I want to draw a graph of sales over time. However, the time periods I have available to me overlap. For example:
- January 2012 to January 2013: 10 million
- April 2012 to April 2013: 12 million
- July 2012 to July 2013: 14 million
- October 2012 to October 2013: 12 million
The obvious way to draw the graph is to do a simple line or bar chart, with the periods as labels on the y-axis:
(of course, the y-axis should begin at zero too!)
But this doesn't feel quite right, because it doesn't really show what's really going on - it looks like a discrete set of points, not an overlapping set of periods.
Is there a better way to visualise overlapping time periods?