Statistical plots drawn with the ggplot2 package generate numerous grid grobs and viewports which are labelled and organised into a coherent hierarchy. This report describes an example that shows how to manipulate the grobs and viewports in a ggplot2 plot using tools from the grid package, export the result to SVG using gridSVG, then manipulate the result further using XML tools, to produce an interactive ggplot2 graphic for the web.
The gridSVG package exports grid images to an SVG format for viewing on the web. This article describes a new development in the way that gridSVG produces the SVG output. The result is greater flexibility in how the SVG output is produced and increased opportunities to manipulate the SVG output, which creates new possibilities for generating more complex and sophisticated dynamic and interactive R graphics for the web.
Simon Potter and Paul Murrell