance(x,y)> [1] 3.141593>> But this doesn't calculate angles between vectors, it calculates angles> between orientations. See>> Murdoch, D. (2003). Orientlib: an R package for orientation data.> Journal of Statistical Software, 8(19), 1-11.>> for details.>> Duncan Murdoch _________________________________________________________________ Get free emoticon packs and customisation from Windows Live. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
