
290 CHAPTER 9. CIRCULAR DRAWING ALGORITHMS
u
xv w
u
(b)
xv w
v w
(a)
u
u
v w
u
xv w
counter = i + 1
counter = i
After Step 12
u
v w
counter = i
counter = i + 1
After Step 12
Figure 9.5 The node and edge absorption qualities of Algorithm CIRCULAR. Part (a)
shows a degree-two node u and its neighbors v and w at three different points in the algo-
rithm. Fi r s t, the pair edge established by u, (v, w), is shown. Next, after node u is processed,
node u and edges (u, v) and (u, w) are inherently represented by the edge (v, w). Finally, we
see the same graph fragment after the pair edge (v, w) has been removed in Ste p 14. Part (b)
shows a similar example with a degree-thre ...