Timeline charts with googleVis
Last year at the Google I/O conference Mitchell Foley presented new developments of the Google Chart Tools API and one of the new features he mentioned were timeline charts (about 6 min into the talk).
Timeline charts are a great way of visualising different dates/events over time and are now also supported by googleVis from version 0.5.0 onwards (currently only available from GitHub). Here is an example, showing classroom allocation in the afternoon. The exact times and durations are given when you hover over the bars.
I can swap around the bar and row labels to show the rooms by languages:
Here is another example, inspired by Jason Bryer’s timeline package, showing the US presidents and UK prime ministers during World War II. For
gvisTimeline I have to remove the line breaks in Jason’s data.
R version 3.0.3 (2014-03-06) Platform: x86_64-apple-darwin10.8.0 (64-bit) locale:  en_GB.UTF-8/en_GB.UTF-8/en_GB.UTF-8/C/en_GB.UTF-8/en_GB.UTF-8 attached base packages:  stats graphics grDevices utils datasets methods base other attached packages:  timeline_0.9 ggplot2_0.9.3.1 googleVis_0.5.0-3 loaded via a namespace (and not attached):  colorspace_1.2-3 dichromat_2.0-0 digest_0.6.3 grid_3.0.3  gtable_0.1.2 labeling_0.2 MASS_7.3-29 munsell_0.4.2  plyr_1.8 proto_0.3-10 RColorBrewer_1.0-5 reshape2_1.2.2  RJSONIO_1.0-3 scales_0.2.3 stringr_0.6.2 tools_3.0.3