quattrim.m

This diskette (version 1.0) contains demonstration programs and source codes in MATLAB (v.5.2) for a

function Q = quattrim(Q0)
%
% forces "near quaternion" matrix to be a quaternion matrix
%
Q = (Q0(1,1)+Q0(2,2)+Q0(3,3)+Q0(4,4))/4*eye(4) + (-Q0(1,2)+Q0(2,1)-Q0(3,4)+Q0(4,3))/4*[0,-1,0,0;1,0,0,0;0,0,0,-1;0,0,1,0] + (-Q0(1,3)+Q0(2,4)+Q0(3,1)-Q0(4,2))/4*[0,0,-1,0;0,0,0,1;1,0,0,0;0,-1,0,0] + (-Q0(1,4)-Q0(2,3)+Q0(3,2)+Q0(4,1))/4*[0,0,0,-1;0,0,-1,0;0,1,0,0;1,0,0,0];