Software visualizations can provide a concise overview of a complex software system. Unfortunately, since software has no physical shape, there is no natural'' mapping of software to a two-dimensional space. As a consequence most visualizations tend to use a layout in which position and distance have no meaning, and consequently layout typical diverges from one visualization to another. We propose a consistent layout for software maps in which the position of a software artifact reflects its vocabulary, and distance corresponds to similarity of vocabulary. We use latent semantic indexing (LSI) to map software artifacts to a vector space, and then use multidimensional scaling (MDS) to map this vector space down to two dimensions.The resulting consistent layout allows us to develop a variety of thematic software maps that express very different aspects of software while making it easy to compare them. The approach is especially suitable for comparing views of evolving software, since the vocabulary of software artifacts tends to be stable over time.
This paper presents a 3D visualization approach which gravitates around the city metaphor, i.e., an object-oriented software system is represented as a city that can be traversed and interacted with: the goal is to give the viewer a sense of locality to ease program comprehension. The key point in conceiving a realistic software city is to map the information about the source code in meaningful ways in order to take the approach beyond beautiful pictures. We investigated several concepts that contribute to the urban feeling, such as appropriate layouts, topology, and facilities to ease navigation and interaction. We experimented our approach on a number of systems, and present our findings.