gusucode.com > 《MATLAB图像与视频处理实用案例详解》代码 > 《MATLAB图像与视频处理实用案例详解》代码/第 19 章 基于语音识别的信号灯图像模拟控制技术/voicebox/roteu2qr.m
function q=roteu2qr(m,t) %ROTEU2QR converts a sequence of euler angles to a real unit quaternion % Inputs: % % M(1,n) a string of n characters from the set {'x','y','z'} % or, equivalently, a vector whose elements are 1, 2, or 3 % T(1,n) n rotation angles % % Outputs: % % Q(1,4) output quaternion % % The string M specifies the axes about which the rotations are performed. % You cannot have the same axis in adjacent positions and so there are 12 % possibilities. Common ones are "ZXZ" and "ZYX". A positive rotation is clockwise % if looking along the axis away from the origin. % Suggestions: % (1) Should allow 1,2,3 as well as x,y,z to specify the axes % % Copyright (C) Mike Brookes 2007 % Version: $Id: roteu2qr.m,v 1.2 2007/11/21 12:42:36 dmb Exp $ % % VOICEBOX is a MATLAB toolbox for speech processing. % Home page: http://www.ee.ic.ac.uk/hp/staff/dmb/voicebox/voicebox.html % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % This program is free software; you can redistribute it and/or modify % it under the terms of the GNU General Public License as published by % the Free Software Foundation; either version 2 of the License, or % (at your option) any later version. % % This program is distributed in the hope that it will be useful, % but WITHOUT ANY WARRANTY; without even the implied warranty of % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the % GNU General Public License for more details. % % You can obtain a copy of the GNU General Public License from % http://www.gnu.org/copyleft/gpl.html or by writing to % Free Software Foundation, Inc.,675 Mass Ave, Cambridge, MA 02139, USA. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% y=[2 4 1 3 1 3 2 4; 3 2 1 4 1 4 3 2; 3 4 2 1 1 2 4 3]; % m consists of a sequence of axes e.g. 'zxy' % and t gives the rotation angles in radians q=[1 0 0 0]'; if ischar(m) m=lower(m)-'w'; end if any(abs(m-2)>1), error('Euler axis must be x,y or z'); end for i=1:length(m) x=y(m(i),:); b=0.5*t(i); c=cos(b); s=sin(b); r=zeros(4,1); r(x(1:2))=q(x(3:4)); r(x(5:6))=-q(x(7:8)); q=c*q+s*r; end f=find(q~=0); if (q(f(1))<0), q=-q; end