An extended spreadsheet paradigm for data visualisation systems, and its implementation
Fabian Nuñez · Open University of Cape Town (University of Cape Town) · 2000
We describe a data visualisation system which uses spreadsheets as its user interface metaphor.Similar systems implemented in the past were hampered by the contradiction between an imperative formula language and the declarative spreadsheet framework.We have analysed spreadsheets from a data visualisation point of view, and built a system that is an improvement over past efforts to combine spreadsheets and data visualisation.Our prototype combines the following three techniques: we store lists of values in each spreadsheet cell; we use the functional programming language Scheme as the formula language and we make use of lazy evaluation.The novel combination of these techniques makes our system consistently declarative in nature, and gives it several advantages such as small, uncluttered visual programs, the ability to deal with arbitrarily large datasets and the use of advanced functional language features.We have demonstrated the validity of our work through examples where real-world data is visualised, and through Green's Cognitive Dimensions Framework, which shows that our extended spreadsheet metaphor is at least as usable as commonly-used dataflow methods. iii 9Hypothetical High-order Evaluation in Spreadsheet 10 Algorithm to Transfonn a Spreadsheet into a Dataflow Diagram 11 Algorithm to Transfonn a Dataflow Diagram into a Spreadsheet 12 ViSSh, the Visualisation Spreadsheet .13 High-order Functions . . .14 The SubSheet Mechanism 15 ID Dragger Example . . .16 "Broad Overview" Window Corresponding to Figure 19 .17 "Cell Dependencies" Window Corresponding to Figure 19 18 Effect of Adding a Time Cell to a Simple Visualisation 19 Simple Parametric Cone Visualisation . . . . .20 ViSSh Layered Design . . . . . . . . . . . . .21 Applying a Transfonn to a Mapping Layer Cell 22 Scene Graph Built by Render Cell . . . . . . .23 Sampling Stations for the KaapVaal Experiment.24 Sample of Seismic Disturbance Dataset 25 Seismic Spreadsheet Dependencies .