We have taken a prototype-driven research approach in studying how spreadsheet environments can be employed for visualization. To this end, we have constructed two prototype visualization spreadsheet systems.
The first system is a domain-specific study on how spreadsheet can be structured and used in performing specific tasks in analyzing genetic sequence similarity reports, and is called ``Spreadsheet for Similarity Reports'' (SSR). The system is designed for biologists and their task of comparing similarity reports. SSR is built using OpenGL and Motif using C++, and is built upon the ideas in a previous system we call ``AlignmentViewer'' [4, 5]. It includes a computational steering environment for rapidly executing the similarity algorithm on multi-processor machines parallel using different algorithm parameters and importing the data. For analysis, it provides animation, filtering, and variable-to-axis mapping capabilities.
The second system is a general visualization spreadsheet built on top of the Visualization Toolkit (VTK) [25, 26]. We call this system ``Spreadsheet for Information Visualization'' (SIV, pronounced ``sieve''). We chose VTK because it provides an object-oriented architecture with many pre-built objects that we can use for exploring the spreadsheet paradigm. Since VTK can be used in conjunction with the Tcl command language and Tk widget toolkit, it facilitates rapid development in an interpreted environment. The system can also run on multiple platforms since VTK and Tcl/Tk are both available under Unix and Windows 95/NT.