804829.fig.004
Figure 4: (a) Chain code for a section of a link. To calculate 𝑝 and 𝑞 , a corresponding right angle of reference is needed; the configurations (b) to (f) illustrate the cases ( 𝑝 , 𝑞 ) = ( 4 , 1 ) , ( 3 , 1 ) , ( 4 , 3 ) , ( 1 , 3 ) ; and ( 2 , 3 ) .