712 CHAPTER 23. GRAPH DRAWING AND CARTOGRAPHY
usual zoom operation where the user sees only a fraction of the original map
and, hence, loses overview. The difficulty lies in squeezing the remaining part of
the map such that distortion is acceptable.
Cable plans are used for documenting the layout of communication networks. They
are drawn orthogonally and try to preserve the angles, but not the distances of
the original embedding.
Compared to the orthogonal drawing of (embedded) graphs [Tam87], the introduction of
diagonals yields drawings that are more similar to the original embedding. In addition, the
maximum node degree increases from 4 to 8. In a sense, however, the problem becomes
more difficult as Bodlaender and Tel [BT04] point out. They define