Multilevel label placement for execution trace events

Automatic label assignment to graphical objects is an important problem in many applications such as cartography, online maps and graph drawings. In this paper, we present efficient algorithms for automatic label assignment to execution trace items (points or lines) in a trace visualization tool. The proposed label assignment algorithms aim to maximize the number of labeled items as well as increase the quality of assignments. The algorithms take into account both the topological and semantic relationships (e.g. level of details, repetitiveness, etc.) between the trace items in order to achieve assignments that are both quantitative and qualitative. The proposed method also supports assigning multiple labels to each trace item. The algorithms have been implemented and applied to different input traces. The experimental results show that considering the relationships between data items increases the labeling success rate and the quality.