%TR2JAC Compute a Jacobian to map differentials between frames%%	J = TR2JAC(T)%% Returns a 6x6 Jacobian matrix to map differentials (joint velocity) between % frames related by the homogeneous transform T.%% See also: TR2DIFF, DIFF2TR.% Copyright (C) 1993-2008, by Peter I. Corke%% This file is part of The Robotics Toolbox for Matlab (RTB).% % RTB is free software: you can redistribute it and/or modify% it under the terms of the GNU Lesser General Public License as published by% the Free Software Foundation, either version 3 of the License, or% (at your option) any later version.% % RTB 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 Lesser General Public License for more details.% % You should have received a copy of the GNU Leser General Public License% along with RTB.  If not, see <http://www.gnu.org/licenses/>.function J = tr2jac(t)	J = [	t(1:3,1)'	cross(t(1:3,4),t(1:3,1))'		t(1:3,2)'	cross(t(1:3,4),t(1:3,2))'		t(1:3,3)'	cross(t(1:3,4),t(1:3,3))'		zeros(3,3)	t(1:3,1:3)'		];