% By Philip Torr 2002 % copyright Microsoft Corp. %%%%%%this is going to be my first try at some symbolic stuff %%%the purpose of this file is to set up an essential matrix that you can later do symbolic manipulation of,. syms tx ty tz; Tx = [0 -tz ty; tz 0 -tx; -ty tx 0]; %rodriggues formula a rotation angle l m n axis syms lx ly lz a Id = [1 0 0; 0 1 0; 0 0 1] Ax = [0 -lz ly; lz 0 -lx; -ly lx 0]; rot_axT = [ lx ly lz] rot_ax = [ lx; ly; lz] R = (cos(a) * Id + sin(a) * Ax + (1 - cos(a)) * rot_ax * rot_axT) E = Tx * R syms foc Ca = [1 0 0; 0 1 0; 0 0 foc] G = Ca * E * Ca %det(E) %0.5 * (trace( E * E'))^2 - trace((E * E')^2) syms x1 x2 y1 y2 r = [x2 y2 1] * G * [x1; y1; 1]