Understanding and interpreting a large data source is an important but challenging operation in many technical disciplines. Computer visualization has become a valuable tool to help capture and portray characteristics of large data sets. In software visualization, illustrating the operation of very large programs or programs working on very large data sets has remained one of the key open problems. Here, we introduce an approach that uses semantic zooming to depict large program executions. Our method utilizes abstract, clustered graphics to portray program operations on the entire data set. Then, by interacting with the presentation, a viewer can zoom in to examine details and individual values. At this "magnified" level, the presentation adjusts to reflect displays common in existing algorithm animation and program visualization systems. 1 Introduction Software Visualization is the use of visualization and animation techniques to help people understand the characteristics and exec...

The general term program visualization refers to graphical views or illustrations of the entities and characteristics of computer programs. This term along with many others including data structure display, program animation, algorithm animation, etc., have been used inconsistently in the literature, which has led to confusion in describing systems providing these capabilities. In this paper we present a scaled characterization of program visualization terms along aspect, abstractness, animation, and automation dimensions. Rather than placing existing systems into hard-and-fast categories, we focus on unique and differentiating aspects across all systems. Keywords: program visualization, algorithm animation, software understanding 1 Introduction A visualization tool provides graphical views of the entities and characteristics of a computer system or program. The purpose of such a visualization tool is stated nicely by Myers, et. al.: "Human information processing is clearly optimized...

Programmers have always been curious about what their programs are doing while it is executing, especially when the behavior is not what they are expecting. Since program execution is intricate and involved, visualization has long been used to provide the programmer with appropriate insights into program execution. This paper looks at the evolution of on-line visual representations of executing programs, showing how they have moved from concrete representations of relatively small programs to abstract representations of larger systems. Based on this examination, we describe the challenges implicit in future execution visualizations and methodologies that can meet these challenges.