Layout heuristics for graphical representations of programs

A layout problem is formulated for two-column graphs, and a layout algorithm, referred to as an insertion algorithm, for the two-column graph problem is presented. In addition, two variants of the algorithm are presented: dynamic insertion and delta insertion algorithms. The layout algorithms are implemented and experiments performed in order to compared their performance to existing layout algorithms for hierarchical graphs (i.e., exchanging and averaging algorithms). The experimental results show that the insertion method produces significantly better layouts compared to the existing methods. The method has been implemented in two software tools for the development and maintenance of programs, VIC and VIFOR (Visual Interactive C and FORTRAN 77, respectively)