An area chart or area graph displays graphically quantitative data. It is based on the
line chart
A line chart or line graph, also known as curve chart, is a type of chart that displays information as a series of data points called 'markers' connected by straight wikt:line, line segments. It is a basic type of chart common in many fields. ...
. The area between axis and line are commonly emphasized with colors, textures and hatchings. Commonly one compares two or more quantities with an area chart.
History
William Playfair
William Playfair (22 September 1759 – 11 February 1823) was a Scottish engineer and political economist. The founder of graphical methods of statistics, Playfair invented several types of diagrams: in 1786 he introduced the line, area and ...
is usually credited with inventing the area charts as well as the
line,
bar
Bar or BAR may refer to:
Food and drink
* Bar (establishment), selling alcoholic beverages
* Candy bar
** Chocolate bar
* Protein bar
Science and technology
* Bar (river morphology), a deposit of sediment
* Bar (tropical cyclone), a laye ...
, and
pie chart
A pie chart (or a circle chart) is a circular Statistical graphics, statistical graphic which is divided into slices to illustrate numerical proportion. In a pie chart, the arc length of each slice (and consequently its central angle and area) ...
s. His book ''The Commercial and Political Atlas'', published in 1786, contained a number of
time-series
In mathematics, a time series is a series of data points indexed (or listed or graphed) in time order. Most commonly, a time series is a sequence taken at successive equally spaced points in time. Thus it is a sequence of discrete-time data. E ...
graphs, including ''Interest of the National Debt from the Revolution'' and ''Chart of all the Imports and Exports to and from England from the Year 1700 to 1782'' that are often described as the first area charts in history.
Common uses
Area charts are used to represent cumulated totals using numbers or percentages (stacked area charts in this case) over time.
Use the area chart for showing trends over time among related attributes. The area chart is like the plot chart except that the area below the plotted line is filled in with color to indicate volume.
When multiple attributes are included, the first attribute is plotted as a line with color fill followed by the second attribute, and so on.
Variations
Area charts which use vertical and horizontal lines to connect the data points in a series forming a step-like progression are called ''step-area charts''.
Area charts in which data points are connected by smooth curves instead of straight lines are called ''spline-area charts''.
Stacked area charts in which the area is displaced around the central axis are called
''streamgraphs''.
References
Diagrams
Statistical charts and diagrams
{{statistics-stub