% function draw_point( h, xp, color )
% Draw 'xp' points with a color 'color' to the figure 'h'.
function draw_point( h, xp, color )
  
  figure( h )
  hold on;
  for i = 1:size( xp, 2 )
    plot3( xp(1,i), xp(2,i), xp(3,i), color );
  end
