The pie chart diagram dates all the way back to 1801 when
William Playfair produced a publication 'The Statistical
Breviary' that contained the following pie diagram:- Looking at
this early example we can that all the basics of pie chart are
the same today as they were over 200 years ago. The pie is split
into segments where the angle is proportional to the data item
represented. Each segment is colored although today colors used
tend to be far more vibrant. Although widely used today the pie
chart was not immediately taken up. Following William Playfair's
publication the pie did not appear again until 1858 when a
French engineer Charles Joseph Minard began using pie charts to
represent an extra dimension to data. There are today many
variations of the pie chart including Polar Area Diagrams, Spie
Charts, Radial Charts, Exploded pie charts, 3D Pie Charts and
Doughnut Charts. However still the most common use is the simple
pie chart as depicted in these early examples. Here is an
example of a modern use of the