First Question: magnitude as position on a common scale.

Second Question: magnitude as area.

Norfolk's weather last week (Feb 7-13). Data: http://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: http://d3-legend.susielu.com/#color
- Mouse hover: http://bl.ocks.org/mbostock/3902569
- Read csv file: http://learnjsdata.com/read_data.html