function xc = do_proj( x, traj )

% DO_PROJ Performs a projection of a group of points



[ num_samples, m ] = size( x );    %  m should be three !

[ num_times, m ] = size( traj );



xc = zeros( [ num_times, num_samples * 2 ] );



for time = 1:num_times

  index = 1;

  for sample = 1:num_samples

    xc(time, index:(index + 1)) = project( x(sample,:)', traj(time,:) );

    index = index + 2;

  end

end