calc_Gamma_reduced

% reduced Plückermatrix from Plücker vector
 see PCV (7.132) ff

 Usage
   [Gr , Rm] = calc_Gamma_reduced(L)

   L - 6x1 Plücker Line
   Gr - 2x4 reduced Gamma matrix / reduced Plückermatrix
   Rm - 2x4 reduction matrix

 Wolfgang Förstner 02/2010
 wfoerstn@uni-bonn.de 

 See also calc_Gamma, calc_Gammadual, calc_Gammadual_reduced,
 calc_Pi calc_Pidual, calc_Dual

0001 %% reduced Plückermatrix from Plücker vector
0002 % see PCV (7.132) ff
0003 %
0004 % Usage
0005 %   [Gr , Rm] = calc_Gamma_reduced(L)
0006 %
0007 %   L - 6x1 Plücker Line
0008 %   Gr - 2x4 reduced Gamma matrix / reduced Plückermatrix
0009 %   Rm - 2x4 reduction matrix
0010 %
0011 % Wolfgang Förstner 02/2010
0012 % wfoerstn@uni-bonn.de
0013 %
0014 % See also calc_Gamma, calc_Gammadual, calc_Gammadual_reduced,
0015 % calc_Pi calc_Pidual, calc_Dual
0016 
0017 function [Gr , Rm] = calc_Gamma_reduced(L)
0018 
0019 [~,i] = max(abs(L));
0020 G = calc_Gamma(L);
0021 
0022 switch i 
0023     case 4
0024         Rm = [0 1 0 0;0 0 1 0];
0025         Gr = G([2,3]',:);
0026     case 5
0027         Rm = [1 0 0 0;0 0 1 0];
0028         Gr = G([3,1]',:);
0029     case 6
0030         Rm = [1 0 0 0;0 1 0 0];
0031         Gr = G([1,2]',:);
0032     case 1
0033         Rm = [1 0 0 0;0 0 0 1];
0034         Gr = G([1,4]',:);
0035     case 2
0036         Rm = [0 1 0 0;0 0 0 1];
0037         Gr = G([2,4]',:);
0038     case 3
0039         Rm = [0 0 1 0;0 0 0 1];
0040         Gr = G([3,4]',:);
0041 end