Placing connected components of disconnected graphs

A problem arising when drawing disconnected graphs, is the placement of the connected components. The problem corresponds to finding an appropriate two-dimensional, non-overlapping placement of given objects. Most layout algorithms assume a connected graph and do not deal with connected components. Thus, each component is laid out separately which requires an additional step to arrange these components. There are only few approaches in literature which address this task. We review some of them and present new methods that improve existing results. Our approach is based on a classical greedy approach described by Freivalds et al. which uses a polyomino representation of the objects. We introduce new quality measures to evaluate a two-dimensional placement which yield more compact layouts. Our approach particularly eliminates most cases in which previous approaches returned poor results.