
272 CHAPTER 8. SPINE AND RADIAL DRAWINGS
identified by the fan triplet can be recursively drawn. We conclude by mentioning that
based on Theorem 8.11 upright 2-layer, 0-bend drawable graphs can be recognized in linear
time and that, when the two paired curves are two circles, an upright 2-radial, 0-bend
drawing can be computed in linear t ime [DGL08].
λ
i
λ
e
W
u
λ
i
λ
e
v
0
u
v
2
v
4
v
6
v
1
v
3
v
5
W
v
1
W
v
3
W
v
5
(a) (b)
Figure 8.20 (a) A wedge W
u
defined on two pair ed curves. (b) A 2-layer, 0-bend drawing of
the fan F
u
of Figure 8.19 inside W
u
.
Di Giacomo et al. [DDL08b] studied k-radial drawings of graphs with assigned layers and
a prescribed assignment of vertices to the layers. ...