Vega and Vega-Lite visualisation grammars explained

Vega and Vega-Lite
Logo Caption:	Vega (top), Vega-Lite (bottom)
Developer:	Jeffrey Heer, Arvind Satyanarayan, Dominik Moritz, Kanit Wongsuphasawat, and community
Latest Release Version:	5.25.0
Latest Release Date:	^[1]
Programming Language:	JavaScript
Genre:	Data visualization, JavaScript library
License:	BSD

Vega and Vega-Lite are visualization tools implementing a grammar of graphics, similar to ggplot2. The Vega and Vega-Lite grammars extend Leland Wilkinson's Grammar of Graphics.^[2] by adding a novel grammar of interactivity to assist in the exploration of complex datasets.

Vega acts as a low-level language suited to explanatory figures (the same use case as D3.js), while Vega-Liteis a higher-level language suited to rapidly exploring data.^[3] Vega is used in the back end of several data visualization systems, for example Voyager.^{[4] [5]} Chart specifications are written in JSON and rendered in a browser or exported to either vector or bitmap images. Bindings for Vega-Lite have been written for in several programming languages, for examplethe python package Altair ^[6] to make it easier to use. The grammars and associated tools are open source projects led by the University of Washington Interactive Data Lab and released under a BSD-3 license.^[7]

Notes and References

1. Web site: vega Releases. Github.com.
2. Book: Wilkinson . Leland . The Grammar of Graphics . 1999 . Springer . New York . 9780387987743.
3. Vega-Lite: A Grammar of Interactive Graphics. 10.1109/TVCG.2016.2599030. 2017. Satyanarayan. Arvind. Moritz. Dominik. Wongsuphasawat. Kanit. Heer. Jeffrey. IEEE Transactions on Visualization and Computer Graphics. 23. 1. 341–350. 27875150. 206805969.
4. Voyager: Exploratory Analysis via Faceted Browsing of Visualization Recommendations. 10.1109/TVCG.2015.2467191. 2016. Wongsuphasawat. Kanit. Moritz. Dominik. Anand. Anushka. MacKinlay. Jock. Howe. Bill. Heer. Jeffrey. IEEE Transactions on Visualization and Computer Graphics. 22. 1. 649–658. 26390469. 2366653.
5. Book: https://doi.org/10.1145/3025453.3025768. 10.1145/3025453.3025768. Voyager 2. Proceedings of the 2017 CHI Conference on Human Factors in Computing Systems. 2017. Wongsuphasawat. Kanit. Qu. Zening. Moritz. Dominik. Chang. Riley. Ouk. Felix. Anand. Anushka. MacKinlay. Jock. Howe. Bill. Heer. Jeffrey. 2648–2659. 9781450346559. 14999239.
6. 10.21105/joss.01057. Altair: Interactive Statistical Visualizations for Python. 2018. Vanderplas. Jacob. Granger. Brian. Heer. Jeffrey. Moritz. Dominik. Wongsuphasawat. Kanit. Satyanarayan. Arvind. Lees. Eitan. Timofeev. Ilia. Welsh. Ben. Sievert. Scott. Journal of Open Source Software. 3. 32. 1057. 2018JOSS....3.1057V. free.
7. Web site: Vega: A Visualization Grammar. Vega.