First Question: magnitude as position on a common scale.
Sample from:
https://github.com/jiahuang/d3-timeline
Second Question: magnitude as area.
Norfolk's weather last week (Feb 7-13). Data:
https://www.wunderground.com/history/airport/KORF/2016/2/13/WeeklyHistory.html
Third Question: identity as color hue.
Fourth Question: identity as spatial region.
Refereces:
- Gantt chart:
https://github.com/jiahuang/d3-timeline
- Legend:
https://d3-legend.susielu.com/#color
- Mouse hover:
https://bl.ocks.org/mbostock/3902569
- Read csv file:
https://learnjsdata.com/read_data.html