A temporal raster plot is a graphic representation of occurrences in a certain temporal relation. Temporal raster plots are also sometimes referred to as
carpet plot
A carpet plot is any of a few different specific types of plot. The more common plot referred to as a carpet plot is one that illustrates the interaction between two or more independent variables and one or more dependent variables in a two-di ...
s.
Each occurrence is registered in a Cartesian coordinate system, in which both axes show time, have different time resolutions: one axis shows slices of data, the other some sensible interval. A common example would be that one axis shows hours in a day, the other days in a year.
In a 2D plot, the value to be plotted is coded with an intensity or a color. In the 3D variant of the plot, it is often coded as a height.
When visualized, particularly the color-coded variant of the plot may easily show a
carpet
A carpet is a textile floor covering typically consisting of an upper layer of pile attached to a backing. The pile was traditionally made from wool, but since the 20th century synthetic fibers such as polypropylene, nylon, or polyester hav ...
-like pattern.
Temporal raster plots make it easy to show time-based relations within a large sets of time-interval data and often make it easy to recognize local
maxima and minima
In mathematical analysis, the maxima and minima (the respective plurals of maximum and minimum) of a function, known collectively as extrema (the plural of extremum), are the largest and smallest value of the function, either within a given r ...
. Assuming that the chosen time division is related to the events, it is also easy to recognize global and local patterns, such as recurrent events.
In the following example, the data is one year's worth of measurements of the outdoor temperatures in
Augsburg
Augsburg (; bar , Augschburg , links=https://en.wikipedia.org/wiki/Swabian_German , label=Swabian German, , ) is a city in Swabia, Bavaria, Germany, around west of Bavarian capital Munich. It is a university town and regional seat of the '' ...
, with four samples taken per hour. In the according carpet diagram, each column represents a day in the year and contains the values for that day (from 0:00 until 23:45).
Despite the high number of measure points (about ), it is easy to distinguish local and global patterns.
References
External links
* {{Commonscatinline
Matlab Script to create temporal-raster carpet plots
Statistical charts and diagrams